Water Under, Not Over, a Plant

For water conservation and plant health, the smartest xeric strategy is to water the roots of the plant and avoid watering the plant’s leaves.

Let’s look at the water savings first: Water evaporates when exposed to air, and occurs at the water surface area. The smaller a drop of water, the higher the percentage of the drop’s surface area. Add the effect of wind on tiny drops of water from sprinklers and you might as well just pour that water down the drain. And if you irrigate a plant from above or with sprinklers and spray emitters, much of the water lands on the leaves, where it can evaporate. In fact, water constantly evaporates from a plant’s leaves as it is, in a process called transpiration. It’s a plant’s natural way of cooling off on hot summer days.

herb garden drip irrigation
Cascading or spraying water is for fountains and lawns, not for plants. Note at least three inconspicuous, but efficient, drip emitters in this herb garden.

Feed a plant’s roots

It’s much better for a plant to take new water in through the plant’s roots, where the water picks up soil nutrients and works its way up the trunk and stems back to the leaves to do its cooling and feeding work. There’s another reason not to spray water on plant leaves, especially late in the day or during cloudy, humid weather: wet leaves can harm many plants.

Fungal diseases such as powdery mildew on roses or apple scab on apple trees and crabapples is partly a result of water on the leaves. Sometimes, there is nothing a gardener can do. We have an old apple tree with some scab that likely came from spores in old leaves left on the ground and a week or more of cool, cloudy and humid weather in late spring.

apple scab on leaves
We don’t water this old tree near the river, but an unusually cool and damp late spring caused this brown spotting, which I believe is apple scab. It was worse on lower leaves on the northeast side of the tree, but seems to have stopped progressing. And the apples don’t look too bad!

Change how you irrigate

Often, simply changing irrigation practices can improve a plant’s health. When we first moved to a home in Albuquerque many years ago, the previous owner had installed sprayheads in all of the flowerbeds. We eventually had to replace all of them with bubblers and rework the plantings. Bubblers or drip irrigation might have required a little more planning, better leveling of the soil and more parts or emitters. But in the end, the homeowner would have saved money on his water bill and I bet on plants! Farmers know this is the way to go, and many are learning new ways to improve irrigation techniques to reduce water use.

subsurface drip irrigation
A micro subsurface drip irrigation system was used in this demonstration project in Texas. Click on the image, which is courtesy of the U.S. Department of Agriculture, to learn more about the project.

We recently visited a nursery in search of tomato cages and noted that the tomato plants they still had in stock looked awful, even though they had a few large fruits on the plants. I thought at first it was too shaded in the greenhouse, but then Tim noticed the cause: an overhead spray watering system. The leaves were spotted and nearly goldish-brown in color. I don’t know how they are healthy enough to continue feeding the plants. Granted, these plants have been in the greenhouse way past the typical time, and there are many more than you would have to deal with in your garden. Still, it seems to me they would sell more tomato plants if they watered differently.

rose water pail
Roses are especially vulnerable to powdery mildew and need deep watering at the roots. The only time I spray roses is to rid them of aphids. I use a fairly strong water spray early on a sunny day.

And in case I haven’t convinced you, here’s yet another reason to water with drip emitters or by hand near the roots of a plant instead of broadcast or spray irrigation: weeds. When you spray water, you water everything around, including weed seeds. Watering only around your vegetables’ or ornamentals’ roots confines weed growth, making it easier to pick small weeds out by hand.

hose watering tomato
It takes more time to water my vegetable garden by hand, but the hose from our rain barrel waters the plants deeply and just at the roots while I weed.

As I said before, you can’t control rain, which obviously comes from overhead. But keeping plants exposed to proper sun, trimmed and cleared to give them sun and airflow and cleaning out debris from around the bottom of trees and plants can help reduce risk of fungal diseases. Choose mulches carefully, depending on local recommendations for a given plant.

Easy Rain Barrel Project: Collecting Rain from Shed Roof

For two years, I’ve watched rain pour off the roof of an old shed in our orchard and hated to see it go to waste. And our vegetable garden is only about 20 yards from the shed, so it just made sense to capture some of the water. This weekend, as storms approached, we got around to adding rain gutters to the back of the shed to catch some of the precious rain in a barrel.

old shed in New Mexico
I love this old shed. We use it for storage, but it had no rain gutters for all of the runoff.

First of all, this was a relatively easy and inexpensive project. We already had the barrel, which cost about $80, in the shed. One of the drawbacks of the barrel type is that it tends to leak along its outside seams. Tim caulked and duct taped it for safe measure. The gutter, outlet and brackets came to about another $60. We had old hoses to reuse.

shed rain barrel project
The metal gutter Tim bought matches the barrel and the shed, so it doesn’t affect the character of the shed much. We attached it to the joist beams along the back, just under the roof. See how close all that wasted water is to the garden?

Tim picked up two pieces of metal gutter, which covered most of the 24-foot roof, some slip joints to connect pieces, two end pieces and the outlet. The most time-consuming part of the project was bending the metal gutter pieces to fit together. Then we caulked them.

We used metal brackets to connect the gutter to joists on the shed. Some of the joists were beginning to rot at the top, so we connected the brackets to the strongest ones and then reinforced the gutter with screws in other spots.

attaching metal gutter to shed
Metal brackets secure the gutter on both sides every 18 inches or so.

We sat the barrel on a found, fairly flat rock for some ground clearance around the lower faucet control and plugged the other hole with PVC pipe (this barrel also had a busted faucet). I’ll only be needing the hose connection. The garden is downhill from the barrel, which makes the hose flow more easily. And we stacked a few rocks around the sides of the barrel to help with drainage and mud control from overflow.

Because the ground was so high in relation to the back of the shed, we haven’t bothered yet with a downspout; the outlet is only a few feet from the top of the barrel. We figured that if it missed, we could repurpose some old gutter we cut off the house when fitting barrels on it. But we found out that wasn’t necessary! When the rain came, it flowed right into the barrel and filled it up.

rain barrel filled
The barrel installed and filled to the brim after nearly an inch of rain later that day!

I realize this barrel won’t hold enough to water my garden all of the time, but it helps. And if it works well, we might chain another barrel to it next year. I don’t worry too much about using water from the metal roof on my vegetables. First, I water the soil, not the plant’s leaves. Second, there has been plenty of research done on safety of rain barrel water for edibles. We don’t have pollution where I live, and I’m using well water if I don’t use rain water, so it’s not like I’m choosing water from a roof over city tap water. I make sure I rinse all harvested food.

This was a fun, easy and rewarding project. With the rain we received, I haven’t had to use the stored water yet, but I’m sure I will need it by the end of the week!

How To Water Mature Trees

When drought strikes, it’s tempting to cut back on watering of established trees or stop watering altogether. And maybe water restrictions in your area force your hand. I hate to see it happen, because trees can offer many benefits – most notably shade for homes to cut down on energy use, and shade for other plants to keep them alive and in need of less water. Of course, you can’t beat the enjoyment of sitting under the shade of your favorite tree. I won’t even get into how depressing it is to see dying trees in front lawns…

Ideally, your lawn has only native trees, and especially xeric varieties. In that case, the trees adapt to conditions more easily. Some survive on rainwater alone, but most need a deep watering about once a month during the heat of summer.

desert willow tree xeric
The desert willow (Chilopsis linearis) is a perfect xeric tree for warm to hot desert climates. This one is from a Tucson, Arix., garden.

To water your a mature tree that requires irrigation, avoid a common mistake — watering only near the trunk. Trees do not have tap roots, but instead have a root system that extends out from the tree, more or less mirroring and extending just past, the tree’s branches above. So, when you set out your hose or set up a drip or soaker system, begin near the trunk, and then work your way out to the edges of the tree’s canopy. Scroll down in this handout on caring for trees from Colorado State University for a photo of a soaker hose layout.

To water deeply, you have to water slowly. That means setting your hose or irrigation system to deliver the water at a lower rate for a longer period of time. To reach the roots, the water needs to penetrate the ground to at least 12 inches. If you’ve ever seen roots growing at ground level, they’re probably doing so because the tree is receiving too little or too shallow watering.

Don’t dig a hole around the tree to help get water to go down deeper. The hole allows air in and dries out roots!

If possible, avoid using a sprinkler to water trees. In addition to producing shallower roots, the sprinkler wastes water by dispersing it into the air, where it evaporates. And some trees are subject to leaf diseases from constant watering. The only time I ever spray a tree or bush is if it has aphids, and I give it a fine-water spray in early morning to wash the aphids off.

If you can’t reach a tree with your hose, you can drill a few holes in a 5-gallon bucket and carry it out to your tree. The water will flow more slowly through the hole than if you pour the water on the ground. Move the bucket out and around the tree’s base with each refill.

apple tree along river.
This apple tree is hard to reach with the hose, but we don’t water it because it is along the river bank and the roots take up plenty of water. This year, it had twice as many blooms and may give us some fruit. Trees can help preserve water sheds.

If you want to save tap or well water, reuse! Direct roof water to a tree using the downspout and a dry river bed. Save shower water in 5-gallon buckets (with no holes – you have to get them outside!) but only use the water that flows while the shower warms up, not any soapy flow.

If you have other clear water to dispose, such as kid or dog pools, empty the water onto tree roots instead of a random place in the yard.

Another Reason to Weed Your Garden: Water Savings

If you’re like me, you hate the sight of weeds in your ornamental or vegetable garden, and you have permanently discolored cuticles from April through September.

Weeds are more than unsightly, however. Ask any farmer, who knows that weeds can reduce their crop yields by at least 50 percent by simply robbing crops of water. Although weeds can seemingly grow out of rocks, parched dirt or sand, they still compete with surrounding plants for water. Weeds also host bugs and diseases and can block sun or air circulation to important plants. For example, if a tall weed shades your bell pepper plant, the plant is less able to compete for water and nutrients and less likely to produce as many peppers. Some weeds even introduce chemicals that are toxic to certain plants, animals and people.

Weed growing in middle of sage
This culinary sage has a weed growing up through the middle of it. The weed’s tap root likely steals rain water from the sage.

Are you hating weeds as much as I do yet? There are those who tout their benefits. A few weeds provide nectar for bees or help supply organic matter to soil. And as I’ve mentioned before, there is a fine line between weeds and wildflowers. Our widespread alyssum invasion each spring adds early color and brings hundreds of bees to our land.

Further, several weeds are edible. Examples that come to mind are dandelions and purslane. But I really prefer carrots and cucumbers.

According to Robert Parker, Ph.D., of Washington State University’s Cooperative Extension Center, it’s more important to control weeds during drought than during typical years. And some common weeds consume more water than typical crops. An example is Russian thistle, which Parker said removed nearly 18 gallons of water per plant while competing with a spring wheat crop. The thistle is just one of the weeds we are trying to attack here on our property and a priority throughout Lincoln County, N.M.

thistle weed
This thistle (to the upper left of Buster) is growing in our ditch, along with a horehound and numerous other weeds. I need to grub it before it goes to seed.

Parker says that crops are most affected by weeds during early growth. So home gardeners are best served by prepping their gardens carefully to start out with a clean slate and to handpick weeds until their backs give out. Seriously, it’s always best to keep weeds under control without chemicals if possible. That’s especially true during a drought, because most herbicides require water to work effectively.

In fact, weeds are the ultimate native plant! They adapt to drought by developing ways to retain moisture in their tap roots or waxy layers on leaves. When drought affects grass growth on rangelands, more weeds move in and establish squatters’ rights. That’s what seems to have happened to us. We now have a proliferation of several weeds, and especially horehound (Marrubium vulgare).  Horehound grows best in dry soil, and I’ve seen it growing in the worst places possible.

horehound
Horehound, which is considered a good plant or an awful weed.

From what I can tell, horehound spreads by seed, but also has runner-type roots and maybe spreads just by magic. It’s in the Lamiaceae, or mint, family. Need I say more about its invasive qualities? And although a noxious weed in some areas, horehound also is considered one of those “good” weeds, having both medicinal properties and use as an edible for tea or candy. But I point to the “vulgare” portion of its name. If it continues to take over our grass, I might give in and learn how to make the vulgar weed into candy, which apparently tastes like licorice.

horehound spreading
Horehound mowed down to prevent seeding, like that will help. It is taking over this grassy area.

Most likely, we are going to require herbicide at some point. By the way, the horehound noxious weed spread began when it was introduced to ornamental gardens. I’m all for growing edibles, but why not mint in a container?

Plan a Xeric Turf Lawn

Because the drought in California is so severe and restrictions attempted earlier this year did not have much effect, regulators adopted unprecedented restrictions at the urging of Governor Jerry Brown that include encouraging homeowners to let their lawns die. A survey of the state’s local water departments showed that water use fell less than 4 percent in March of this year compared with March 2013; total water use has gone down only about 9 percent since summer 2014. The new regulations require cities to cut use by up to 36 percent.

What remains to be seen is how cities will enforce the laws, or help homeowners do a better job of conserving water.

all-gravel lawn
This is the choice of most homeowners who xeriscape, and now the only choice in drought-stricken California. Note the bermuda grass creeping back through the gravel.

Some of the crisis could have been avoided with xeriscaping years ago. Californians and any of us in arid Southwestern climates do not have to  give up on turf lawns completely, at least if we act before a crisis of California proportion hits. You can responsibly incorporate some turf into your xeric landscape rather than going all gravel. Let me first explain the benefits of keeping a limited amount of turf.

  • As I’ve mentioned before, xeriscaping includes zones, and the zone closest to your home is called the mini-oasis. This is where you should plant turf and your highest water users, keeping “highest water users” relative in scope and quantity. One reason is that you can water some of the plants in this area with rainfall runoff from the roofline and downspouts. And when in a drought, you should catch as much rain as possible.
  • The other reason to have some planting and green around your home is to help keep your house cool in summer. This might not be as important if you live in the mountains (although if you do, I bet you are like us, and rely on cross-breezes and cool evenings instead of air conditioning!). If you switch to all gravel instead of some grass or native plants, your house will become hotter, and eventually you’ll use more energy to cool your home. If you have evaporative cooling, guess what? You’ll use more water, too.
  • Any trees planted near the house that help shade it in summer will likely die if you cover their roots with plastic and rocks.

I’m not saying you should sod a huge lawn or use any grass you like, however. Many people in Albuquerque, where average rainfall is 12 inches a year, have planted lawns made up of a Kentucky Bluegrass mix. Those lawns need about 40 inches of rain a year, and I don’t have to tell you that Kentucky is hardly a desert…

So, what’s the ideal situation? Plant a small area of native, low-water grass near your home (especially on the south or west sides) or around the base of the tree that shades your house. Native grasses have adapted to live in their environment, and should thrive in your climate with little to no supplemental watering. Here are a few examples of sod-forming grasses:

  • Blue grama (Boutleoua gracilis). Blue grama is best known for its seed heads, which form in middle to late summer, assuming you stop mowing for a bit and let them go to seed. The low-water, warm-season grass has fine green blades and loves hot weather. It will winter over in cold climates as well.

    Dried grama grass seed heads
    We mowed around this clump of blue grama for weeks last summer and fall to let it go to seed and hopefully spread. This is how it looks in early spring.
  • Buffalograss (Buchloe dactyloides). Buffalograss is a native prairie grass that establishes quickly from seed or starter plugs. It won’t work as well under a tree or the shade of a house as some natives because it prefers full sun. But the warm-season grass requires little mowing and only two inches of water a month, even in the hot summer.
  • Western wheatgrass (Pascopyrum smitthi). This cool-season grass works in most soil types and uses little water. It has bluish leaves and spreads by rhizomes, so be careful where you plant it. Also, the grass is native to high elevations.
winter wheatgrass
Winter wheatgrass in a New Mexico horse pasture.

You also can mix buffalograss and blue grama for a native lawn that fills in quickly and densely.

blue grama grass in spring
This is some blue grama grass near the clump that went to seed. It’s greening up nicely in early May with only rain water and some fertilizer from deer.

Avoid planting turf on a slope, and keep your small lawn area away from sidewalks or curbs, so that when rain or the occasional sprinkler water hits the grass, the moisture stays there and doesn’t run off.

Finally, with native grasses, you have to learn to go with the flow, so to speak, and not expect to have the greenest, most dandelion-free lawn on the block. The lawn’s health will vary from one year to the next. We have several acres of various native grasses and even more weeds. Obviously, we do not water any of the lawn/pasture. It’s completely up to Mother Nature. We control the weeds in some areas and mow when it all begins to grow in late spring or early summer.

salinas-pueblo-missions-natural-grasslands
Natural grasslands at Salinas Pueblo Missions, a national park near Mountainair, N.M. I am certain this grass receives no irrigation.

 

Harvesting Rainwater for Your Garden

The drought is easing here as April showers finally arrived and turned into a few May thunderstorms. Our rain barrels are overflowing, and it makes me happy, but crazy. (I need to check and see if I say “xxx makes me crazy” on every post. This is a troublesome pattern.) Anyway, I hate to see any of that precious resource go to waste. In reality, I know it’s watering the natural grass, trees and plants, flowing into the river, and adding to our water table. But I want to collect as much of it as I can to avoid use of our well water for most of the year.

Backyard rain barrel
This is a basic, 50-gallon rain barrel used as needed for xeric ornamentals and herbs. I’ll use it soon for some vegetables.

From 30 percent to 50 percent of public or potable water in a given community can go to landscaping. I know we could use more than that between our fruit trees and vegetable gardens. It’s imperative that we all continue to find ways to cut the amount. I tackle that as often as I can on this blog, but for now, I want to focus on rainwater collection and safety of rainwater for edibles.

Rain barrels and cisterns

Our two 50-gallon rain barrels just don’t cut it. And I have big plans to add more, including a huge above-ground or underground cistern. Most homeowners use barrels similar to ours to water ornamental gardens. We’ve found that they’re easy to install, and work pretty well, although Tim has had to replace the faucet on some. You can add a hose to the bottom of the barrel or fill a watering can from the spigot. The barrels cost around $80 to $135, depending on quality, size and appearance.

bottom or rain barrel with faucet
Our basic barrels have a spigot for filling water pails and a hose connection.

Cisterns cost more, and generally are used by commercial operations. But if we ever get our greenhouse (see my comment above about what makes me crazy, as in not having one yet), I think it would be difficult and irresponsible to add year-round gardening without having rainwater collection. A 1,000-gallon tank runs close to $600 or more, and you can expect to pay up to $5,000 for a 10,000-gallon cistern, plus excavation if it’s going underground. Of course, with all cisterns, you have to consider some installation costs, plus shipping or transportation and permits in some cases.

Roof water for vegetable gardens

In the past, I heard that roof water was not safe for watering edibles, and I avoided using rain barrel water from my tar and gravel roof on herbs or vegetables. But we now have a metal roof, and I feel comfortable using the barrels to water ornamentals and edibles. I wanted to back that up with science, however, so I found some great information from Rutgers University’s New Jersey Agricultural Experiment Station.

downspout over rain barrel
A metal roof, gutters and downspout bring water to our two rain barrels. The barrel has a screen to prevent debris or birds from getting inside.

The study tested safety of rain barrel water for irrigation of a vegetable garden. In short, they found that rainwater collected from asphalt shingle roofs met irrigation water standards, with a few exceptions. E. coli sometimes appeared in the samples because of droppings from birds, squirrels or other animals. And rain barrel water is not safe to drink, but is considered safe to use to water the soil (roots) of your vegetables. The authors of the study recommended a few practices to ensure the rain water remains safe:

  • Clean rain barrels with a 3-percent bleach solution before collecting water you’ll use for herbs and vegetables. Since you need to empty the barrel before winter (unless you are in a mild climate), you can clean it before each spring. Or simply add household bleach at a rate of 1/8 teaspoon per gallon of water twice a month during heavy rainfall). It’s diluted enough to prevent any harm to plants after about 24 hours.
  • Pour the rain water directly onto the soil, not on the plant’s leaves, or use it in drip irrigation.
  • Water in the morning and harvest at night. This gives the sun’s rays time to disinfect leaves. Morning watering is a better xeric technique, anyway.
  • It also helps to clean your gutters before spring rains hit, just to cut down on dirt and debris.

Altitude and Wind Affect a Plant’s Water Needs

If you’ve ever gone skiing or hiking in the mountains of the Southwest, you’ve heard the warnings (or ignored them and learned the hard way). Drink lots of water, more water than you normally drink. You also might have noticed that you became breathless a little more quickly. All those warnings aren’t just designed to impress flat-landers or to make up for exertion. There’s science behind high-altitude dehydration of people and plants.

Low Pressure Causes Evaporation

Air pressure is lower at higher altitudes, and that means that moisture evaporates more quickly. It evaporates from lungs and from the soil and roots around plants. Add the fact that most high-desert and mountain climates also are low in humidity, and you’ve got to adapt to a new environment or nearly pass out. The same goes for your landscape, which is another reason to stick with native plants. These guys have toughed it out; they’re not just here for a weekend getaway! If you do choose non-native cultivars, plant them sparingly, and try to use them in protected areas, which leads to my next point.

 

snow on southwestern mountains
My daughter took this photo of snow on the mountains along the Arizona-New Mexico border one December. A holiday snow does not mean a humid climate.

Why Not Add Some Wind to the Mix?

Luckily, winds are worse in New Mexico on the plains than in the mountains. But how about in the high desert? Because of the wide temperature variations – warmer days and cool evenings, desert air can be a little unstable. Anyone driving through rural Arizona and New Mexico is likely to see a few wind farms, a smart renewable energy choice for our state.

Windy air contributes to evaporation. As wind speed increases, plants react by upping their rate of transpiration, which is the plant’s loss of water as it’s absorbed through the roots, up to the leaves, and out the leaves as it evaporates. More than 90 percent of the water a plant absorbs is lost by transpiration. It’s inevitable with photosynthesis.

wind spinner in New Mexico garden
This wind spinner is calm today, but we had to permanently shorten the stake to stabilize it because it almost took off in flight or bent in half a few times this spring.

It’s easy to imagine that wind makes plants drier, as anyone who lives in a windy, arid climate knows when they constantly apply lotion to their skin. Science also explains the effect of wind on evaporation. First, it’s helpful to recognize that plant evaporation increases humidity to an extent. If you’ve ever been in a greenhouse or a tropical plant exhibit, you can feel the humidity as you walk inside.

When the water that travels through a plant reaches a plant’s leaves, it seeps through tiny pores on the underside of the leaves. By hanging out there, the vapor adds to the relative humidity of the air close to the leaf. Kick up the wind, and the leaf moves around, so that it spends time in drier air. Of course, if the air outside is humid that day, the wind won’t have as much effect. But how often is it humid around here? Anyway, high wind, combined with low overall humidity and full sun, can rapidly dry out your vegetables or ornamentals before you know it!

xeric wild rose
No wonder so many xeric plants have smaller leaves. Less transpiration occurs and more energy can go into the plant’s health and blooms. I love this Wood’s rose (Rosa woodsii)., also called a wild rose or Fendler’s rose.

Native Plants Adapt

Native plants adapt to soil and climate. So what about succulents? I won’t get into a long biological discussion, mostly because I am not a biologist or botanist. But one reason that succulents often have small leaves and large stems is to reduce transpiration so they can survive in dry, hot deserts. Others, like the aloes, have a different type of epidermal layer that doesn’t allow for rapid transpiration. It’s amazing how well plants adapt to their environments; if only I could adapt to winter…

Aloe leaves
These aloes have larger leaves, but they lose less water to evaporation than do typical plants.

If you have a non-native that takes slightly more water, remember what I said earlier about protection. Place the higher water user where it’s more protected from wind. If it can take some shade, at least in the hottest afternoon sun of summer, that will help too. Check out past posts for more water-saving tips. And these tips apply to growing vegetables and other edibles in wind and high altitude. The good news for us is that our winds calm slightly by summer.

Use Mulch To Conserve Water In Your Garden

When you put away a gallon of paint or the leftovers from dinner, you always cover the container. By sealing the paint can or plastic storage container, you lock in moisture. It keeps your paint from drying out. Same goes for your spaghetti with pesto (not to mention sealing in the “aroma”…).

Your plant roots can benefit from their own covers, and that’s where mulch enters the picture. Much like the top layer of paint in a can, air dries out the soil at ground level. Add wind and heat, and water can evaporate quickly from desert gardens in particular. Mulch helps insulate the soil to keep it cool and minimize evaporation. The layer of mulch also protects the area around the plant’s roots from the forces of nature. In other words, when the rain comes, it won’t pound the ground, eroding dirt away. Instead, it hits the layer of mulch, then trickles down to the ground. Use an organic mulch and each time it rains or you irrigate, the water carries some nutrients for the roots to take into the plant as well. Need more reasons? Mulching cuts down on weeds, and weeds compete with your plants for water. Plus, they are such a pain.

shredded bark mulch
Mulch cools and moistens barberry, photinia and ice plants in Albuquerque, N.M., bed.

To truly insulate and cool plants takes about three to four inches of mulch material. It depends on the type of material you want to use. If the mulch is fine, such as bark cut to smaller than an inch in size, go only about an inch or two deep. The same goes for grass clippings. Your roots also need some air to thrive! So be sure to avoid use of landscape plastic under your mulch in any areas where you will plant. The plastic is great in walkways, but not in your beds or under trees.

When piling mulch around plant or tree roots, cover the entire area to which the roots extend. For trees, you need to go out about as far as the tree’s canopy. And don’t place the mulch all the way up against the trunk of the tree or stem of the plant. Leave a small opening close to the plant.

mulch around tree
Water is less of a concern in this Northeastern garden/iris farm. But I would worry about how closely the mulch comes to this tree trunk.

Mulches also can look attractive and add to landscape design. Be careful about mulches you choose and social media posts with ideas for repurposing materials as mulches. Some are harmful if applied directly to vegetables and other plants or introduce weeds to your garden. And if your helpful neighbor offers fresh chicken or horse manure, remember that you shouldn’t apply it hot. Add it to your compost, and eventually to the vegetable garden.

gravel around yucca
In the desert of Tucson, the rock around this xeric yucca is probably more for looks, erosion control and night-time heat retention.

We’ll break down some types of mulch in a future post, but if in doubt, check with your local extension office or master gardeners.

Earth Day 2015 – We Can All Lead the Way on Water Conservation

Today is Earth Day, and it causes me to pause and reflect on my concerns about our planet. I live in an area of the U.S. that historically has been heavily affected by drought. We might be doing better this week than many parts of the West, but that hasn’t always been the case. And it doesn’t relieve the groundwater situation.

Earth Day 2015
Earth Day 2015. This year’s campaign is about taking the lead.

I also live in an area where people, for the most part, deny climate change. I avoid political discussions, but I love science. Here are a few facts from NASA:

  • The global temperature is up 1.4 degrees Fahrenheit since 1980.
  • Many argue that temperature relates just to regular shifts, and not permanent change, so how about this one: The Arctic ice minimum is declining 13.3 percent each decade.
  • Melting Arctic and land ice have led to the sea level rising 3.19 mm per year.
  • In addition, carbon dioxide levels in the atmosphere are up 400.06 parts per million, and the forest cover is down.
Ruidoso burn scar
Burn scar from massive fire in Ruidoso area a few years ago. This is from the top of the Apache Ski area.

I struggled years ago to explain the phenomenon to a neighbor who used the classic line “So much for global warming” every time we received a late snow or had cool temps on a spring day. The science is complex, but in my mind, it’s intuitive. Less ice at the surface adds to the vicious circle of warming and less melt on land where it’s needed. More water in the ocean increases sea levels, like a bathtub running over. Add cold water to the mix, along with air and water that are warmer because of carbon dioxide in the atmosphere, and you’re going to affect ocean weather patterns.

thermal-imagery-seas
The swirling of sea surface waters is shown in this thermal infrared image from the Suomi NPP spacecraft on April 12, 2015 in an area just southeast of Cape Cod, Mass. The VIIRS sensors can detect slight differences in temperature at a resolution of 375 meters per pixel, and here they are colored – blue for cold, and red for warm. The warm waters of the Gulf Stream meet and mix with the much cooler surface waters from the North Atlantic. An incredibly tight gradient between these two masses of water is especially evident on the left side of the image, where the area of white is very fine between cool and warm. These boundaries are often ecological hot spots, especially for fisheries. Image courtesy of the National Oceanic and Atmospheric Association.

 

I do know that the first quarter of this year was the warmest on record for Earth. I’ll leave the discussions to the experts, though. For now, I know I could do more individually. I could cut down on some waste and recycle more. We’re already trying to grow more of our own food because it’s hard to get fresh vegetables locally. We have a passive solar home, but we could do more to cut down on electricity and natural gas use.

hike along Rio Bonito
My family on a hike we took along the Rio Bonito near Ruidoso one August.

And water, that precious resource. I’ll increase my efforts there as well, trying to capture more rain water during monsoon season. And I’ll try harder inside the house to decrease water use, because every drop adds up. Finally, I’ll continue to research and offer as many practical ideas as I can on saving water in your landscape.

Smart Xeric Strategy: Grow Edible Plants

It’s a trend that was a long time in coming, but edible landscaping is here to stay, and it can be a great xeric landscaping strategy. More than 80 percent of Americans say they have grown edibles, but nearly one-fourth are concerned about irrigation, so incorporating edibles into the garden landscape just makes sense!

I plan to increase some of the space in our rock garden devoted to edibles this year. We already have some great xeric herbs and I love the blooms of our Western sand cherry, which I hope will bear fruit this year. We also get a few rose hips from our native (Fendler) roses.

Apple tree and red bud in full bloom
The red bud looks edible, but only at the bird feeder! The rose bush on the left leaves hips in the late fall. And if that apple tree by the river makes as many apples as it has blooms, we’ll be heading to the farmers’ market!

Use space and save money

Adding a few edibles means we use some of the space and relatively good soil that’s near our kitchen and outdoor dining spaces for a few more herbs and vegetables. I’ll supplement our fenced vegetable garden and try to select critter-proof plants or hope the area is close enough to our patio to shy them away.

Like me, you might want to grow your own edibles for freshness and cost savings. In particular, herbs are much less expensive when grown from seed or cuttings than when you buy them in a store. I’ve used fresh and dried ones from our rock garden all year long. But so many edible plants also add visual interest. I don’t have to tell you how gorgeous lavender can get. And if not cut, rosemary and sage also produce lavender-colored blooms.

Grow xeric herbs

Then, there is the scent. I can hardly walk by thyme or lavender without rubbing my fingers on the leaves. Here’s a list of low-water herbs to add to your garden landscape:

Sage, thyme, rosemary, and lavender (which can be used to flavor dishes or for many aromatic uses). Basil uses a little more water, but recovers well if neglected, as long as you keep it in well-draining soil. Oregano also needs only occasional watering, and though dill can be particular about soil, it also does well with little water. Read more about low-water herbs in my March post.

Add edible shade trees

If you’re looking for a shade tree, why not plant a fruit or nut tree that is native to your region? Instead of watering for the sake of leaves and summer shade, you can water for some juicy apples or peaches.

Chinese apricot tree for edible shade
No shade needed on this spring day, but in summer, we rest from outdoor chores under this established Chinese apricot tree. It was loaded with fruit about three years ago.

We just ordered a few bare-root trees from the Upper Hondo Soil and Water Conservation District. We’ve already planted a pinon tree. Sure, it will be a long time until it rewards us with pine nuts, and we’ll probably always fight the wildlife for them, but it’s a fast-growing native tree in New Mexico and I’m happy to try for a few delicious nuts to add to some basil for pesto! On the way soon are a serviceberry and cherry. The serviceberry is sure to feed the birds, if not us. And our established currant is in full bloom.

currant bush
This low-water currant provides year-round color and edible berries for wildlife and humans.

Consider interspersing a few edibles into your garden landscape and start small. For example, fill containers with edible flowers. Artichokes add interest to the garden;  just be sure to leave those guys plenty of room. If a few of the edibles you choose take a little more water than typical for xeric plants, consider this: Farmers use even more to irrigate their crops and you use no carbon footprint to drive to the store and buy greens when you grow your own in containers or a raised bed in your own garden. Water as much as possible from a rain barrel and feel even better about your edibles!

nasturtium in old washer
Why not fill an empty container (even a salvaged washer) with edible flowers? Nasturtium look pretty in the landscape and on salads.

Also, be sure to consider where you place your edibles. Spinach and lettuce have shallow roots and need cooler, shadier conditions. But avoid adding a crop of edibles under the canopy of a tree, where they’ll compete with the tree’s roots for water. I plan to use an area of our rock garden area to grow more peppers this year, and our southern-facing rock wall serves as a perfect microclimate to add some extra warmth for tomatoes and peppers.

planting edibles in xeric gardens
We recently weeded, turned the dirt, and added mushroom compost to the rock garden soil to prep it for some edibles as soon as frost danger passes.