How Heat Affects Plants

When it gets hot for a day or two, plants can wilt and require some extra attention. That’s pretty easy to understand. After all, I spend less time outside in the heat of the day because I wilt. I also drink more water. After more than a week of temperatures hovering near or above 100° F, our plants are showing other signs of heat stress that we less often consider.

jimson weed datura new mexico
Jimson weed, or datura, loves heat and drought. Then again, it does have the word “weed” in its name.

You would think that living in the Southwest and having mostly xeric plants means plants can tough it out dor a few hot, dry (windy!) days. That’s partially true. But these temperatures are way above normal, at least for an entire day/week and more. Normally, July 1 marks the beginning of monsoons, where clouds build and drop at least some rain in the afternoon, giving the plants and me a break. Not this year. And it’s causing problems for nearly every living thing in our garden. Here are some reasons why:

Heat can reduce bee populations

We noticed about midway through our current heat wave that we seem to have fewer bees in our garden. Of course, I thought I was imagining that. Nope. Bees are especially sensitive to temperature and its regulation. Temperature particularly affects young bees, which are important for keeping colonies going. They tend to keep their hives at 95° or lower, and stress when the temperatures exceed 98°. Bees also need water, and we’ve had two weeks with no measurable rain and consistently high temperatures, even for our evening lows. Here’s a great explanation from Tufts University on how honey bees keep cool (and warm). Despite the fact that we have plenty of flowering plants for bees beginning in spring, the population is lower this summer. I was pleased to see a few survivors on our lavender this weekend, but this is a brand new worry!

bee buzzing on lavender stalk
Lavender loves dry heat, and bees love lavender, so there’s that…

Lack of flowering or fruiting

Those bees! They also help pollinate our ornamental plants and especially our vegetables. So, there’s one concern in heat. But I recently was reminded how heat also affects flowering and fruiting. It turns out that pollen loses its effectiveness in high heat. Even though we’ve hit the 100° mark before, I can’t recall it lasting for days and weeks since we’ve been growing tomatoes and other edibles in New Mexico. What’s more, drought lessens the chance that pollen can stick to a female flower.

tomatoes green on plant
These tomatoes got started before the heat wave, and I think the plant is doing all it can to keep them nourished.
Another plant is failing to produce. I'm hoping there's still a viable tomato behind each dried up bloom.
Another plant is failing to produce. I’m hoping there’s still a viable tomato behind each dried up bloom.

Wilt

This is the heat issue we best recognize – leaves wilting on a hot day. Plants “sweat” to cool themselves like we do. With transpiration, water travels up from the roots and to the leaves, where it evaporates through tiny pores under the leaves. So on a hot, dry day, the soil, roots, and entire plant dry out more quickly. Add some wind just for fun, and a plant can wilt or stress. Plants can take more water, but only up to a certain point. Some plants have plenty of moisture and experience what’s called “incipient wilt” during peak heat each day. If they recover by morning, the plant probably is getting plenty of water.

yellow squash leaves wilting in heat
The big leaves on our yellow squash tend to wilt each day, but the plant looks healthy when it cools.

Sunburn and sun scald

Plants can get sunburned. The sun can scorch leaves of plants that typically need a little more shade or lower temperatures. And many plants can burn on super-hot days. The sunburn often leads to brown spots or browning and dying of entire leaves. Sunburn of a few leaves shouldn’t be a problem, but a sign to shade or move a plant if possible. Sunscald is similar damage to bark in high temperatures.

When weeds and wildflowers wilt, it's just too hot and dry. We have some that also look burned up. Woohoo!
When weeds and wildflowers wilt, it’s just too hot and dry. We have some that also look burned up. Woohoo!

Entirely new or different insects

Aphids, which can be controlled organically, tend to love cool, moist weather. Every type of insect is different, but they’re cold-blooded creatures. Insects can’t internally regulate their temperatures, so they rely on what’s happening in their environment. I’m certain that both weeds and insects change each year depending on weather. Cabbage loopers and leaf miners like heat. Ants? Don’t get me started. And dreaded grasshoppers thrive in drought. When a plant already is stressed by heat or drought, it’s more vulnerable to insect damage or insect-borne diseases.

grasshopper in patio chair
Sure, grasshopper, pull up a chair. In fact, take the shady spot. I’d rather see you resting than eating on our plants.

Some plants adapt better to heat than others. However, young plants still might need more frequent watering in high heat. That’s the part that’s getting to me most. We have some new plants we put in the ground not long before the heat wave hit, and they’re struggling. We’ve even had to water a few xeric and waterwise plants that typically thrive with no water at all. It’s all part of the fun of gardening in the Southwest, I guess. See my previous post for tips on helping plants survive extreme heat.

10 Tips to Help Plants Survive Summer Heat

Even waterwise plants get stressed when exposed to high heat, dry air and wind. Many Southwestern plants can survive hot temperatures because they’re native to the low desert. But in some areas such as the mountains and high deserts, native plants are a little more winter hardy and a little less heat tolerant.

chocolate flower blooms
Chocolate flower (Berlandiera lyrata) blooms are perkiest in early morning but tend to wilt late in the day. No need to water or worry.

Even in the hottest Southwest and West climates, plants can need extra attention when temperatures soar. Here are 10 tips for helping plants survive the heat of summer.

Tip No. 1. Use drip irrigation.

You save water because it can’t evaporate as rapidly as it can if in the air, and the water seeps slowly down to the roots of a plant. This helps cool roots as well as hydrate them.

drip irrigation and straw on cucumber seedling
Drip irrigation is the only way to go for water savings and for keeping plants hydrated on hot days.

Tip No. 2. Use mulch.

Something as simple as straw spread out on the dirt helps keep air from rapidly evaporating water, but still allows oxygen to reach soil and roots. Piling the straw or other organic mulch two to three inches high helps even more.

straw mulch container tomato
Happy new tomato fruit with straw mulch in a container.

Tip No. 3. Try to get your plants established before summer heat ramps up.

Even heat-loving plants can wilt when temperatures soar. Still, recognize that wilting from sun can be temporary. The bigger the plant’s leaves, the more quickly the plant transpirates, which is the process of water evaporation through leaves. That’s why many succulents and xeric plants have small foliage. So don’t panic, but don’t completely discount it. Increase drip time on hot and windy days.

Tip No. 4. Water in the morning if at all possible.

This is a great water-saving strategy and helps prevent heat stress to plants. If the roots already have access to water, they can begin sending the water up through stems and leaves to keep the plant nourished. For most plants, regular, but spaced, deep watering always beats out frequent light watering (which leaves moisture close to the surface and can restrict root growth).

Tip No. 5. Check on your plants.

If you can’t check them during the day, do so as soon as you get home. It’s OK to water plants lightly in late afternoon to help cool them down.

xeric garden summer heat
Walking around your garden helps you spot heat stress and pest damage.

Tip No. 6. Use one plant as a benchmark.

For example, zucchini leaves are large, and if they’re wilting, you can prevent heat or drought damage to other plants nearby with a cool drink of water or some shade.

Tip No. 7. Shade plants.

New or damaged plants might need temporary shade to build up resistance to heat. Direct sun can burn leaves just like it can burn your skin. So make sure even an established plant is in the right location for sun and summer exposure and if not, try temporary shade.

cloth shade for plants.
It’s not pretty, but it’s clever. Tim built this removable shade out of landscape fabric, PVC and conduit.

Tip No. 8. Use containers.

Containers offer you the most opportunity to shade plants on hot days. Although soil in containers warms faster, containers also can cool more quickly. Most of all, it’s easy to move all but the largest into shade temporarily. You can mulch the top of the soil in a container, too.

containers on patio
Got containers? If you see a plant might be getting too hot, move it into afternoon shade. The white bucket in one container helped shade a new cherry tomato from sun and wind.

Tip No. 9. Avoid fertilizing plants during the heat of the day.

Plants should be perky and healthy before soaking up fertilizer. And the fertilizer needs to mix with plenty of water. It’s best to do this task before mid-day heat kicks in.

Tip No. 10. Control weeds.

Ha, there’s an impossible goal around here. And I know there are people who embrace weeds. I tolerate them only because I can’t keep up. But we’re really vigilant about keeping weeds off of or out from under plants. That’s especially true in the vegetable garden. Mulching can help control weeds.

field bindweed
Bindweed wraps around the base and stems of plants, weakening them. All weeds compete with garden plants for water.

Bonus tip.

Finally, if you keep potted plants, including cacti, inside during the winter, you need to protect them as they adapt to being outside. That’s true even for sun lovers. Harden the plant off if you can. If the plant is too heavy to bring in and out all day (or you have 30 of them, like we do), at least start it outside on a cooler, cloudier day.

Cacti under shade cloth
Succulents under the shade cloth. Yes, even some cacti can get too much sun. Containers allow these to survive winter inside and summer out in the heat.

Earth Day 2016: Five Green Gardening Tips

It’s Earth Day 2016! It’s hard to believe this movement started in 1970. Earth Day says “let’s get big stuff done for the planet.” I love that idea! But it’s also overwhelming. I mean, I have enough trouble taking care of myself while juggling work, family, and getting anything done to care for our four acres. But the only way to take big steps for the planet is if everyone takes a few small steps. Here are five tips for greener gardening today and all year long.

panorama of New Mexico xeric garden
If only I had a 360 camera. Mountains, sky, low-water plants, and passive solar living.

Have an empty spot to fill? Use what you have.

Sometimes a plant dies even with our best efforts, leaving an empty spot. Or maybe you’ve been studying an area of your yard all winter knowing it just needs something. Instead of buying a new plant, divide or move an existing one. Plenty of plants that spread divide and transplant easily. For example, Russian sage sends up runners that you can sometimes transplant. Our purple salvia created about five offshoots over winter, one below the garden in the grass. Tim dug up several and potted them; we even gave one to a friend. We also moved several plants. This is a great money saver (and sometimes plant saver) when areas of the garden become overgrown or one plant no longer gets the sun it should. We moved one of the three Apache plumes in our xeric garden to an area that helps screen off a little bit of our vegetable garden. Close enough to attract bees.

New Mexico rain barrel, reuse plant
Just behind the rain barrel (hint, hint) is a blue mist spirea. It did well there until we diverted some water when extending the patio (and added the barrel, which can overflow). It got too much water! So we split it up and moved it.
yarrow before moving
Yarrow is an herb, easy drought-tolerant plant and pollinator magnet.

Help beneficial insects.

Our lawn and garden attracts bees from late winter until the insects cluster tucked away in winter. The garden also attracts butterflies and hummingbirds. Moving the Apache plume, along with an offshoot yarrow and two divisions from our blue mist spirea, we just added a new hangout, inviting them to gather closer to our tomatoes and cucumbers!  We’ll add milkweed this year for the monarchs, and I can’t wait to see how that goes. We’re growing ladybugs, unintentionally. And I’m counting on them to keep aphids off the milkweed.

bee on blanketfower bloom
Annual Gaillardia plants reseed all over the garden. Bees and butterflies love them.

Avoid chemicals whenever possible.

Speaking of ladybugs and bees: insecticides kill these helpful insects along with the bad. There also is no need for chemical-laden herbicides in most cases. And I’m saying that knowing full well that half of our orchard is almost entirely covered by horehound. This member of the mint family does best in drought. I know that because if we try to hoe it up, we usually hit rock. I can’t win against a plant that grows from rocks and prefers dry conditions, especially around here. My Earth Day gift: Anyone who wants to make candy or cough syrup can come here and harvest all the horehound they want! As for care of vegetables and other plants you actually want in your landscape, paying attention to their sun exposure and watering needs helps prevent future problems. Enriching soil with compost is a slow, natural way to add nutrients. Compost tea is a gentle fertilizer.

horehound spreading
We mow and hoe, but the horehound thrives in dry conditions.

Grow food for your family or wildlife.

Growing food in the garden saves water. It sounds counterintuitive, but it’s not. I can control (within the limits of nature and horehound) the health of my edibles. And keeping them healthy can save water. Sure, they are not native to our area and require more water in the heat of summer than we could ever responsibly pour to an ornamental plant. But every tomato in the grocery store was watered, probably a with a lot more than I use. Even though water availability is regional, it also can vary. And it’s a shared, finite resource. A shrub with berries feeds birds. Fruit trees are a great example of planting a tree for shade or spring blooms with the added benefit of food. Those who don’t like the mess can choose dwarf fruit trees appropriate for their area. And no matter what anyone says, I think green bean, melon and cucumber plants are as pretty as most flowers!

cucumber blossom
Fully open cucumber blossom. I think it’s an attractive plant, too.
old pear tree trunk
This old pear tree is a stunner when it blooms. The trunk looks like it could talk.

Water responsibly, no matter where you live.

Back to water, because that is always a concern on our place and in most of the Southwest. As I said, it’s a shared and finite resource. If I use too much from our well (or from city supply), I affect the water table, the saturated, upper part of groundwater where rain has soaked through soil. Groundwater provides nearly 40 percent of water for cities and counties, and drinking water for most rural people. It’s everybody’s job to do their part in the home and garden, no matter where they live. Use of drip irrigation, watching and caring for plants sustainably, watering early in the day and using automatic timers to control sprinklers or smartphone timers to remember to turn off the hose are small but important steps every gardener can take.

snorkeling in clear water
And this is why Earth Day matters most. For my daughter, her fiance and all future generations. Photo by Dave Higgins.

Happy Earth Day!

Watering Container Plants

Container gardening is the mainstay of apartment and small-home gardeners. But even with four acres to play on, we plant plenty of succulents, herbs, vegetables and a few ornamentas in containers. For gardeners with more space, containers add convenience for kitchen garden edibles, and for moving plants that spend winter indoors. There are plenty of reasons to choose containers and plenty of ways to manage water use with container-grown plants.

nasturtiums rustic container
Why not repurpose an old washtub when you’ve got nasturtium seeds begging for a sunny spot?

The right plant

Annuals are great choices for container gardening, since you don’t ever have to repot the plant. And since xeric perennials need little water once established, having some annuals in containers or a small bed is a perfect splurge, especially if the annuals reseed.

It’s true that container plants need more frequent watering, so low-water herbs and other xeric plants make the best choices. But you can grow edibles and any small plant in a container. In my mind, the water for edibles produces food. And as long as I water responsibly, I’m OK with using a container and hand watering lettuce and tomatoes instead of using drip irrigation in the ground.

chile pepper in metal container
This green chile didn’t do well in such a small container, but it was fun to place on the patio. And we got a few peppers from it.

When creating arrangements, place plants with similar sun and water needs together. If you really want a centerpiece plant that uses a little more water, find a way to contain it by placing it in a plastic nursery pot (probably a few inches larger than the one it came in) inside a larger decorative one. Underplanting with flowers can disguise the trick that lets you focus a little extra water on one plant without overwatering others.

Selecting containers

I love to repurpose and use fun and funky containers when I can, but I typically use well-designed plastic or glazed containers for edibles. Plastic containers usually use the least amount of water, and glazed containers slightly more. We have lots of clay containers too, but we reserve most of those for cacti and succulents. Clay dries out quickly, so it’s best reserved for the lowest water users. And although photos always show containers filled to the edges with plants, consider mature growth even for summer annuals. For example, petunias multiply! It’s so fun to create a mini-garden scene with a big grouping of containers, especially if you have the space and money. I have a small grouping of more attractive and slightly lush containers in the front of our home, but the ones in the back are for function as much as form.

Cacti and succulents do well in clay pots and most containers.
Cacti and succulents do well in clay pots and most containers.

Prep the container

It’s important to use good soil for container plants and not extra dirt from the hole you just dug for your rose bush! Placing it in a pot just creates a big, clay petri dish for disease, insects and weeds to grow in. Soil also tends to compact more easily in a container. And the nutrients available for flower and fruit production are limited compared with the big, open ground.

Japanese maple in container
I love the combination of Japanese maple, bamboo and the container.

You can add small stones along the bottom to help with drainage and reduce watering by using a potting mix with polymer crystals that hold some moisture and then release it. Or add something more sustainable such as Growstones. Just don’t use a rich mix that retains moisture for cacti or other plants that need well-drained soil.

carrots growing in trough
It takes a lot of soil to fill a trough. Look for local compost and garden soil bulk suppliers.

When choosing organic potting mixes for edibles or just because, use some caution. Many potting mixes labeled organic are so similar to compost that they contain plenty of nutrients, but are too dense to use alone. A lighter mix helps air and water reach roots. Look for organic fillers such as coco husks. And don’t overfill the pot; you need a few inches at the top for water to sit while it drains down. If you get the soil level too high, water can run out the top of the container.

Water slowly

The key to healthy container plants and water savings is to water slowly. Flooding a container plant washes out important soil nutrients. Placing a small coffee filter over the drainage hole allows water through but stops soil and  nutrients from washing out the bottom. I try to pour slowly from my pail and then return a few minutes later for a second slow watering as I make my way from container to container. We use rain water as much as possible for container watering.

If you have a drip system with good pressure, you can have it set up to water containers, especially grouped one. You could use an olla, which is a clay bottle you bury in the container that slowly seeps water and can be refilled. To me, one of the best qualities of containers is that you can move them to meet shifting sun requirements or whims. And when a plant begins to wilt, it might not need more water – it just may need less sun.

Healthy looking native plants outside the Native Seeds/Search store in Tucson, Ariz.
Healthy looking native plants outside the Native Seeds/Search store in Tucson, Ariz.

I’m not big on fertilizing because it can lead to too much leaf and branch growth (and not enough to fruit and flowers) or burn plants if done too soon or incorrectly. I’d rather keep improving soil in beds so plants get most of their nutrition each year from natural ingredients. But container plants can need a little extra help. Compost tea or a light application of a product like Happy Frog every few weeks can support container plants.

I’m hoping to order some new containers this year locally or from Arizona Pottery. I’ll update when I can.

Conserving Lawn and Garden Water: Seven Solutions

Xeriscaping isn’t for everyone; most plants native to arid zones do poorly if grown in a humid, rainy region. A plant adapted to 14 inches of rain a year will go soggy or leggy, and likely die, if it soaks up nearly 60 inches of annual rain. And vice versa. A Southwest gardener might love tropical plants, but the plants would need loads of water and attention here. Our relative humidity has dropped to the single digits lately.

xeric plants rock garden nm
Xeric plants can pop with blooms and come in many colors.

I’ve written plenty about choosing native or appropriate plants, and that’s still the most critical strategy for the combination of plant health, water savings and garden budget. Our zone 6B might have similar temperatures to zone 6B in West Virginia, but the state averages 44 inches of rainfall a year vs. 14 inches in New Mexico. If a 40 ft. x 70 ft. roof can gather more than 1,740 gallons of water from one inch of rain, imagine how many extra gallons of water fall on a plant where 40 more inches of rain fall than it’s used to receiving.

summer monsoon
We get some rain (and hail), but most of it falls during the summer monsoon season.

So, tip number one is to choose plants suitable for zone, exposure and precipitation. That’s a key to successful gardening no matter where you live.

Give in just a little to whims. If you want to indulge your love for tropical plants but you live in the arid Southwest, choose only one or two and place them in containers. Likewise, a succulent likely will survive better in the Southeast if protected from rain. You can protect it with containers that you move under shelter or indoors, or try the French solution, shown here by Debra Lee Baldwin.

Place plants with similar water needs near one another, especially if you use automatic sprinklers or drip systems in the lawn and beds. You can regulate zones or emitters, but plant roots seek water, and studies have shown that roots can even detect the sound of running water. Anyone who has had to repair pipes damaged by water-loving willow roots or the more xeric locust tree knows how this works!

drip irrigation
A low drip saves water and helps plants.

Use drip irrigation in vegetable gardens or ornamental beds. It’s the most efficient way to water. And slow drip is better for plants because the water soaks in gradually without washing away nutrients. Water containers as slowly as you can, or water half as much as each plant needs, then circle back for a second dose. It takes a little longer but avoids water (and soil nutrients) rushing out the bottom of the container. If rain in one area mostly falls during certain months, turn off or completely reprogram the sprinklers and drip controls. Or look for one that senses rainfall and shuts down watering accordingly.

Our potted tropical canna gets to live outside in the summer. But tomatoes also make great container plants.
Our potted tropical canna gets to live outside in the summer. Tomatoes also make great container plants. The canna needs extra water, but the tomato is all about consistent moisture.

Prepare soil. Healthy soil makes for a healthy plant and supports drainage. If it’s too sandy, water rushes through, and little soaks into roots. If it’s too clay-like or compacted, water pools on or just under the ground. Likewise, some plants only do well in a particular soil type. Amending soil can be tough, so choosing a plant that can handle current soil conditions is a great idea to save water and money. With healthy soil, you’re more likely to have healthy plants, and not assume one that looks bad just needs more water!

soil prep for herbs
Lots of compost enriches this soil for herbs, but the xeric area above remains as is, which is mostly rocky.

Mulch. Mulching cools roots and slows evaporation. Organic mulches eventually break down and improve soil. As with plants, it’s best to get some local advice on the best mulches for your area and conditions.

Switch to plants with purpose. Growing edible plants saves or exchanges water somewhere down the line when you don’t have to purchase the food at a store. You can fill your garden with green, but harvest herbs and vegetables at the same time. Or grow plants that double as resources for crafts, gifts and cut arrangements.

basil nasturtium
California garden with gorgeous basil and nasturtiums, which have edible flowers.

Conserving water might be more critical in the Southwest, but even gardeners in states like Alabama and West Virginia should keep water savings in mind. Local water utilities spend less in the long run when they don’t have to process as much potable drinking water, which is what most homeowners use outside. Weather patterns are unpredictable and climate disruption affects plant cycles and water availability.  Some areas receive more rain in spring and less during hot summers; taking steps to lessen the amount of irrigation needed to help plants through hot, dry periods makes for good sense and citizenship.

I realize some plants can get too much water, but that’s all the more reason to watch irrigation. And the best way to check plants and soil is to stroll through the garden, stopping to smell some flowers along the way, of course!

 

 

Plant Select 2016: Waterwise Grass and Groundcovers

I get so excited when I see the Plant Select press release in my messages each spring. I love any new plant introduction or award winner, but Plant Select focuses on plants that adapt to – and thrive in – the dry, wild conditions of the intermountain regions and high plains. Gardeners can be confident that their selections will work in much of New Mexico, Arizona, Colorado and other western states. This year, Plant Select announced two new groundcovers, and selected a drought-tolerant turf and groundcover. Anyone ready to switch out a high-water lawn should take note of these choices:

new ice plant orange flowers
Red Mountain Flame ice plant. All the pluses of an evergreen ice plant, plus a new orange tone! Image courtesy of Plant Select and David Salman.

Red Mountain Flame ice plant (Delosperma ‘PWWG02S’). An ice plant with deep orange to red flowers! Ice plants came to the U.S. from South Africa. The plants use little to moderate water once established, yet they provide gorgeous, evergreen groundcover for the xeric garden. One reason is that they spread quickly. But ice plants won’t get invasive. When ours have spread too far, we’ve even transplanted some of the extra plant to another area of the garden with success. They’re usually yellow or pale pink to purple. I’m thrilled to have a new ice plant color choice for rock gardens and other beds. It’s also perfect that New Mexico’s own David Salman of Waterwise Gardening produced the Red Mountain Flame seedlings. Grow ice plant in zones 4 through 9. Red Mountain Flame needs a mix of sun and shade.

Alan's Apricot ice plant
Alan’s Apricot ice plant boasts larger, color-changing blooms. Image courtesy of Plant Select and Alan Tower.

Alan’s Apricot ice plant (Delosperma ‘Alan’s Apricot’PPAF). The apricot-colored blooms of this new introduction are similar in color to existing ice plants, but larger. It also changes color to a pinker hue and then back again. Ice plants turn heads in summer when they fill with blooms on the low foliage. I can only imagine how Alan’s Apricot’s two-inch blooms will look in mid-summer. The larger, showy flowers also will shine in a container or the landscape as blooms begin to open or close each season. The ice plant was developed by Alan Tower of Spokane, Wash. Also for zones 4 through 9, a variety of soils, and a mix of sun and shade.

Moroccan pincushion
The Moroccan pincushion is a great groundcover selection for rock gardens. Courtesy of Pat Hayward at Plant Select.

Moroccan pinchusion flower (Pterocephalus depressus). The Moroccan pincushion has similar foliage and an inch or so more height than ice plants. The pincushion flowers are light pink to rose in color and leave silvery seed heads after fading. It’s also evergreen, offering winter foliage in zones 4 through 8. Add Moroccan pincushion to a rock garden, raised bed or large container in full sun. The plant needs little to no water once established and should have soil that drains well.

dog tuff grass
Dogs can run on and water drought-tolerant DOG TUFF without damaging the grass. Image from Plant Select and Kelly Grummons.

DOG TUFF grass (Cynodon ‘PWIN04S’).  Why have no lawn at all when you can have areas of turf for kids and pets, along with the look and cooling effects of grass? I’m all for removing some lawn, even more if you have a high-water grass. But I’ll never stop trying to convince people to leave a little grass. DOG TUFF lets homeowners have the best of both worlds: saving water and keeping a lawn. DOG TUFF has an extra quality that might have influenced Plant Select’s choice. Like the name says, it’s tough, holding up to foot traffic even in a xeric lawn. It also holds up to your dog’s help with “watering.” The grass comes in plugs for easier spread and planting. DOG TUFF needs more water the first year, but once established, the warm season grass should return in late spring for all-summer coverage in zones 5 through 10. Learn more about planting and caring for DOG TUFF here.

Plant Select is located in Ft. Collins, Colo., where its staff puts plants to work in test gardens to see how they do with little water. Plant Select also evaluates plants for adaptability, durability and ease of care. They also consider how attractive the plant is in the garden and whether it’s wildlife friendly.

Calculate How Much Rainwater You Can Collect

Harvesting rainwater makes perfect sense, and we learned more about the process at a terrific workshop we attended at the NM Organic Farming Conference in Albuquerque last week. From neighboring Texas, Billy Kniffen is the water resource specialist for Texas A&M University.

Kniffen explained that catching and using rainwater is not a new concept; early settlers in the West captured water. Interest is increasing today, at least among homeowners and gardeners who live in states that allow rain harvesting. We’ve used one or more rain barrels to capture roof water for years, and hope to someday acquire a large cistern. As Kniffen said, “the first rain barrel is the ‘gateway drug’ to rainwater harvesting.”

rain barrel shed
This was actually our third rain barrel, located near our vegetable garden. I couldn’t stand to watch the water pour off that shed roof without catching at least some of it.

Getting Started Is Easy

I believe more people would harvest rainwater if they realized it’s not as complex a process as it seems. For simple gardening use, a few rain barrels or a cistern with pressure can irrigate ornamental plants. If you want to water edible plants, you have to take a few more steps; it’s recommended that you add features such as first flush equipment (which directs the first flush from your gutters away from the barrel to prevent nasty debri from entering the container) and filters. A prefilter also keeps leaves and debris out; you just have to clean it from time to time. You also can disinfect your rain water with chlorine or ultraviolet light.

filter lid on rain barrel
Inexpensive, smaller barrels have crude filters to stop debris. A larger system needs a more sophisticated filter.

Calculating Collection

A house that has a roof of 1,000 square feet can yield 600 gallons of water from just one inch of rainfall. For me, watching the small barrels fill and then overflow feels like a waste. In our case, water that runs from the house eventually refills our water table – and therefore our well. But in urban areas, water runoff fills streets and gutters, and often is wasted. Texas A&M Extension has made it easier to calculate the amount of rain you can collect from your home or shed roof.

rain collection system model
Here’s the demo system Kniffen brought to our workshop. It’s simpler than it looks!

Here’s a simple calculator for catchment area courtesy of the college. There’s also a link here to a Microsoft Excel spreadsheet (under Resources) with the formulas already included. HarvestingRainWater.com also has a simple calculator. Texas residents, or those who can easily compare their annual rainfall to one of the included Texas towns, can input the information and receive monthly flow rates and required cistern sizes to catch as much rain as possible. Finally, the school also publishes a manual all about rainwater harvesting.

gutter on shed
We had to add a gutter to the shed roof to collect the water. It was simple and worth it.

Kniffen and his wife run their home solely off collected rainwater from their home and a shed. I don’t believe we have the money to collect all water and make it potable, but it’s always on the wish list. Any attempts to save and use rainwater can help preserve water for future years. I hope these tools make it a little easier for anyone considering rain harvesting to get started.

The Dirt on Saving Water in the Garden: Good Soil

Gardeners can take many steps to save water, such as saving rain water and using drip irrigation. But one of the most crucial steps lies beneath our feet, in the soil that protects and nourishes roots and controls water drainage and aeration.

black sand beach Maui
Black sand in Maui along Hana Highway. The black sand is made from lava rock.

What you can’t see: soil microbes

Tiny microbes feed soil and plants, relying largely on humus, the rich organic matter that results from decay of natural materials. When conditions are right, insects, earthworms and microorganisms in healthy soil create humus. Organic matter in the soil ensures that microbes thrive and the soil drains as it should. And when a plant is otherwise healthy, it’s less vulnerable to diseases and can likely survive with less water. In Master Gardener training, I learned that New Mexico soils have organic matter of 20 percent or lower on average. At our place, rocks take up 90 percent of the soil (slight exaggeration). We located our vegetable garden in an area that used to be part of an apple orchard and that’s near the river. The soil is much better than near the house, likely because of organic matter working its way into the soil over the years.

xeric rock garden
Got rocks? We’re certain the rock garden walls and borders were made with rocks excavated on our land! Many of the native and xeric plants have adapted to soil conditions.

Xeric plants and soil drainage

The thing is, many xeric plants are more affected by soil that remains wet than by lack of water. Lavender comes to mind; wet feet can cause root rot. Add a sudden drop in temperature to the dampness and lavender plants are at risk of dying. I’m seriously worried about ours after 18 inches of snow. Plant care instructions for nearly all xeric plants read “place in well-draining soil” because too much water in the soil suffocates a plant’s roots. Sand dries too quickly, but clay and compacted soils fail to drain.

Lavender does better with well-draining soil and less water.
Lavender does better with well-draining soil and less water.

Plants use valuable energy to pull moisture from soil. When they have to work harder to access water in soil, plants become stressed and wilt. If your soil drains quickly, you have to water more often and less deeply. Loam is the name used for balanced soil that has a fairly even mix of sand, clay and silt. As mentioned, clay soils hold too much water. Amending either extreme (sand or clay) with organic matter helps plants access the appropriate amount of water needed with less stress. Instead of adding sand or clay to balance soil, gardeners should use organic matter to gradually improve soil health and function.

This soil at the entrance to our vegetable garden is compacted foot traffic. Notice how water from snow melt stands in the soil.
This soil at the entrance to our vegetable garden is compacted from foot traffic. Notice how water from snow melt stands in the soil.
Only a few feet away is this raised bed with organic matter added. No standing water under the same conditions; the water is working its way down through the soil.
Only a few feet away is this raised bed with organic matter added. No standing water under the same conditions; the water is working its way down through the soil (and rocks).

Here are a few tips for ensuring your plants’ soil is healthy, providing nutrients, water drainage and oxygen to roots:

Add organic matter. The type of matter you add is more specific to your soil’s pH and other factors. But most natural organic amendments, such as manure or green manure, can help.  Also called cover crops, green manure is the purposeful planting in fall and winter of crops that restore soil nitrogen and organic matter used up by summer plants. When using animal manure, add it to compost or make sure it’s cooked completely; don’t add fresh manure to growing plants.

You can see the difference in the color and texture of the mushroom compost that sits on top of the summer vegetable bed. The soil needs some help.
You can see the difference in the color and texture of the mushroom compost that sits on top of the summer vegetable bed. The soil needs organic matter from the compost and some broken-up plant residue.

Properly handle plant residue. Although some schools of thought are in favor of letting spent plant material stay on the ground to decay and provide organic matter, gardeners should use caution. Insects overwinter in plant residue on the ground (good if you want monarchs, but you can’t really go around selecting which insects get to take up residence). And it’s never a good idea to use diseased plant material. We kept some healthy plant material, but anything that looks funky goes into compost bins or garbage. We don’t mess with “wilder” areas around the property.

An unripe pear and leaf material remain under a large, old pear tree. They'll compost and improve soil, but also attract ants and other insects.
An unripe pear and leaf material remain under a large, old pear tree. They’ll compost and improve soil, but also attract ants and other insects.

Use organic mulches. Adding mulch around (but not against) the base of the plant helps slow water evaporation from the soil. Organic mulches eventually break down, improving soil make-up.

Here at the Los Angeles County Arboretum and Botanic Garden, landscapers have added mulch around many beds, including blue fescue.
At the Los Angeles County Arboretum and Botanic Garden, landscapers have added mulch around around many plants, including blue fescue.
Cacti at the Arizona-Sonora Desert Museum in Tucson, Ariz. need no mulch!
Cacti at the Arizona-Sonora Desert Museum in Tucson, Ariz. need no mulch!

Rotate crops and use cover crops. In vegetable and herb gardening, move annual crops around so that the soil nutrients get a break. Families of plants differ in how they use soil nutrients.

Stop tilling. Rototilling, the traditional farm method, burns off carbon and adds to weed emergence. It also breaks soil up into smaller particles, which makes it less permeable for air and water. Repeated tilling leads to loose top soil. Heard about the Dust Bowl? Work added organic matter into the top few inches only, or let it sit on top of soil.

When in doubt, test your soil to determine how much of it is sand, clay or loam. You can perform your own home test pretty easily using a mason jar, as described on page 11 of this publication from the San Diego County Water Authority.

 

Save Water by Growing Food: How to Add Edibles to a Low-water Garden

Growing edibles can be a smart xeric strategy, especially for anyone looking to begin a garden or use less water in the lawn and garden. Many edibles are attractive and some are evergreen. If you live in an arid zone, applying more water to edibles than to ornamental plants is the right thing to do. Here are a few strategies for making your lawn and garden attractive while saving water and helping to feed your family.

container edibles
Tomato and rosemary make gorgeous edible container plants, especially interspersed with herbs and flowering plants.

Grow perennial herbs and vegetables

Luckily, several delicious and useful perennial herbs require little water. My favorites are rosemary, sage, lavender and thyme. All of these plants thrive in our xeric garden at zone 6B, and many are hardy to even colder temperatures. Providing well-drained soil helps these herbs survive; some of the only diseases that attack them are related to prolonged wet roots or poor air circulation around wet leaves. Other useful perennial herbs for the xeric garden include bee balm, yarrow and oregano.

Lavender is one of the prettiest xeric herbs. Use it in recipes, to make gifts, or to attract pollinators to your garden.
Lavender is one of the prettiest xeric herbs. Use it in recipes, to make gifts, or to attract pollinators to your garden.

Once you’ve mastered a successful season growing food, consider a perennial vegetable such as asparagus. One plant can survive for more than a decade. Growing asparagus requires some patience until the plant produces and a commitment, but harvesting fresh asparagus for several years would be worth it. Although the vegetable requires more water than some for the first few years, you’re likely to use less water over the life of the plant than you would by planting a crop of zucchini or other vegetable year after year. Asparagus is hardy in zones 3 to 8. Some spears showed up along our ditch bank last year. They were leggy, but the plants have survived several winters with no irrigation or other effort on part, since we didn’t know about them. Here’s an article from Gardener’s Supply Company on how to grow asparagus.

This apricot looks beautiful all year long and shades parts of the house, patio and garden, even though frost has kept it from producing fruit for a few years.
This apricot looks beautiful all year long and shades parts of the house, patio and garden, even though frost has kept it from producing fruit for a few years.

Shade with trees that produce food

Shade is a must for lawns in hot, dry climates. If you’re going to plant a shade tree, why not choose one that produces food? I believe that fruit trees get a bad rap as being “messy.” It takes less time to harvest from the trees or pick up dropped fruit every few days than it takes some of us to make a grocery trip! Enjoy the shade of an apricot or apple tree and delicious, fresh fruit in summer, depending on the year’s frost. Fruit trees also have beautiful spring color and attract pollinators. Some nut trees thrive in warm climates.

We had to climb ladders and compete with birds for our tart cherries this summer, but they were worth it.
We had to climb ladders and compete with birds for our tart cherries this summer, but they were worth it.

Dwarf fruit trees provide less shade, but use less water and space and produce a more reasonable amount of fruit. Busy working parents likely will appreciate that dwarf fruit trees entail less work than full-sized ones in an abundant year. Dwarf trees require less climbing and pruning, and often produce fruit earlier than their larger counterparts. A single dwarf tree that requires no companion for pollination can add a little shade, color and interest to a xeric lawn or garden. Just be sure to choose a variety hardy for your zone. Many dwarf pears, plums and apples are hardy to zone 5; Stark Bro’s helps you choose a dwarf variety based on your zone. Mulching around the tree can reduce water needs.

Use shade for other edibles

Trees provide shade for people and plants. Take advantage of shade to grow edible crops under trees, shrubs or other vegetables. Many herbs and vegetables tolerate partial shade or grow best during cooler weather. Planting basil where it gets afternoon shade can help the plant thrive and use less water. Just be sure to estimate where the shade will be come the height of summer, not where it is when you plant.

These containers grew short-season tomatoes, basil and marigolds. We could move them to adjust to shade, then back into more sun as late summer shadows shifted.
These containers grew short-season tomatoes, basil and marigolds. We could move them to adjust to shade, then back into more sun as late summer shadows shifted.

Planting edibles in containers is a smart water choice and can give the gardener more flexibility in controlling sun exposure. I planted several tomatoes in containers and moved the pots slightly as summer became hotter, giving them plenty of sun, but afternoon shade on our patio. Of course, you need a properly sized container for the plant you choose. Grape and cherry tomatoes need a little less space than full-sized varieties. You can place containers in the shade of trees, right in the garden, to complement your garden’s design.

Choose cool-season crops

Providing shade extends the season of crops that grow better in cooler temperatures. Choosing some cool-season crops also can save water because these edibles produce in early spring or late fall, using less water than those grown in hot summer sun. We’ve used shade to grow lettuce mixes and spinach. Again, using containers for these crops allows you to easily move the container when summer sun or drought stress the plants. And containers help you grow edibles close to your kitchen for more months of the year.

spinach in metal container
Lettuce and spinach prefer cooler temperatures; our apricot provided afternoon shade for a spinach container.

Although you might not think you’re saving water when soaking tomatoes, consider the amount of water that goes into tomatoes you buy at the store, along with the energy used to transport them. Most of all, take a bite of a tomato right from the vine and you’ll quickly lose your taste for any store-bought fruit.

Tomatoes, green beans and cucumbers fresh from our kitchen garden.
Tomatoes, green beans and cucumbers fresh from our kitchen garden.

10 Reminders for Waterwise Gardening

Although the drought has eased in New Mexico and some areas of the Southwest, it’s still serious in many regions. Plus, there are plenty of reasons to save water in the yard, garden or farm all year long, regardless of your region’s current drought status.

Native plants adapt. These grow from the sand along White Sands Missile Range near Las Cruces, N.M.
Native plants adapt. These grow from the sand along White Sands Missile Range near Las Cruces, N.M.

No matter where you live, the foremost reason to adhere to low-water gardening designs and principles is to conserve water, which is the right thing to do for this and future generations. I doubt homeowners in California, many of whom typically enjoy steady rainfall of 18 or more inches a year, were concerned about drought when they had their yards designed decades ago. In fact, the 1913 completion of the Los Angeles Aqueduct likely marked the beginning of the phenomenon that occurs when too many residents are concentrated in a geographic area, especially one not conducive to urbanization.

The aqueduct and population are only part of the problem in California or in any region short on water. The Environmental Protection Agency estimates that every American uses about 320 gallons of water a day. Nearly 30 percent of home use flows outdoors, including on lawns. All-told, home landscape irrigation accounts for some 9 billion gallons of water a day around the country.

If you’ve read past blog posts, you know that I plead for a measured and appropriate response, one that if taken before severe drought strikes can prevent community, and eventually global, water crises. That approach includes native or xeric landscape design, not the destruction of all living plant material in a lawn. As I’ve said before, replacing grass with gravel doesn’t necessarily save water or energy.

native grass acreage
Our native grass (and weed) lawn receives no water except rain.

For a 2015 recap and 2016 garden prep reminder, here are the 10 easiest ways to save water in your lawn and garden:

1. Convert some turf to gravel if you like, using oasis zones and smart xeriscape design principles. Involve a landscaping professional if the job is big or the concept overwhelms you.

2. Convert high-water turf to a native, low-water grass. The best choices for high desert areas are Blue grama (Boutleoua gracilis) and Buffalo grass (Buchloë dactyloides). A new hybrid called Dog Tuff (Cynodon hybrid) also comes in plugs for quicker spread.

3. Water wisely, cutting back in winter and irrigating only in the cool of the morning during summer. Use drip irrigation instead of spray or sprinklers when possible. Add mulch around plant beds.

garden Drip tape in vegetable bed
Drip irrigation saves water and improves plant health for edibles or ornamentals.

4. Look for signs of water waste, such as runoff. Create a dry-river bed, bioswale or terrace to capture water and place plants with higher water needs in swales or at the bottom of inclines. Well around plants that need a little more water.

5. Remember that even low-water or xeric plants need extra water the first year; if the plant doesn’t make it because it dries out, you’ve wasted whatever water you used to irrigate plus the cost of the plant.

6. Choose perennials over annuals. Every time you plant annuals, you must water them extra to help them get established for the season. Growing more perennials and letting native annuals and wildflowers go to seed is a better strategy; leave one small bed or container arrangement only for annuals each year.

This pretty summer scene includes nothing but perennials, volunteer annuals and a few edibles in containers.
This pretty summer scene includes nothing but perennials, volunteer annuals and a few edibles in containers.

7. Grow edibles in your lawn or landscape. If you don’t want the look of a full-blown kitchen garden from the curb, place perennial herbs or low-water plants with berries for your family or birds in the most visible areas of the landscape.

8. Make smart use of containers and raised beds. Containers and raised beds use less water than the ground. Just be careful to water slowly. If water pours out the bottom of the pot, you’ve probably given more than the plant needs, and if you water rapidly, you can wash nutrients from the pot’s soil mix.

9. Check and improve the soil. It’s easy to ensure good soil and drainage in containers, but less so in the lawn. Even without a soil test, a gardener can see when the ground around a plant doesn’t drain well; that can be the death of many xeric plants. Adding organic matter and loosening the soil (but not tilling) can help build soil health over time.

Here's Tim loosening compacted soil in our vegetable garden. We worked in more compost that should break down this winter.
Here’s Tim loosening compacted soil in our vegetable garden. We worked in more compost that should break down this winter.

10. Capture and use rain water. If you don’t want to water edibles this way, at least catch rain from your roof to water your ornamentals. It might seem like one 50-gallon barrel isn’t enough, but as with all waterwise gardening, every little bit helps.

Deer graze the native grass that receives only nature's water, and a rain barrel provides water for containers.
Deer graze the native grass that receives only nature’s water, and a rain barrel provides water for containers.

Search or browse past posts in the Archive or check my Resources page if you want to learn more about low-water gardening strategies. And here’s to 2016!