Favorite Xeric Plant: Ornamental Grass

When xeriscaping, you can add plenty of interest with varied textures and heights by including a few ornamental grasses in your landscape. We’re always tempted to think first about flower color, but less about interesting foliage. Placing a few ornamental grasses in a xeric landscape or container can add nearly as much impact as a pop of purple with less watering and maintenance.

Choose an ornamental grass that is native to your area, or a similar climate or condition, in place of a shrub or perennial flower. One of my favorite features of grasses is that they can grow tall and move in the wind. In containers, they often add height or contrast to draping and flowering annuals. Warm-season grasses seed out and provide winter interest, even if the foliage browns. They need shearing once a year in spring, a little water to jumpstart growth, and they’re off. If you choose one that’s not native to your area, such as the big-box store selection I found for my containers, make sure it can at least survive with less water or other conditions that differ. You might not get flowers or as much growth, but the grass will survive at least for the summer.

rush grass in container
I like to place ornamental grasses in container arrangements to add height and texture. This juncus is all I need to add interest to a petunia mix and continuity between the pots.

Another benefit of ornamental grasses is that they can serve practical purposes in a garden. Use them for erosion control by placing a small grouping at the bottom of a slope or terrace – and go for a medium-water selection such as Feather reed grass “Karl Foerster” (Calamagrostis arundinacea) here, since the rain or irrigation run-off from above supplies the extra water the plant requires.

feather reed grass
Karl Foerster feather reed grass that was planted a few weeks ago in our rock garden . It already looks great, but will add feathery blooms in summer. It should survive our winter (zones 5 and 6).

Other great locations for grasses are along steps, pathways or corners, in front of dark walls or fences, and anywhere they will catch sunlight and breezes.

Sedges, rushes and some hardy bamboos also fall into the ornamental grass category when landscaping. Just be sure to check the zone, native location of the plant, and especially the sun and water requirements before planting the grass. Some actually do better in marshes – not a good choice for xeriscaping!

Easy care

Grasses are among the easiest xeric plants you can have in your garden. They’re mostly free of pests and diseases. And although I love ornamental grasses, I have seen some gardens with only grasses and gravel. I think you need one or two other xeric plants to break up the look, but I’m not a professional landscaper. To my eye, just gravel and grass in a garden screams “dry!” It’ so easy to complement a low-water grass with a salvia, penstemon or gayfeather.

Some cool-season grasses bolt in the heat, but trimming off their seedheads can rejuvenate the plant, much like clipping off flowers of herbs to force growth back into leaves. Most ornamental grasses are warm-season selections, best planted in the spring. They need a little more water, up to once a week for xeric choices, for the first month or two. After that, water deeply only every few weeks or once a month in the hottest summer weeks. Some will spread, and it’s best to try to divide or dig up unwanted volunteers before they clump too tightly. Other than that, just cut back as directed. Allowing several grasses to overseed in winter could add to your fire hazard, so keep that in mind if you have them near your home or a commercial building.

big bluestem grass before strawbale wall
Newly constructed strawbale wall with xeric plantings. The big bluestem grass on the right foreground got much taller and flowered (see below).

A few xeric grasses

Silky threadgrass (Stipa tennuifolia). This hardy grass grows in all types of soil, uses little water, and loves full sun. That’s a bonus, since the silky seedheads reflect sunlight as they sway in the breeze. One caution for silky threadgrass is its high potential to reseed. That’s a plus in an untamed garden, but not in a more formal xeric landscape.

Big bluestem (Andropogon gerardii).  This is one of our personal favorites. It can reach heights of four to five feet in summer, when it also rewards you with purplish flower spikes that emerge between the beautiful greenish-blue leaves. Some selections require more water than others, so check with the nursery or on the tag for details. Some are highly drought tolerant and thrive down to zone 4.

big bluestem flower heads
The flower stalks of big bluestem grass are purplish, contrasting well with the greenish-blue leaves.

Dwarf fountain grass (Pennisteum alopecuroides). Purple fountain grass (P. setaceum) is a particular favorite of these dwarf varieties, but only makes it as an annual in our zones (5 through 7). Others fare better, although an unusually cold winter could kill them. Most have bright green foliage with bottlebrush flowers. Examples are “Hamelin,” a compact, mounding variety with ivory and gold flowers and “Moudry,” which has brownish-black flowers. One caution: You might have to protect dwarf fountain grasses from rabbits if they visit your xeric garden.

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.

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.

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.

Low-water Use Tips To Meet Restrictions and Good Water Sense

We spend a lot of time talking about xeric plants, and recently posted some tips on low-water use for gardeners. California has implemented emergency regulations to conserve water during their drought, and the ones related to landscaping are the sort of common sense practices that xeric-minded organizations and gardeners have always touted:

  • Avoid runoff when irrigating.
  • Don’t irrigate during or 48 hours after measurable precipitation.

This post goes into more details on the restrictions, which, along with scheduled days or times of watering, are pretty common municipal regulations in drought-stricken areas.

Avoid runoff when irrigating

Runoff obviously can come from too much water. Of course, good planning of landscape, plant selection and irrigation choices upfront can prevent runoff. Correct an existing problem by first checking the area after the system runs. If you normally water while at work, do a manual run so you can test your system on the weekend. If you have runoff, study where flow occurs. If it’s down a slope, consider terracing the lawn area or welling around the tree or shrubs that you’re watering. You can also cut watering time, of course. If you’re worried about one tree or ornamental that needs more water, cut the irrigation system watering time and supplement the tree’s water every once in a while with a hose or bucket. Don’t waste all of that water irrigating concrete or pavement, and possibly weeds, just to keep one plant healthy. For a small lawn or several plants on a drip system, you can decrease watering time and increase frequency if necessary.

terraced lawn to prevent sprinkler runoff
This Albuquerque lawn has some bermuda grass, but notice the terrace to avoid runoff. Also, note the exposed drip lines being reset in the xeric garden area on lower right.

The runoff might be from a misdirected, leaky, plugged or defective head or emitter. It’s easy to turn and redirect the head so the water goes where it should. A small leak in the system can waste hundreds of gallons of water. Plugged sprinkler heads are a common cause of pooled or misdirected water. Running a stiff wire, such as a straightened paper clip, through the emitter hole can clear some debris. If the entire head is full or dirt or grass, you can turn off your system, lift and unscrew the head, soak it and use a small wire brush to clean it. Then rinse it and screw it back on.

Avoid watering a wet lawn

This should be a no-brainer, but I already ranted in my previous post about neighbors who left their automatic sprinklers on no matter the weather. My best advice is to set automatic sprinklers to “manual” and water regularly but only as needed based on weather conditions. You can set a reminder on your smartphone or other device to jog your memory if that’s a concern. But it’s sometimes more difficult to remember to override the automatic setting on the sprinkler, especially if you’re not there to do it! Otherwise, pay attention to the weather forecast each evening and override the auto setting when rain is predicted the night before so you don’t have to add the task to your busy morning schedule. You can always water a little in early evening or the next morning if the forecast is off the mark.

Of course, if you’ve switched out some or all of your turf for a xeric landscape, at least you are using less water. It also means less need for an automatic system. Most xeric plants need such infrequent watering that you’re best served by a manual irrigation system or the totally manual system of carrying a water bucket from your rain barrel only to the plants that need a little more water — and only when they need it!

raised ornamental bed bubblers
We raised part of this bed and replaced spray heads with bubblers to conserve water.

Other water-saving tips

  • Water early in the morning, especially if you live in a hot climate. Your plants take up more water before the stressful heat of the day, and if you’re using spray irrigation, less water evaporates.
  • Use drip irrigation when possible instead of sprays and sprinklers, or at least keep the spray as low as possible. Spraying water can lead to some leaf diseases, and you want most of the water to go into the plant’s roots, not into the air.
  • Well around plants, especially new plants, any plant that needs more water than others, and anything planted on a slope to trap the water.
  • Choose xeric, low-water and native plants.
  • Use mulch as appropriate to help keep plants cool and roots damp.

    welled shrubs
    Wells around shrubs at Tucson area nonprofit

Of course, it never hurts to call in a professional landscaper or other pro to get some help with your irrigation system or to better plan your lawn and garden for low-water use. For example, avoiding steep slopes in your landscape (with terraces and other strategies) can prevent water runoff, and use of microclimates can increase plant viability while decreasing water needs.

Xeric Garden Zones

If you’re planning a xeric garden for spring, and especially if you’re planning to take out a grass lawn and replace it with gravel and xeric plants, try planning your garden in recommended water zones.

First, let me jump on my gravel soap box. I’ve said it before and I’ll say it every chance I get: Ripping out grass and replacing it all with gravel represents many homeowners’ idea of xeric gardening. They soon find out that it’s not the best solution when a tree left in the middle of a gravel lawn dies and their home cooling bill skyrockets.

gravel yard
A typical gravel lawn misnamed as xeriscaping. Note the grass creeping up between the gravel, but that’s a future topic.

So let’s consider zones instead.

Arid Zone

You’ll want your most arid zone farthest from your house. Choose native plants that need the least amount of water, hopefully no supplemental watering at all. Here in New Mexico, that might include cacti, yuccas and many varieties of native flowering plants like Kniphofia uvaria (Red hot poker) or Berlandiera lyrata (Chocolate flower). It all depends on your landscape and personal preference.

Cacti-gravel
Cacti can add texture, height, blooms and plenty of interest to an arid zone.

Transition or Middle Zone

Your next zone can blend some lush, medium water areas with drier ones. Here’ you’ll use plants that take low and medium water. They only need water beyond nature’s supply about once a week or less. It’s a great spot for medium-water shrubs and trees, such as Spartium Junceum (Spanish broom) and various native oaks to provide summer shade, but let winter sun shine through.

This lawn is not a perfect depiction of the transition and mini-oasis, but it shows the arid zone with low-water plants, and a Bermuda lawn. Note the unhealthy cypress, planted years ago.
This lawn is not a perfect depiction of the transition and mini-oasis, but it shows the arid zone with low-water plants, and a Bermuda lawn.

Mini-oasis Zone

If you want to keep some grass, here’s your chance. Drought-tolerant grasses like Bermuda, Blue Grama, or Buffalograss need little watering but keep your lawn green and other plant roots cool. When used in moderation, and not to cover huge areas, they’re still low- to medium-water choices for this zone. Add some annual flowers in beds or containers up close to the house. By placing lusher plants and turf that need a little more water closer to your home, you help cool your house and take advantage of water runoff from the roof and downspouts.

xeric landscaping zones
A simple example of xeric water zones.

Of course, the drawing simplifies the concept. Landscapers who understand xeriscaping concepts know how to make your zones appealing and customized for your tastes and gardening ability. And by using microclimates, mulching, welling and other waterwise concepts we’ve discussed in other posts, you can push the limits in some of the zones. The basic concepts are to keep from overusing water and avoiding undermining the health of existing trees, along with the comfort and appearance of your home.