Tag Archives: Low-water plants

Roses in the Low-Water Garden

Roses are old-fashioned favorites that often remind gardeners of their mothers or grandmothers or of lush gardens in the South, where both water and sun were readily available from nature. But I see fewer roses in gardens now, partly because they’re associated with lots of patience and care, and partly because some of the hybrid roses need more water than a low-water garden can – and should – provide. It’s also strange to picture a tall, hybrid tea rose in the middle of a xeric landscape, although a good landscape designer can always work a small rose garden into your plan if that’s what you desire.

floribunda rose in low-water garden

Friends brought us this floribunda as a housewarming gift and it fits nicely in our xeric rose garden. We watered it the first year, but only a little this spring.

Many shrub-size roses fit in nicely with the look and purpose of a low-water garden. So you can have the scent and many other features of roses, as long as you’re willing to choose the right type of rose. Here are a few to consider:

Species roses. A species rose is basically a wild rose. Several species roses have grown to adapt to drought and other extreme conditions. I have several in my rose garden area, and I know one of them is a Wood’s rose (Rosa Woodsii). It can grow to at least 10 feet and has beautiful pink flowers, followed by hips all fall and winter, which the birds love. Another is a shorter, shrub-style rose that I believe is the Prairie rose (Rosa blanda), with pink flowers that fade to white in the center. The other has deep red flowers. Both have in common large, plentiful thorns and bunches of two-inch flowers in late spring.

woods rose bloom

Close-up of a Wood’s rose bloom. They’re small, but abundant on the plant’s long canes.

rosa blanda species rose

The wild Rosa blanda is only about 18 inches tall.

Native roses. In New Mexico and other Southwestern states, the Arizona Rosewood (Vauquelina californica), which resembles an evergreen oleander in its foliage and shape, or the Apache Plume (Fallugia paradoxica) both have delicate white flowers that resemble roses. The native plants have adapted to the Southwest and attract bees.

apache plume

This Apache plume (with the Wood’s rose in left background) got too dense and full. They are so easy to care for and forgiving when pruned.

Shrubs and groundcovers. Some hybrid roses have been adapted to grow as smaller shrubs and groundcovers. They’ll use less water and take up less space in the landscape. In general, they need less care than other rose types, but have long bloom periods.

Flower Carpet red

Flower Carpet Red from Tesselaar is a spreading groundcover rose that reaches no more than 32 inches high. It’s drought tolerant once established and hardy down to zone 5. Image courtesy of Tesselaar.

In fact, species, native and certain shrub or groundcover roses are all typically easier to care for and relatively disease free. Just give them mostly sun and prune according to recommendations once in early spring. You don’t have to continuously dead-head blooms, and they have adapted to lower water and the changing conditions of high deserts and mountains, so having them in your garden is more water wise. But there are a few disadvantages. The species roses are wild, which means they can sprout new canes or offshoots. The yellow one in our garden has gotten too thick and large, and will need serious pruning next spring; it’s sort of taken over the area and is shading some other plants too much.

species roses

Our rosa blanda, red species rose and taller yellow species rose to the right. It blooms earlier than the others, so we have color from early May through September.

Another disadvantage is that if you love to cut long rose stems to use the blooms in flower arrangements, you won’t enjoy these varieties as much as hybrid tea roses; their stems are typically shorter. However, if you want to walk or sit next to them in your garden and stop to smell them, or simply enjoy the beauty of the plant and blooms, you can have your roses and save water too!

Favorite Low-water Plant: Desert Zinnia

Although it’s a member of the zinnia family, the desert zinnia (Zinnia grandiflora) is remarkably different from the large annual flower we typically think of when we hear of a zinnia. Actually a member of the aster (Asteracaea) family, this tiny perennial is a delicate xeric groundcover or low shrub native to New Mexico, Arizona, Colorado, Kansas, Oklahoma and Texas.

desert zinnia flower

The desert zinnia has a big flower on needle-like leaves. I love how the flower sort of reflects the sun it loves.

Also called prairie zinnia or Rocky Mountain zinnia, the plant blooms in summer and its tiny, needle-like foliage dies back in the frost of winter, resembling dormant grass. But have no fear! The plant is there, and comes back, even spreading. I just brush up the dormant leaves as part of the spring garden clean-up, and new plants already are appearing underneath. You could also gently rake up the spent foliage in larger areas. Clearing off the old leaves exposes the new plants to more sun, which they love.

zinnia grandiflora shadow

This tiny desert zinnia is casting a morning shadow on the rock it grows from.

But although desert zinnia loves sun, it doesn’t love water. That’s right – once established, desert zinnia needs no water at all. Too much water just introduces weeds into the mix, which can be hard to pull from between the delicate foliage. If you have a period of no rain, you can give desert zinnia some water to ensure blooming. The flowers also do fine in partial shade.

desert zinnia in rocks

Desert zinnia will spread low across the ground or cascade down rocks. This weekend starts monsoon season, and I expect more blooms to appear.

Typically, the desert zinnia is about 4 inches high and spreads to nearly 15 inches wide. Each flower can reach nearly an inch in diameter, with an orange cone (Golden Eye) surrounded by three to six yellow petals. It should thrive in zones 5 through 8. It’s a great plant for erosion control and for rock gardens. I love how it cascades over and through our rock wall.

Garden Project: Harvesting Lavender

Lavender is without a doubt my favorite drought-tolerant plant. Aside from its stunning appearance in the garden, it’s a fragrant herb. We added 15 lavender plants to our garden last year, and some of them failed to make it, mostly because of unseasonably cool and moist spring weather. But most of the survivors are now thriving and we have plans to expand our lavender “operation,” because once you get it started, it’s just so darn easy to grow.

lavender blooms

Close-up of Hidcote Superior English Lavender blooms. The stems of ours did not get very long, but I believe it will do better next year. I love the deep purple color.

If you cut off the first blooms of the season, lavender plants reward you with another late-season show. Yesterday, I decided to harvest some of the flowering buds to dry them for possible potpourris, bundles, and other gifts and to encourage the second wave of blooms. It was great fun!

To experiment with drying stems, buds and leaves, I cut some short stalks from newer plants that were not long enough to dry as bundles. They’ll make great potpourri or sachets, assuming I am smart and industrious enough to figure out how. I included a pretty established white lavender that’s been in the garden for years.

tools used to harvest lavender

Tools for my first attempt at lavender harvesting: our notebook with records of lavender planting, rubber bands, large paper clips opened up, and tags to mark bundles.

Some of the stems are too short to hang and I don’t want to waste any buds that might fall. I’ve heard of using paper bags, and remembered I could never bring myself to throw out the bags my espresso beans come in. They were the perfect size and already have a sturdy top that’s easy to close and hook onto for hanging. I cut holes in the sides of the bags for ventilation and marked the plant and date on the bag. One concern I have is that the bags still smell (deliciously) like coffee, so I wonder if the lavender inside will blend with that aroma. Worst case? Lavender lattes! Seriously, I might try it.

But I really love the look of dried stem bundles, and six of our one-year-old plants have produced a good crop of long stems. I went ahead and harvested stems from one of them. The trick to gathering long stems is this: You want the length to maximize the look and aroma, so it helps to cut all the way down to the plant’s round shape of existing foliage. But I realized after cutting that I removed many tiny, new flower buds down the stem. That might affect the number of blooms in the second round. We’ll see how the late-summer bloom on this plant compares with the next one I harvest.

xeric English lavender

One-year-old Royal Velvet English lavender blooming away in a xeric garden. There are two more next to it. The other purple to the left is from volunteer Larkspur.

lavender after stems harvested

Same plant after I harvested all of the stems. In retrospect, I should have left some on the plant that hadn’t quite opened. But I guess the symmetry before and after appeals to me more. I even trimmed it to make it nice and round again.

Out of one (one-year-old) Royal Velvet English Lavender, I was able to make a respectably sized bundle and a smaller bundle to take to friends I was having a picnic with that later in the day. I also stripped some of the leaves and tiny buds from down the stem and placed them in a coffee bag for even more yield from the plant.

lavender harvest

Here’s my yield for the day: a long and short stem from the Royal velvet plant, plus a bag of “remnants,” a bag of white lavender buds, and one bag each from the Hidcote and a young Munstead, both too short to bundle but just as aromatic.

The day before, I had hammered several nails into the beams of our old shed. It’s dry and has good ventilation. It’s not completely dark, which might be the drawback. I used rubber bands to hold the bundle together, and opened up large paper clips to secure the rubber band or the bag tops to the nail. I also slipped a small piece of cut-up old business cards into the bundle’s rubber band with the plant and date and hung it upside down. They should take about a week to dry.

drying lavender in shed

I knew this shed would be good for more than storage! All it took was nails, paper clips and coffee bags.

Low-Water Shade Trees

A well-planned xeric landscape can include a few low- or medium-water shade trees, especially when the trees are native to the area. Trees naturally use more water than small shrubs, but offer several advantages that make up for it, including:

Providing shade for houses and patios to cut energy use in summer. Choosing a deciduous (instead of an evergreen) tree means you’ll only shade windows in summer, and leave them open to sun in the winter to provide solar gain for warming your home. Trees that drop leaves in winter work best at shading your house when planted on the home’s southwest corner.

chinese-apricot for shade

Nothing beats a shade tree in summer for plants and gardeners. This established Chinese apricot on the southwest corner or our home shades the patio, garden and some rooms and windows. We hope it provides fruit soon.

Trees also can shade other plants, helping to keep roots cool and moist, which saves some water in the landscape and opens up your ornamental or edible plant choices.

Place shade trees close enough to your house that you’ll receive some of the energy savings and comfort of the shade, keeping in mind the tree’s mature size and the direction of summer sun and shade.

Here are a few low-to-medium trees that can provide shade and interest to a xeric landscape:

Desert willow (Chilopsis linearis) is a striking, rainwater-only tree once established. Its shrubby, slightly smaller shape might be less effective at shading large areas or for providing cover for a picnic table, but it grows quickly the first few years. In fact, if you overwater it, the trunks grow too quickly and are susceptible to breakage from the wind. The orchid-like flowers attract hummingbirds. The sun lover may leaf out after other trees in spring, so don’t worry. It can reach heights of 20 feet and grows in zones 7 through 9.

desert willow

The desert willow has delicate leaves and orchid-like flowers. It will leave seed pods, but I’ve never found them to be messy.

Catalpa (Catalpa speciosa) has large, oval leaves and showy, almost tubular flowers. The tree can take heat and low to medium water. It grows to a height of about 60 feet in zones 4 through 8. Just beware of the Chitalpa (X Chitalpa taskentensis), a hybrid cross of the catalpa and the desert willow. Its flowers are gorgeous and it’s fuller than the desert willow, but the plant is prone to a bacterial disease.

catalpa leaves and flowers

Close-up of catalpa leaves and flowers. Image by G. F. Russell and courtesy of the Smithsonian Plant Image Collection.

Velvet mesquite (Prosopis velutina) is a low-water shade tree that also leafs out late in spring, and rewards with sweet-smelling yellow flowers. It can reach 30 feet tall and 25 feet wide and is more cold hardy than some low-water choices, down to 5 degrees Fahrenheit. All of the mesquites are low-water users, surviving in the driest conditions.

Smoke tree (Cotinus coggyria) can take low-water conditions once established, but might require more water during hot summer months and while flowering. The flowers give the smoke tree its name; they’re feathery seedheads that burst open in summer. The foliage is just as attractive, though, with both green and purple colors, and a fall gold. The tree will only reach about 15 feet high, but it’s a great choice for xeric landscapes.

established smoke tree

Large smoke tree in full bloom at the Hondo Iris Farm in New Mexico.

smoke tree leaves and blooms

Smoke tree leaves and bloom. The leaves change color throughout the year and the blooms do have a smoky scent.

Blue spruce (Picea pungens). Most evergreens, except Junipers, require at least medium water. I can’t bring myself to recommend Junipers because of their allergenic potential. But you’re welcome to read about junipers elsewhere. The blue spruce is meant for cooler climates (Zones 3 through 6) and can grow to 50 feet. It comes in smaller cultivars that can survive at lower elevations and work better in a small yard or xeric landscape without taking over.

blue spruce tree

The regal-looking blue spruce, an evergreen choice for cooler climates. Image from North Dakota Extension Service and USDA Plant Database.

For an edible choice, try the Jujube (Zizyphus jujuba). Once established, it only needs a deep watering once a month. The tree also is called the Chinese date because it bears a sweet/sour date-like fruit for birds or people. The tree tends to spread and form groves, so it’s great for shade and wind screens. It can reach a height of 20 or 30 feet, however.

Perennial or Annual?

Gardeners often face the choice of filling a container or a space in their xeric landscape with either an annual or perennial. And new gardeners might have a hard time knowing whether a plant they spot and love will come back in their garden next year. Let’s take a look at annuals vs. perennials, especially in xeric landscaping.

cosmos and agave in New Mexico garden

These agave are xeric, but apparently so are these cosmos, annuals that just pop up from old seeds each year, to the point we had to thin them to give the agave room.

First-time gardeners might not get the difference between the plant types. It’s easy to remember if you think about the terms attached to each plant: A perennial lasts three years or more, but an annual is there only for this year, just like the root of the word (annus, Latin for year).

So, how do you know when you want a perennial and when you want an annual? Here are a few scenarios:

For containers, it’s often best to go with annuals. Unless you have plenty of sunny indoor space and a strong back, you’re better off placing annual flowers into most of your containers, just for the season. Of course, succulents can easily live indoors in sunny locations, as can some herbs, bedding plants and houseplants. I love planting just a few containers each year in front of my house, and at our last home, we had one annual bed that we changed out each year, also adding pansies for winter color. It’s a small splurge.

But if you’ve got a huge raised bed to fill, go with bulbs and perennials, or maybe spring-blooming bulbs, overplanted with annual seeds that come up later in summer, after your bulbs are done blooming. Seeds cost less if you’re willing to wait for the plant to grow, then bloom. Having said that, one of the benefits of buying annual plants is instant gratification!

xeric annuals and perennials

I think I just showed the combination of yarrow and gaillardia, but I can’t get over how great the perennial and annual look together.

Here are some of my favorite low-water annuals, many of which are wildflowers that will reseed:

  • California poppy
  • Cosmos
  • Desert marigold
  • Portulaca (Moss rose)

For most xeric gardens, however, you can’t beat a hardy, low-water perennial that blooms year after year. All you usually have to do is cut back dead branches or flower stems and wait. A few cautions with perennials: Some spread, even though they’re xeric plants. And sometimes, you have to cut them back drastically to keep your garden under control and prevent one perennial from competing too much with others, such as shading another plant that needs six hours of sun a day.

gray santolina and cherry sage

This gray santolina. along with a few neighboring perennials, is blocking sun to the red sage next to it. I love both plants, so we might move the sage to a sunnier location.

Here are a few of my favorite low-water perennials:

  • Coreopsis
  • Echinacea, or coneflower
  • Gaura
  • Lavender
  • Penstemon
  • Sedum
  • Santolina
  • Sage – any perennial salvia and sage
  • Yarrow

How do you tell an annual from a perennial when making a purchase? If your nursery doesn’t have the plants sorted by annuals vs. perennials, you can always ask. Another clue is that many annuals are sold in six-packs or similar packaging for several smaller plants. Perennials tend to come in pint size, gallon pots and up. But that’s not always the case. And a particular flower might be available as both, so check the tag or ask nursery staff. An example is the salvia, which comes as several great perennials. But there is a red salvia that only works as an annual, at least in my zone.

larkspur annual

Pink and purple larkspur, the annual version of Delphinium. These reseed under our red bud each year with no effort on our part.

That takes me to my final point: One gardener’s perennial might be another gardener’s annual. In other words, zone and general conditions can alter a plant’s ability to endure for more than one season. Geraniums are container plants or annuals in the mountains and high desert of New Mexico, but might be perennial in southern California. And just to add to the confusion, hardy geraniums (of the genus Geranium), are different from Pelargoniums, common geraniums, such as the scented flowers. And gaillardia, or blanket flower, is one of my favorite plants that might be an annual or perennial, depending on the cultivar and conditions. Ours simply reseed throughout the garden year after year.

I added several other photos of annuals and perennials mentioned in this post to the Photos page.

Start Small on Your Xeric Landscape

If you’re not an experienced gardener or feel overwhelmed by the prospect of starting a landscape from scratch or switching your entire landscape to a xeric one, why not start small?

Time, money and inexperience should not keep gardeners from enjoying a few plants in their yard. I sometimes can’t stop bemoaning the trend in believing that xeriscaping is the same as “zeroscaping.” Again, it’s not!

Even new, young gardeners and urban dwellers can enjoy a few blooms or edibles without busting their budgets, schedules or water resources. Try these tips:

  • Start with containers. If you have little space, but crave fresh herbs, enjoy a few bright blooms next to you while you savor your morning coffee outside. Or enjoy the view of hummingbirds hovering over a flower by outfitting your patio or balcony with a few brilliant containers. You could add a long, thin box with your favorite low-water kitchen herbs and a tall, round container with a salvia for color and pollinator interest. Or try a geranium, which uses a little more water, but lasts year-round in your container if you bring it indoors to a sunny location.
mint and lettuce containers

Mint in a container — where it belongs! Friends gave us these two transplants. That’s a baby mesclun lettuce mix to the right.

  • Take it one area or bed at a time. If the idea of going completely xeric in your garden is too much to handle at once, take baby steps. Convert a small area of your lawn from grass to gravel and native plants, or from high-water grass to native grass, gravel and native plantings. Or take out grass along a sidewalk or driveway and create a path with a few ornamental grasses and perennials. An easy way to conserve water is to divert rain from a downspout that pours onto, say, a driveway so that the water instead flows to a tree already in your landscape. Find plans for dry river beds with rocks to ensure the water flows to your tree.
  • Choose one or two hardy xeric perennials a year. I’m not the best person to advise patience, but if you’re short on budget and time, choose just a few hardy xeric plants to start your garden off right. The best choices depend on where you live and your USDA zone, along with the microclimate for the location you plan for the plant. Choose a perennial, a plant that will live through your winter and bloom again for at least two years. If this is an early attempt at gardening for you, go to a local nursery, where the staff can show you a few natives for your area that are hardy and easier to grow. Then go by size, bloom color, water and sun needs, maybe overall care (like deadheading) and your general reaction to the plant. There’s nothing wrong with choosing two of the same plant if you love it. Repetition can be just as attractive in a xeric landscape as complementing textures and colors!
dianthus perennial

This Dianthus next to our bird fountain needs little care and no supplemental watering, but comes back each year. In fact, a new plant showed up in another bed about 15 feet from this one.

  • Buy seeds instead of annual plants. This early in the year, at least in most zones, you still can have plenty of success with seeds for annuals to complement your perennials. There are tons of great xeric wildflower choices that grow from seeds, saving you lots of money. Instead of buying several six-packs of petunias or marigolds, pick up a seed packet of cosmos, zinnias, poppies or a native wildflower mix. Seeds need more attention and watering at first, but the flowers usually reseed for several years. And even though seeds in packet eventually expire, we’ve had success with old flower seeds.
blue flax

I can see this stunning blue flax (Linum lewisii) from my office. The damp spot on the ground is an area of red flax seeds we sowed.

Of course, if you can go big, do it. There are plenty of professionals, books and sites dedicated to xeric landscaping.

Low-water Plants that Hummingbirds Love

As soon as hummingbirds start buzzing around the garden, many locals put out their feeders. I have tried one this year, only because I had few plants blooming when the hummers arrived. I prefer to feed the hummingbirds with natural plants because of time, mess and the fact that native plants seem healthier for the birds and way more fun for us!

hummingbird on agastache

Hummingbird on agastache in our garden in 2013. Photo by David Higgins.

There are many rules about hummingbird food safety, and I worry I will forget, be gone, etc. But there are so many plants hummingbirds love that we already have in our garden or can add to attract more birds. We especially love to watch the male hummers’ courtship dives from our back patio, and I am certain that a few male birds have claimed our rock garden, or some portion of it, as their territory each summer.

To naturally attract hummingbirds and enjoy the same plants they use as nourishment, choose plants with brightly colored and tubular flowers. Hummingbirds are attracted by color, not scent. Red is their favorite, but purple, yellow, orange and pink also bring them to plants. And in addition to tubular flowers, try plants with blooms that nod, or bend downward slightly. Of course, continuous blooming also helps.

Here are a few xeric hummingbird favorites:

Agastache (Agastache cana). This xeric rare wildflower has bright pink flowers on upright stems all summer, and some, such as Texas hummingbird mint, are aromatic as a bonus for humans. There are other many variations of agastache, also called hyssop, in varying purples, oranges, pinks and reds, that attract hummingbirds with their slender, tubular flowers.

agastache cana

Agasatache cana Sinning, also called Sunset Sonora Hyssop is a compact Agastache cana from Plant Select. Image is by Diana Reavis and from Plant Select.

Butterfly bush (Buddleia). Butterflies share this purple-flowered favorite with hummingbirds. The spiked flowers appear at the end of the branches and can be from eight to more than 12 inches long.

Autumn or cherry sage (Salvia gregii). The salvia has bright pink, raspberry-colored flowers on a low bush all summer long. The low- to medium- water plant can grow in nearly any soil.

salvia gregii

Two cherry or autumn sages in a rock garden, just coming into bloom. Hummingbirds love the bright pink flowers.

Desert willow (Chilopsis linearis). This is the tree I miss the most since moving to a colder zone, although I might try it here soon. The beautiful xeric tree can be trained to grow wild and bushy or more tree-like. But its charm to hummingbirds and humans is the large tubular flowers that come in light and dark pink colors.

desert willow flowers

Hummingbirds love the orchid-like flowers of the xeric Desert willow, or Chilopsis. Image by R.A. Howard © Smithsonian Institution, Richard A. Howard Photograph Collection.

Other hummingbird favorites that might grow in the mountains, high deserts and xeric landscape that attract hummingbirds are some types of columbine, some bulbs, such as Crocosmia, and every variety of penstemon. And I imagine you can’t go wrong with a plant I have never tried, but is aptly named “Hummingbird Plant” (Zauschneria Californica), a medium-water, full-sun plant that has scarlet-orange flowers. It will require extra watering for a year or two until established, but grows to more than two feet in height.

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.

Favorite Xeric Plant: Penstemon

The hummingbirds are swooping around the garden, and soon they will enjoy feeding off several water-wise Penstemon species. The penstemon, also called beardtongue, is a versatile low-water native plant in New Mexico and the Southwest.

In fact, penstemon does best with no added water at all. And the plants can thrive in full sun or light shade. Penstemon comes in a variety of sizes, shapes and bloom colors. But they have in common a slender trumpet-shaped flower that hummingbirds love.

purple penstemon

Hummingbirds love penstemon flowers, but can you also spot the bees in this photo?

Caring for penstemon

Penstemons usually prefer somewhat sandy or clay soil, and don’t need added compost. Most species of penstemon are perennial in our zone (6 to 7), but some are annuals. They’ll bloom from summer to frost. Species such as Arabesque Red bloom from summer through first frost with deadheading. However, if you leave some blooms on the plant, the seedheads ripen and break, which causes the plants to reseed. We’ve had several volunteers come up in our rock garden. And birds love the seeds!

red penstemon AAS regional winner

Arabesque Red was the regional winner (including the Mountain and Southwest regions) fof the All-America Selections in 2014. Photo courtesy of the National Garden Bureau, Inc.

The only way to really harm penstemon is to overwater or overnourish this easy-care plant. Use fine gravel for mulch. Occasionally, aphids gather on the stems, but you can use a fine mist of water to spray them off in the morning and check a few days later.

Penstemon can work well in containers, especially if you select a lower-growing variety. Select low-water companion plants, so that the penstemon does not receive too much water. If it does, it can become leggy. You might find that a penstemon in a clay pot needs occasional watering compared with one in your landscape.

In a xeric landscape

Penstemons are great plants for xeric landscapes. Low growers such as Desert beardtongue (P. pseudospectabilis) spread to about 15 inches wide and 30 inches high, with purple-maroon flowers on stalks above the blue-green foliage. The pineleaf penstemon (P. pinifolius) is a native wildflower with tiny needle-like leaves and bright orange-scarlet flowers. I love watching the hummingbirds maneuver effortlessly into the flowers.

pineleaf penstemon

Our pineleaf penstemon hasn’t flowered yet, but it’s still attractive, with the pine-like foliage and its low spreading nature.

A taller, lankier type such as Rocky Mountain beardtongue (P. strictus) looks gorgeous against a fence, wall or tall rock. Its purple flowers contrast nicely with yellow or white bloomers in the foreground. The bushier pineleaf or Desert beardtongues are perfect to tuck in a corner, or along a step or walkway.

desert beardtongue penstemon

The Desert Beardtongue is a 2015 Plant Select winner. Photo by Bill Adams and courtesy of Plant Select.

No matter which variety of penstemon you choose, you’ll be rewarded by hummingbird guests and the beautiful blooms that appear with very little care on your part!

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.