Fall Gardening Project: Dry River Bed

In the arid Southwest, most plants don’t like an abundance of rainfall. Xeric plants such as lavender or rosemary can be damaged or die from too much moisture in the crown or roots. Sometimes, the location a homeowner places a plant affects watering and alters the plant’s ability to thrive as as it should for  the zone in which the gardener lives.

dry river bed
Dry river bed in summer, with blanket flower in foreground and blue mist spirea in back right. The spirea was getting too much water before we began.

Other times, conditions change. That’s what happened in an area near the foundation of our home when we expanded our back patio. We found that excess water from the patio and rain barrel near the edge redirected water during rains. During monsoon season, a blue mist spirea (Cayopteris) and cotoneaster began to show signs of overwatering.

DIY dry river bed
A before shot with Buster waiting in our high-traffic area of grass. The spirea is left foreground and the cotoneaster behind it.
dry river bed
We enlarged our patio and added a few rain barrels. This one was flooding the ground near it when it overflowed. The swamp milkweed we added likes the water.

We needed to divert some water away from the two bushes and recognized the importance of either collecting or directing rainfall. We couldn’t afford a large rain cistern, but we had one natural resource in abundance—rocks. So we built a dry river bed, also called a dry creek bed or dry stream. The project was a way to change up the landscape and divert extra water down to our lawn.

DIY dry river bed
We moved the blue mist spirea up onto a berm built with extra dirt — from another DIY project.

Step 1: Move plants

The first step in our project was to move the plants. We divided the spirea and kept the largest portion to replant; we transplanted two smaller sections on a ditch bank back in our orchard. We ended up removing the cotoneaster, which was beginning to overgrow a path we us regularly and had large areas of rusted, dying foliage.

DIY dry river be and added a Karl Foerster grass.
Our first replacement cotoneaster did not make it. We moved a cactus and penstemon to the new hill as well.

Step 2: Design hills and valleys; test

We next built up a small hill or berm as a new spot for the blue mist spirea and a new cotoneaster bush. This would allow us to control the plants’ watering better. We dug and scraped a river-like trough to help water drain down and toward the grass. It didn’t take much depth to get water from the patio to the grassy area below. Getting the depth and flow right took some trial and error with a garden hose to simulate the rain and made a few adjustments where water backed up.

Testing the flow while we could still lift the fabric if needed.

Step 3: Add rocks

We already had a pile or two of rocks we’ve dug up. And there is no shortage around here. The first step was to cut and lay down black weed barrier, followed by large rocks along the top and side of the dry river to hold the fabric, direct water and add a decorative, but natural effect. This was followed by addition of medium and smaller rocks. We gathered the small rocks throughout fall and winter, sometimes a few at a time, to fill in.

rock river bed
Rocks are much easier to come by around here than water. We lined the sides and bottom with rocks from our property. The large piece of flagstone is a step over the water that runs from the low side of the patio.

Step 4: Plant!

All our hard work was rewarded with a new area for planting. We had the two bushes, and moved a small pine leaf penstemon to a lower part of the berm. We purchased several grasses, some perennials and a few annuals to fill in. Then we got lucky and had a volunteer blanket flower crop up in just the right spot. We stopped the rock design a foot or more from the house in most spots and used pecan mulch around those plants. Here’s why: Rocks reflect sun and heat and my office window is right above the dry river bed area.

Mondo grass
We hope these mondo grasses will grow and spread to cool the wall a little. The mulch is pecan bark. And the new cotoneaster is small but healthy.

Lessons learned:

Pulling out the large cotoneaster and adding rocks has intensified the heat in my office. I know that will ease once the plants grow to maturity. And the heat might be welcome on a cloudy January day. We also lost the first cotoneaster planted. It could have been any of a number of causes, but we likely made a common mistake: not watering enough. I was so concerned with keeping this plant from getting too much water that I failed to account for how much would drain away from its roots and the immaturity of the plant. Our second attempt is going well. It’s also easy to change the flow of water just by placing a rock or two in a certain way. So we check the flow when it rains to look for pooling of water.

We transplanted some grass into the walkway and added two pieces of flagstone.

Overall, we were pleased with the look and function of the dry river bed. The native grass below it turned green earlier than normal and we stopped problems from mud and overwatering of bushes in the area. This is an easy and inexpensive garden DIY project!

 

Reviewing Garden Watering Systems

No matter where the current drought monitor stands, New Mexicans and other Southwest gardeners know that water is precious. Luckily, plenty of native plants have adapted to the dry conditions of desert and intermountain regions of the Southwest.

 

xeric garden color
Native plants and volunteer annuals add color to a xeric garden.

Still, gardening responsibly anywhere demands attention to water use and waste. And people who want to grow food in their yards or on their patios can save water and money with sensible, waterwise strategies.

The good news is that the home and garden market keeps pumping out new tools to help gardeners conserve water but enjoy their landscapes. I’ve recently reviewed two products for Gardening Products Review. One of the products combines solar technology with rain or faucet water to support slow drip systems in areas of the garden.

rain barrel watering system
Combining a solar-powered pump with a rain barrel is a brilliant idea.

The other product from a small startup company helps you water deeply near the roots of plants using a simple garden hose.  Up next: I’m testing a cloud-based system to control watering from your faucet.

watering system with hose
Adding some color from annuals, especially these snapdragons we grew from seed, is more water efficient and cost effective with drip watering. Adding some mulch would help retain the water and hide the hose.

Check out these watering product reviews, along with lots of other reviews from fellow garden writers at Gardening Products Review’s website. And plan now for next spring’s waterwise plantings.

5 Ways Organic Growing Methods Save Water

Growing with organic methods is smart for lots of reasons, both personal and environmental. Although there are plenty of strategies gardeners and homeowners can use to save water with ornamentals, such as planting native and xeric plants, it’s a little tougher with vegetable gardening.

Tomatoes and water
These yellow cherry tomatoes soaked up a summer rain from their container filled with organic soil and compost.

Tomatoes, for example, need consistent watering! But growing tomatoes organically can conserve water. Here are five ways how:

  1. Organic soil retains water better. Anyone can improve their soil’s water retention by up to 5 percent by adding organic matter. It also helps to avoid use of chemicals and pesticides. Using pesticides and chemical fertilizers in gardens can throw off the natural balance of the soil, making it less able to retain moisture around plant roots and making fewer nutrients available for plants. On the contrary, planting cover crops in the fall and use of compost or other organic matter help restore valuable soil nutrients. Organic matter also helps soil structure for water infiltration and retention. Healthy soil can respond better to drought conditions.

    soil organic
    Before: compacted, poor soil in a newly designated garden area.
  2. Organic growing protects water supplies. By avoiding chemical pesticides and fertilizers, gardeners also protect the water supply. Pesticide chemicals can remain in the soil for years; some are more toxic than others and break down in the soil more slowly. The chemicals from these products can run off into bodies of water, such as rivers. And eventually, they can seep into groundwater. That might seem a distant concern to some urban gardeners, but those of us using wells live right above available water. The more chemicals that run into water supplies, the less safe drinking water is available.

    organic matter on garden bed
    AFTER: Organic matter added to the vegetable garden raised row.
  3. Use of mulch reduces evaporation. A layer of appropriate mulch above the ground around a plant helps reduce ground-to-air evaporation, making the soil take longer to dry out. The mulch also helps cools plant roots. Using organic mulches such as bark, nut shells, compost and others adds organic matter to the soil slowly over time for an added bonus.

    mulching organic pecan
    Rock mulch helps lavender stay hot and dry, and on the lower left, pecan bark mulch surrounds a plant that needs more water.
  4. Organic methods can minimize erosion. Traditional gardening and farming uses rototilling and deep plowing to turn the soil before each growing season. Plowing deeply and turning the soil over can disrupt soil microorganisms, harm soil health, and place looser soils on top, where they’re subject to erosion from water and wind (think Dust Bowl). No-till methods help control erosion and build soil structure. The soils, in turn, better retain water. This can be a problem if the soil drains poorly, but a definite help in low-water regions. Not tilling involves building up beds with organic matter, much like nature does as plants drop leaves that decompose. If you want to work organic matter in, it’s best to grab a shovel. A broadfork is the best tool for breaking up compacted soil.

    watermelon organic
    Healthy babydoll watermelon plant in organic soil.
  5. Growing organically creates healthier plants. Healthy soil is the foundation needed to grow healthy food. When soil has good nutrients and structure, it supports root growth and uptake of nutrients, improving plant health.  Plants that are not healthy are more vulnerable to insect and disease damage. The plant might not use water as it should when it’s stressed, and the gardener certainly guesses that if a plant looks bad, it needs water. So, keeping plants healthy saves the extra water the plant needs or gardener applies in times of stress. And healthy plants keep on going, so you don’t waste water on establishing a plant that later dies from poor conditions.

Plant Select’s Top High Plains and Intermountain Plants

Each year various societies present plant awards, but those of us who garden in the West and Southwest await the group of Plant Select top performers. Plant Select, which is a nonprofit joint effort of Colorado State University in Ft. Collins, the Denver Botanic Gardens and professional horticulturalists, lists five top performers at various elevations.

blonde ambition grama
Blonde Ambition ornamental grama grass tops the 2016 Plant Select list. Photo courtesy of Plant Select.

First, a word about why the work of Plant Select and other regional groups is so important. As I said, there are plenty of awards and lots of information in the gardening world. But, for the most part, plants emphasized by magazines and bloggers are great for East Coast and Southeastern region gardeners. It’s different in the high plains and intermountain areas of the country, where altitude, wind, and heat and cold extremes (in a single day and by season) affect plant health. And let’s not forget the water issue.

Plant Select evaluates plant performance in 53 locations throughout five Western states. Here are some of the 2016 Top Performers. See the entire list at Plant Select.

Grand Winner: Blonde Ambition Grama Grass

Blonde Ambition grama (Bouteloua gracilis ‘Blonde Ambition’ PP22,048) was introduced by New Mexico’s David Salman of High Country Gardens (American Meadows). Blue grama is a perfect low-water native grass grazed on by cattle on our Southwest ranches. Salman introduced the blonde ornamental variety in 2011, and this is the second year it has been Plant Select’s grand winner. Beginning in July, chartreuse blooms (seedheads) appear on upright stems, turning to the blonde color as they age. Watching those seedheads wave in winter winds provides xeric gardeners some year-round interest in their landscapes. Although Blonde Ambition can spread by seed, the seedlings are easily pulled up. The grass is hardy in zones 4 through 9 and deer resistant.

Blonde ambition seedheads
Blonde Ambition looks great in groups or as a single plant in the xeric garden. Photo courtesy of Plant Select.

Top Performer at 3,000 to 5,500 Feet Elevation

Blonde Ambition also tops the list of lower elevation garden performers in the region. Number 2 on the list is a tree I’ve never grown, but want to learn more about since it also topped the list for gardens at my altitude (6,300 feet). The Hot Wings Tatarian maple (Acer tataricum ‘Gar ann’PP15,023) has bright red samaras, or fruit made of paper tissue, that bloom all summer. It’s also known for its reddish-purple fall color. The Tartarian maple is a relatively small tree, maturing to nearly 18 feet high and wide, and gets by with full sun and moderate to dry water needs. The only drawback for me is that it is not deer resistant, but I could see this gorgeous tree in any suburban garden from 3,000 to 7,000 feet in elevation and in zones 4 through 10. We still might try it, but we’ll have to fence the tree until it reaches a mature height and keep lower limbs pruned.

top performer hot wings tartarian maple
The Hot Wings Tartarian maple has a gorgeous canopy, but I also love the trunk. Photo courtesy of Plant Select.

Top Performer at 5,501 to 7,000 Feet elevation

Although the Hot Wings maple topped the list of performers at this elevation, I would like to give a nod to No. 2 on the list – Turkish veronica (Veronica liwanensis). Veronica is an excellent low-water groundcover. Veronica is evergreen, so it covers portions of our rock garden all year long. In summer, the groundcover blooms. Turkish veronica has cobalt blue flowers above waxy leaves. It only reaches about 2 inches in height, but can spread to 18 inches wide. Although veronica is a xeric plant, its leaves look better with a little extra water in the heat of summer. Turkish veronica is hardy in zones 3 through 10 and deer resistant. The top 5 Plant Select performers at this elevation also include Blonde Ambition, Apache plume and a catmint called Little Trudy (Nepeta ‘Psfike’ PP18,904).

turkish veronica plant select
Gardeners can prune Turkish veronica around rocks and paths. Photo courtesy of Plant Select.

Top Performer in Gardens Higher than 7,000 Feet

Fernbush (Chamaebatiaria millefolium) topped the list for higher elevations. The Western native shrub is xeric once established and grows more upright with less water. It can look more formal with rounded pruning in early winter. Deadheading spent flowers also makes the plant look neater, and should be pleasant considering that the foliage has a honey-like scent. The sweet scent also deters deer. Fernbush can grow to nearly 5 feet high and wide; less water keeps it more compact. The plant thrives in full or partial sun in zones 4B through 8.

fernbush plant select
This fernbush provides year-round interest in a high-altitude garden. Photo courtesy of Plant Select.

These are only a few of the top performers in the Plant Select list. Check out their site for more on current and past top performers, new plant introductions for the region and where to buy plants for High Plains and Intermountain gardens.

A Microclimate Experiment

Microclimates can be a farmer’s or gardener’s best friend. A few years ago, I wrote about how use of microclimates, or pockets of a garden that have varying temperatures and exposures to weather elements, can expand your choice of xeric plants.

cactus greenhouse atlanta
This greenhouse in an Atlanta-area garden provides extra heat and sun for the homeowner’s succulent collection and keeps rain off the plants!

The easiest example of a microclimate is a greenhouse. Windows let sun in and walls, a roof and other strategies help maintain the warmth. Add a heating source (and enough space) and you can grow nearly any plant any time of year.

lava rocks microclimate
The Desert Garden at the Huntington in San Marino, California, is a perfect microclimate for cacti. Not so perfect for humans on the day we visited. The lava rocks intensified the 100-plus temperatures.

Subtle microclimates exist all around your yard and gardens. Structures and hardscaping absorb heat during warm hours and release it gradually, helping to protect plants from cold; they also can protect plants from wind. Partial shade shields plants from heat, and slopes or other topography alter how the overall climate affects a given plant.

pond water lilies
Not far from the Huntington, a homeowner’s pond was filled with blooming water lilies in basically the same climate.

The Zinnia Experiment

I would like to say that we planted zinnia seeds in three different places simply to later show how microclimates affected their growth and hardiness. But I’d be pushing the truth. I did plant them in several different spots to see how well they grow here and how quickly they bloom, so I can use them as an easy annual filler to add color and even more pollinators to our gardens.

So, we put seeds in open space in our vegetable farm rows, mostly for the pollinators. We also planted some on a fairly exposed raised bed in our xeric garden. Finally, we planted seeds in the lower part of the xeric garden, close to the rock wall. All of the flowers did fairly well, although the ones in the farm area had better soil and more consistent drip watering. They were the tallest and healthiest. The ones in the raised bed took longer to come up, likely because of poorer soil and an inconvenient hand-watering location. The flowers planted in the lower bed did almost as well as the ones in the farm area.

zinnia cold damage
The healthiest zinnias froze the most, likely because of the farm area location and the fact we had pulled up several rows of faded vegetable plants, so these zinnias were open to a pocket of frost.

Then the frost came and the healthiest plants burned the worst. They more or less bit it overnight.

The zinnias in the raised bed were nearly as bad, but at least the flowers kept their color (I planned to take photos of them, but hard-working hubby cleaned up the bed before I had a chance.)

zinnias minor frost damage
These zinnias suffered some frost damage, but the flowers were still vibrant, thanks to their protected location near the rock wall.

The zinnias in the lower bed fared the best. I doubt they will grow or flower more, but they don’t look like they belong in a horror movie.

How to Use Microclimates

The experiment helped me get a sense of microclimates on our land. We’ve always assumed that our farming area is cooler because it is in a sort of mini-valley jut above the river. The dead zinnias demonstrated we were right, especially since those plants were the most robust before the freeze hit. The flowers in the raised bed are more open to cool air; there were no other plants nearby or much hardscape to absorb heat either.

The hardiness of the zinnias in a more protected and “solarized” spot near the rocks was telling. It’s always important to think about sun and shade exposure, but sometimes we fail to consider how placing a few large rocks behind a cold-sensitive plant can help it survive winter. In vegetable gardening, for example, using fabric to cover plants creates a micro-greenhouse effect. And when growing a plant that needs a little less sun or heat, shade cloth or plant placement can lengthen growing seasons.

shade for vegetable plants
Peppers love heat, but these pepper plants in Tucson had shade over them for protection.

Microclimates, like the general climate, can vary. For example, a tree that drops its leaves provides no shade until it fills in late spring. As trees mature, they can begin shading a plant that once received full sun; it might be time to transplant a shaded shrub. Windbreaks help slow the flow of cold air streaming up a slope.

rio Ruidoso bench
Every gardener needs a microclimate too! we placed this bench in a shaded area near the river as a spot to cool off on warm days working outside.

Containers offer excellent microclimates, not only because they warm up quickly, but because you can move them to solve sun and wind exposure issues, and all the way inside before the first frost.

adenium in container
This Desert Rose (Adenium) in Tucson is about 10 times the size of ours. But its location in a container means that botanical garden staff can move it if necessary for changing seasons and microclimates.

Xeric Plants: Too Much Rain?

You know, I hate to sound ungrateful. We always need rain in New Mexico, if not to water all of the grass, trees and native plants, then to replace our valuable water tables. But in a climate of extremes, especially this summer, we’ve had several weeks of too much water and cool temperatures.

xeric garden after rain
I’m not bemoaning natural moisture. August rains brought greener native grasses and lot of blooming annuals. But it’s good to know what happens when too much rain hits a xeric garden.

Typically, New Mexico and many Southwestern states receive monsoon rain in the summer, and it accounts for at least half of the rain we receive in New Mexico and Arizona. Monsoons can start around mid-June and end late in September. Ours typically begin around the 4th of July. Monsoons consist of short but strong bursts of rain, usually in the afternoon. They’re fueled by the sun’s warming of Southwest land and nearby oceans at different rates. Water evaporation creates humidity over land, forming the clouds that then depend on temperature, atmospheric pressure, winds and mountain slopes to turn into storms.

ravens in dead tree
The clouds seem to bring birds out for active eating before they take cover from summer storms. These ravens love perching in a dead tree.

Typical is key here, however. This year, we had few to no monsoon storms. Instead, we had unseasonably hot and dry, followed by weeks of unseasonably cool and wet. The first rains did wonders at greening up our native grasses and plants. But then in August, the rain and clouds just kept coming. We just had a break, but now Hurricane Newton has struck Mexico and its remnant moisture is headed for southern Arizona and New Mexico.

Rio Ruidoso
Rain replenishes the river and ground water, but excessive moisture can topple old trees.

If arid areas need rain, why is so much rain bad? Flash flooding is a big problem in desert and mountain areas. But how does heavy rain affect xeric lawns and gardens?

First, plant roots need more than water to survive and thrive; they also need air. When you place a new plant in the ground, for example, you should press the soil around it lightly and avoid compacting it to the point that air can’t reach the roots. When excessive rain falls, the water replaces air in spaces around soil particles. As the water drains through the soil, air can again enter the spaces. But if the water keeps flowing from the surface, or especially pools, the spaces fail to open. Eventually, roots can be damaged and fail to even take up the water that surrounds them.

amended soil for vegetables and herbs
Adding organic matter eventually helps compacted soils drain better.

The second danger of too much water is disease. Any fungal organisms in the soil can more easily attack wet plant roots and cause root rot. Xeric plants are not used to so much water on their leaves and roots. Even leaves are affected by too much water falling and sitting on them, especially without sun and heat to dry them again. Plants are more susceptible to leaf diseases such as leaf spot or blight and have less chlorophyll, which affects appearance and photosynthesis. Eventually, poor leaf health can lead to the breakdown of most of the processes that keep a plant healthy and send energy to fruit and flowers.

mushrooms on tree stump
This old apple tree stump started a mini-mushroom farm after extended rain and clouds. What other fungi lurk in our soil now?

Many xeric plants also like sun and a little heat. Native plants have adapted to the Southwest monsoon patterns that usually rule their growing season: A gradual, sunny warm-up in the morning, followed by scattered building clouds. They get a nice drink in the heat of the afternoon, and then the sun comes back out and the air and ground warm up again. This pattern helps dry the plant and soil, and gives the plant plenty of heat and sun. Although nights can be cool in many areas of the high desert and intermountain regions, mornings warm up again after sunrise. Extended periods of cloudy, cool weather lead to too little sun for plants, along with too little heat than they need to thrive and flower.

cracked cherry tomatoes
Tomatoes need some heat and sun, along with consistent watering. These cherry tomatoes cracked before we could harvest them. It’s likely a combination of remaining on the vine too long and a surge of water from heavy storms.

Even edibles can have problems from too much water. They’re susceptible to root rot, depending on lots of other factors such as soil quality. Leafy vegetables and herbs flower early. Tomato fruit tastes better with moderate water. Too much water, especially inconsistent amounts, can cause fruit to crack.

Keeping Xeric Plants Alive During High Rain Periods

Make sure all plants, and especially those susceptible to root rot, are in soil that drains well. Raised beds, mounds or berms, and suitable containers can help drain soil around plants much better than compacted soil. If you’re not sure how well your soil drains, you can typically tell when it pools or soaks in hours after heavy rains. Or you can try the test in this handout from TreePeople that times water drainage.

okra plants
My husband is much better at spacing plants than I am. These okra didn’t get enough heat to produce much, but spacing helped the fruit get more sun and air.

Provide air circulation. We all have a tendency to place new plants and seedlings too close together. You might as well get as many cucumbers as possible in the limited space you have, right? But lack of air circulation in crowded plants hides bugs, causes the leaves to maintain moisture, and even can shade ground around roots. Wet conditions harbor new problems that native plants in particular can’t take.

California poppy
Flower from a poppy (Mexican gold or California Eschscholzia californica) thrives in drought, but can bloom more in heavy rain. As for the “garden art” it borders, that’s something personal between Tim and a steer.

Another problem with extended periods of rain is weed control. Although mostly native, the darn weeds seem to love excess moisture. And before you know it, they crowd and wrap around important garden plants or shading grasses. It’s hard to control them if the ground is too wet to mow or you can’t even get outside.

Build raised beds or transplant susceptible plants to higher ground. We’ve had some drainage problems near our patio and are working on a dry river bed to divert water away from the house foundation and down into a grassy area, where it can soak grass and eventually add to groundwater. One step we took was to divide a blue mist spirea (Caryopteris clandonensis) and move the portion near the patio onto a small burm. The xeric plant is so much happier now.

blue mist spirea berm
The dry bed is a work in progress, but just moving this blue mist spirea to higher ground saved the plant.

Whatever you do, don’t water! Turn off drip or sprinkler systems during and after periods of rain; it’s just the responsible thing to do. And don’t assume that yellowing leaves indicate the need to water. With too much water, the leaves look sort of floppy, but too little water usually causes dry, brittle foliage.

Finally, don’t stress. You can’t control weather, so simply keeping your plants as healthy as possible within time and weather constraints is all a gardener can do!

Diagnose and Prevent Drought Stress in Plants

A droopy, wilting plant. It’s a gardener’s instinct to automatically assume: It needs water. And sometimes, that’s a good instinct. But low-water plants just as easily can be killed by kindness as by neglect.

gladiola
Gladiolas like an inch of water a week, but not too much water.

For example, several problems with tomato fruits are caused by too much water, or especially irregular watering. Plants, like people, need some regular hydration. You wouldn’t avoid drinking water for five days and then gulp down a liter, right? One reason drip systems are effective is the consistency (assuming you set a timer) of the amount of water they deliver, along with the slow rate of flow and the fact that they water the soil/roots and not a plant’s leaves. The delivery and slow flow help retain more moisture and nutrients around the roots.

A drip system with adjustable emitters is a great way to water our okra. And it looks like to attract ants...
A drip system with adjustable emitters is a great way to water our okra.

What’s the prognosis?

There are reasons other than drought stress that cause plants to wilt, including problems with the roots. That’s why plants you’ve just transplanted from seed or a nursery container tend to wilt for a few days or weeks. The roots suffer some damage when taken from a pot and replanted. Understand that this is part of the natural course of the plant’s life and help it through without stressing too much (meaning you, not the plant). Even though a plant is waterwise, it still needs extra water until the roots heal and begin to grow, more efficiently pulling water into the plant. If the ground is dry at root level, the roots can’t do their work. Plants that are overwatered sometimes wilt, too, further complicating the “diagnosis.”

tomato branch broke water
After our first heavy rain, I accidentally brushed against a branch of this currant tomato.It peeled off; the brown leaves are likely from that damage, not from lack of water!

Speaking of, most gardeners jump to the worst possible scenario when determining a plant problem. Although disease is a possibility, look not only for symptoms of a particular wilt or fungal disease, but also for possible causes. Do you have evidence of bugs that might have damaged leaves or carried a disease to your plant? Is the plant getting enough air circulation? Is water running off and away from the plant? Has it just been super hot for several days?

incipient wilt
Incipient wilt on a squash. Still not the best scenario and a signal to check our soil, but it’s temporary.

The best way to distinguish drought stress from other causes of wilt is by looking at and feeling the soil. Damp soil means the plant has water available; adding water at this point likely won’t help. You should feel an inch or two below the surface. One way is to stick your finger in the dirt to about the first knuckle joint.

Prevent plant stress

When a plant needs water, it’s more susceptible to damage from bugs and diseases. Pests attack the weak. You can prevent plant stress from underwatering by:

  • Checking the soil as mentioned above; see if there is water for the plant.
  • Looking for signs of underwatering. These usually include leaves turning yellow and brown, and even falling off. Typically, drought stress begins with lower leaves.
  • Thinking about the plant’s environment and how it might have changed. Is it windy and hot or muggy and cool in the evenings? Did you last water a plant in the afternoon out of necessity instead of your usual morning routine?
hot day on plant
Not much you can do about these weather conditions within a week or so of placing new plants in your landscape. Water consistently in the morning and shade plants if practical.
  • Using a meter or records when in doubt. We have an inexpensive moisture meter for our farm area. If nothing else, it helps confirm or deny my suspicions about the need to water and gives me a basis for comparing soils or drip rates around certain plants. Keeping records of watering, fertilizing and other activities can help manage and diagnose plant problems.
water meter to check moisture
Geraniums like to dry a little between watering. An inexpensive meter might not be the most accurate tool, but can help a home gardener check soil moisture.
  • It’s always better to water before a plant wilts, and not to wait until wilting occurs. Although plant roots need to seek water, they also have to find it! When no water is available in the soil around them, plants can begin reacting with wilt, slowed growth or flower and fruit production, and other signs.
xeric bush spirea
Blue mist spirea is a low-water plant. If the leaves have spots, it’s more likely getting too much water than not enough.
  • Finally, remember there is no hard and fast rule on watering. Much of the advice I see comes from areas that are more humid, cooler, less windy, and at lower altitude than our conditions here in New Mexico. Having said that, you can create conditions that help plants retain moisture, mostly by ensuring healthy soil and mulching. Containers need a little more frequent watering because they dry out faster than the ground. Water container and landscape plants slowly so the moisture drips instead of flooding down. You probably only need to add water to a container when the top few inches of soil are dry.

 

 

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.

Six Money-saving Tips for Home Gardeners

Getting started gardening requires some upfront investment, but you can have a nice garden or lawn and stay on budget with a few simple tips. Here are some ideas we use to save money:

Gardening might cost a little to get started, but not if you reuse and repurpose. Perennial plants last, and some re-seed year after year.
Gardening might cost a little to get started, but not if you reuse and repurpose. Perennial plants last, and some re-seed year after year.

Repurpose containers. Sure, I partly mean to re-use the same pots year after year. But I also mean to look for found objects and turn them into containers. Buckets and pails make great containers, for example. Just drill one or more holes in the bottom for drainage. Old metal baskets also look really cool for hanging plants. But they will need lining with moss or cocoa fibers to help control water. Choose your material based on how much water you want to remain in the basket.

This old milk can makes a great container for an aloe plant.
This old milk can makes a great container for an aloe plant.

When re-using pots from previous years, be sure to empty dirt out in the fall and wash the container then and/or before planting again in the spring.

I grew some lettuce in this container in spring, and switched to flowers when it got too hot. The pencil cactus in the second container comes from my daughter's yard.
I grew some lettuce in this container in spring, and switched to flowers when it got too hot. The pencil cactus in the second container comes from my daughter’s yard.

Grow food. Save money and even water by incorporating food into your landscape. Fruit trees double as shade trees as they mature, which can lower energy costs. Growing just one or two vegetables that you purchase regularly at the grocery store can save money on your food bill with the minimal investment of a plant and soil.

Tim found this old screen door and for now, I'm using it as a decorative trellis for a few small cucumbers.
Tim found this old screen door and for now, I’m using it as a decorative trellis for a few small cucumbers.

Use household or found items. Whether for garden art and interest, staking a plant or shading a new transplant, don’t be afraid to get creative with items you already have. A garden should be a retreat for you and your family and reflect your taste and comfort. I’m not suggesting you place eyesores in your front lawn, but household and kitchen items can be really useful in the garden. We re-use buckets and pieces of fencing to warm plants or keep deer off. Lots of kitchen items are touted for garden uses. Eggshells might not stop snails altogether, but the crunchy shells might cause them to detour at least. Coffee grounds have some use, but see this handout for a scientific look at their effectiveness.  At the very least, add them to your compost.

These new plants wilted from the heat yesterday, so we got out the lawn chairs. I know it looks funny, but it's in the back yard and temporary. The chairs give filtered shade, but allow air to circulate. And I put a few yard staples in them to keep the wind from blowing them away (or onto the plants).
These new plants wilted from the heat yesterday, so we got out the lawn chairs. I know it looks funny, but it’s in the back yard and temporary. The chairs give filtered shade, but allow air to circulate. And I put a few yard staples in them to keep the wind from blowing them away (or onto the plants).

Compost. Worms really love coffee grounds, and if you decide to start creating vermicompost (worm castings), hold on to the coffee grounds and newspapers! Making your own garden compost (without housing worms) is another easy and inexpensive garden improvement. Check online for plenty of plans and ideas for homemade compost bins or buckets. Just be sure to also research what can and can’t go into the pile (I keep a cheat sheet near the sink) and how to keep the compost fresh, damp and turned.

deer fence vegetable garden
This compost bin is right by the garden, and we have a wooden one closer to the kitchen.

Save seeds or divide plants. Saving seeds from spent flowers is a great money saver for next year. You can keep seeds in simple zipped plastic bags, as long as you store them in a cool, dark spot. If saving seeds for vegetables, you’ll have better luck if you only save seeds from heirloom varieties, or purchase a new packet every few years. Seeds do not cost much at all. We divide or move plants to fill empty spots in our garden, and you can likely find a friend, neighbor or coworker willing to trade your iris bulbs for his daylilies.

Choose perennials. Perennial plants come back year after year; their life span depends on the plant and conditions (such as a really hard freeze). Perennials cost a little more from a nursery, but since they return, you save money the following year. That’s assuming that you water the plant a little more heavily than its instructions say until it seems well established in your garden and place it in the right conditions (zone, sun, etc.). Just ask for a little help from local nursery staff or experienced gardeners; they love telling you about their favorite plants.

You can fill a few bare spots with annuals, especially from seed, and including annual herbs for your kitchen or flowers you can cut and use for arrangements. All it takes is a little planning and ingenuity to grow what you love and on a budget.

How To Grow Your Own Cooking Herbs

Herbs are delicious additions to so many dishes, and several popular herbs are easy to grow at home. You can save money and time flavoring foods by growing one or two of your favorite herbs in containers or flower beds near your home. Try the herbs listed below for the joy of cutting just enough fresh leaves for your recipe and the pride in growing the plants yourself.

fresh cut herbs from home garden
From left to right: sage, thyme, oregano and basil.

First, here’s a list of herbs that grow well in dry climates; in most parts of New Mexico and the desert Southwest, these herbs can be perennial plants in your landscape, coming back from year to year:

  • Rosemary. This aromatic herb is my favorite for growing and cooking. The drier, the better, once it’s established. And you can grow rosemary for its woody habit and tiny purple flowers.
rosemary in waterwise garden
This rosemary is an ornamental, but I have harvested from it. Note the santolina that fills most of the frame. It’s considered an herb as well. I love the yellow flowers it produces in summer.
  • Sage. We grow sage more as an ornamental, but I dried leaves last year for use in poultry dishes. Bees love sage flowers.
  • Lavender. Sure, you can cook with lavender (check out our Pinterest board for some recipes). And it’s the perfect plant – herbal or ornamental – for a xeric garden.
lavender plants in New Mexico
In addition to more than a dozen lavender plants for cutting and their gorgeous shape, we have one in a container just for culinary use.
  • Oregano. Culinary oregano is easy to grow and is hardy down to zone 5. Capture its best flavor by harvesting just before the plant blooms.

Annual herbs you can plant each year or rotate:

  • Basil. We grow from seed, but you can always find great basil plants in stores.
  • Dill. The tall aromatic plant is great for rock gardens. You can harvest seeds or leaves.
Dill is a versatile herb.
Dill is a versatile herb.
  • Parsley. The plant is an annual in most regions, unable to take a hard freeze. It’s the most popular herb used around the world.
  • Cilantro. This is a must-have herb for Southwestern dishes and it takes a big bunch for most recipes. Cilantro loves sun and often re-seeds. The leaves are delicious and the seeds (coriander) are popular in many recipes.
Young cilantro plant grown from seed.
Young cilantro plant grown from seed.
  • Fennel. Tim loves the smell of fresh fennel, which resembles that of licorice. Although it prefers sun, new plants come up at the base of larger bushes in our garden. Fennel can become a weed in the right (wrong?) conditions.

Tips for herb growing and harvesting

Most annual herbs are easy to direct sow, or grow from seed right in your garden or container. Many perennial herbs, especially rosemary and lavender, grow best from cuttings or transplants. Be sure to choose a large enough container for your herb and choose a location that gives the plant enough sun or shade, depending on its needs. If this information isn’t on the tag or seed packet, check with a local or regional source such as master gardeners or your state and local cooperative extension service.

Protect tender herbs from pests. I keep basil covered all year with row cover cloth because every bug seems to love it as much as I do. And I just found out that some critter visiting our yard loves dill, as did the swallowtail caterpillars I found on it the other day (and moved to the fennel; sorry, Tim). If you can grow inside a fence, great, but we’ve incorporated herbs into our rock garden. Either choose those that your local pests don’t prefer (for us, that’s rosemary, lavender and thyme) or find a way to cover them.

I saved new dill plants from caterpillars only to find them nearly decimated this morning. I'm not sure of the culprit yet.
I saved new dill plants from swallowtail caterpillars only to find the plants nearly decimated this morning. I’m not sure of the culprit yet.

Harvest most herbs all season. Once a plant is sturdy and bushy, you can begin harvesting. Once an herb flowers, it can bolt in growth and lose or change flavor. But I’ve harvested rosemary from a plant already flowering, and then trimmed it back lightly in spring. I’ve been letting older thyme plants flower and try to keep younger ones managed for harvesting. In general, harvesting invigorates herb plants. So it’s best to use the leaves! Here are tips on cutting basil, along with a pesto recipe.

These lavender buds are just opening, and are useful for more than cooking.
These lavender buds are just opening, and are useful for more than cooking. That’s a white larkspur that happened to self-sow in the center.

Drying herbs is easy. I hung most in bunches from rafters in our shed, then stripped the dried flowers or leaves. You can also find plenty of products and ideas to help if you like. Here are tips on drying herbs from the National Center for Home Food Preservation.

Sage leaves are easy to dry with cut stems hung upside down.
Sage leaves are easy to dry with cut stems hung upside down.

Winter over or move indoors. If you’re not inclined to dry herbs at the end of the season, try wintering the plants over. Perennial herbs for your zone might need protection, but should make it in all but the coldest, snowiest winters. An advantage of container growing is that you can move the container indoors or to a warmer winter spot. Even if your indoor herb fails to last the entire winter, you extended the time during which you could clip just enough herbs for a favorite family meal, right inside your own home!