A few months ago, I mentioned how many garden books we have on our shelves. I just added a new resource from our favorite local expert and fellow member of the Garden Writers Association, Judith Phillips.
Judith’s newest release, titled “Growing the Southwest Garden,” (Timber Press Inc., 2015) is a go-to guide for native and xeric plants for New Mexico, Arizona, and our neighboring states’ high deserts. It’s also a beautifully written discourse on the climate extremes faced by the gardeners who live there, and especially by the plants they care for.
Judith, a landscape designer, author and part-time professor, describes how and why climate affects plant selection and health and why it’s so important to base landscape design and plant choice on region. She explains the scientific basis of heat, drought, wind and other stresses on plants and how native plants have adapted to the extremes the Southwest deserts and mountains offer. In addition, Judith offers plenty of ideas and strategies for successful gardening in the various regions of the Southwest.
The book includes examples of landscape designs, an excellent list of Southwest plants and more than 300 color photos. The information is both practical, with tips on seasonal pests, for example, and thought provoking. As one of our top proponents of preserving water and ecosystems, Judith reminds us all how to tend our gardens, create practical but beautiful landscapes, and protect plants and other living beings.
What I love most about this book is that I will read it again and again, not just as a brief reference to look up a plant, but when I start to lose faith. Sometimes, gardening in climate extremes can be frustrating, and it helps to be armed with knowledge and tools. As a near-native of the Southwest, who grew up in the scorching heat of Phoenix and since lived in the mountains of northern New Mexico and the high desert of southeastern New Mexico, this book reminds me to embrace all that I love about the Southwest, its terrain and native plants.
I have found Growing the Southwest Garden available from Timber Press, on Amazon and at the independent bookstore, BookWorks, in Albuquerque, N.M.
A month ago, I talked about how strategic use of rocks and other natural hardscaping could add interest to your xeric garden. Another strategy, and a fun activity, is careful placement of art in the xeric garden.
With small objects of art, you can treat your garden like a canvas to add focal points of interest for times when plants are not blooming, to bring the eye up or down as a complement to plant height, to add pops of color or movement, or just to add some fun and whimsy.
Although many of the objects in our garden have been gifts from family members, we also have enjoyed picking up a few pieces of art when traveling. That way, we have a souvenir from our trip, and we get to see it nearly every day in one of our favorite places.
Of course, there is some magnificent art you can purchase, such as fountains carved from natural stone. And you will see excellent specimens in your favorite home design and fine gardening magazines. If you have a tighter budget and like to collect your own small objects, it’s really a matter of personal taste when deciding what goes into your garden. And although I am not a landscape designer, here are a few tips:
For xeric gardens, art made from natural materials typically fits in better. Objects made from metal, wood or stone and with earthy finishes usually fit into the flow better. However, a few bursts of color can really add to the garden’s palette. For example, there is a piece of garden sculpture at one of our favorite shops in nearby Cloudcroft, N.M., called Off the Beaten Path, that I’m coveting. It’s an army helmet made into a bright red ladybug. And one of these days, it will have a place of honor among the green of our garden. Unless they sell them all before I can get one!
With color or garden art in general, too much of a good thing can be a bad thing. In other words, I have seen it overdone. Still, if you get joy from collecting or making garden art, then go for it. After all, this is your garden, your sanctuary.
When placing art, consider plants’ growth. If you have a large object that you can’t easily move, be sure not to place it so close to a small shrub that the art eventually disappears. I’ve pulled up plenty of annuals and weeds because they choked out a favorite little sculpture.
Combine form and function. Decorative rain gauges, bird houses, bird baths, bird feeders, butterfly water trays, wind spinners or weather vanes all can serve a purpose in your garden and provide visual interest.
Really, the sky’s the limit, especially if you are into repurposing old items. A larger garden can hold a recycled gate or window with your own idea for a stained glass design added by a local artist, or you can create a small bottle tree.
With strategically placed garden art, you can add year-round interest to your xeric garden without the need to add more or larger plantings.
If one of your concerns about xeriscaping is that your garden will look as barren as the Southwest desert, it only takes a little planning and time to ensure you have some color and texture from spring to fall. Of course, that’s easy if you have unlimited water and time.
But it’s also entirely possible and relatively simple to have continuous color using low-water plants. Here are a few suggestions:
Don’t give up on bulbs. Although you would think they use lots of water, they’re like the camels of the plant world, adapted or bred to store water and energy in their roots, stems or leaves. They also do best in well-draining soil. I’m lumping corms, tubers and rhizomes with true bulbs. Spring-flowering bulbs should need no water other than rain after established unless you have a really long dry spell, especially during growth and flowering. As long as you choose varieties recommended for your area and follow care guides for placement, mulching and dividing, you should be able to add bulbs to your xeric garden as desired. I love how iris and tulips bloom early as a sign of spring.
Choose one or two continuous, or nearly continuous, bloomers. I don’t know how a small shrub, especially a xeric one, can bloom in the late spring or early summer and hold those blooms all season. But I think the easiest way to plan a small xeric garden is to select one continuous bloomer you like, then build around it. For example, santolina usually blooms all summer, after one trim or shearing back in the spring. Since it has yellow flowers, you can then decide how you’d like to complement the low spreading shrub with other colors throughout the summer. By the way, it’s also evergreen, so you can consider how to complement the gray (silvery foliage) or green santolina with another evergreen or some hardscaping for winter interest. Other examples, depending on your zone, are gaura (Gaura linheimeri) or most salvias, though some might require deadheading.
Try a groundcover. You don’t have to replace your entire lawn with a groundcover, but you can add color with some well-placed xeric planting. Several thyme varieties require no water at all and are terrific at filling in spaces between pavers, rocks or stepping stones. You’ll get some green and tiny purple flowers when they bloom. A groundcover also can cool the roots of other plants that need a little help to survive hot summer days. Just remember that they spread, especially if you overwater them.
Supplement with a few annual seeds or containers. Satisfy your desire for early color and bloom variety each year with some annuals. Seeds are inexpensive, but are a little more water and time intensive. Or fill a designated area of your patio, deck or garden with a few containers with pops of color from annual bedding plants. You can decide when the color appears and what colors you want to complement your perennial blooms. Seeds sowed as soon as the ground warms will bloom later than many of your perennials. And many annuals continue blooming with or without pinching and deadheading. I love petunias in containers because they spread with little effort on my part and need no deadheading, just pinching off of spent buds every now and then to look their best.
It can be a lot of work to deadhead continuously. So it’s probably good to limit the number of annuals that need regular trimming of blooms to force new ones. But some xeric plants such as lavender and salvias will bloom a second time with one trim following the first bloom, so you get a late, bonus wave of color.
Some plants give you plenty of hints (Autumn sedum booms in fall!). But if you have limited space and experience, a xeric landscape designer can help you select the fewest plants possible for continuous bloom.
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.
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.
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.
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.
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.
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.
In 2012, the U.S. Department of Agriculture (USDA) updated its cold hardiness zones. Farmers, suppliers and home gardeners use the zone designations to help standardize how well a plant can survive at average extreme minimum temperatures. In the new iteration, the USDA added two new warm zones to reflect areas in which the average low stays above 50 degrees (if only!). Of course, the zones are restricted to tropical areas of the country, such as Hawaii. Several zone boundaries also shifted to reflect warmer temperatures in several zones from the 30 years of data collection.
Read what you want from the shifts in zones, though the USDA is quick to point out that climate change trends require 50 to 100 years of data collection, and zone changes are not reliable evidence of whether there is global warming.
At any rate, if you haven’t checked your USDA zone in a few years, it’s a good idea to look again and see if it’s shifted. The USDA has given you another reason to check. The scale has fine resolution and GIS technology. This means that between your ZIP code and GIS location, you can have more accurate data to reflect the effects of, say, urban streets and buildings on your townhouse patio. It’s huge for someone like me who lives in a rural area and seldom receives accurate weather data, for instance, unless I collect it in my own back yard. The map recognized my location and pinpointed my zone accordingly as 6B.
Cold hardiness is not the only factor to consider, though, especially for xeriscaping. Altitude affects temperature, but also contributes to drying of plants. And wind, well, don’t get me started. I will say that wind dries a plant out and does plenty of damage to new plantings or houseplants you’re beginning to bring outdoors. You also have to consider soil and microclimates, such as those on the city balcony. On a broader scale, valley or riverbank climates differ from those of mountains or open plains.
Within your xeric garden, you can push a zone slightly by adding plenty of warmth to a plant when you place light-colored gravel under it or plant it near a south-facing wall. Or help out a plant that needs a zone cooler by putting it under the shade of a tree or on the north side of your home. Just be sure to check tags for plant hardiness zone before buying, especially from catalogs, online or in big-box stores.
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.
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.
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.
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.
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.
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.
Any home gardener can create an attractive landscape without filling the entire lawn with lush turf and plants. Having said that, you can achieve a lush lawn with low-water plantings. Add some hardscaping, or built and paved areas, and you’ve got interest and function, a palette for the plants’ colors and textures.
But here’s the rub – and this month’s rant about people who take xeriscaping to the extreme – hardscaping does not mean that you tear out every living blade of grass, and kill (intentionally or unintentionally) every root of every living plant in your yard. In other words, don’t replace the entire landscape with pavement and rocks. In the end, you and your house will be hot, and the only roots that will survive – somehow – will be those of annoying weeds.
You can use rocks quite effectively in a xeric landscape, along with other natural elements. I use the term “natural hardscaping” because if you use found elements from nature, you spend less money and maintain the sort of natural look that many xeric landscapes feature so well. In other words, store-bought pavers have their place, as do concrete and gravel. But I believe they have limited, specific uses, and it’s more fun to add some found elements, such as interesting rocks to your garden.
You don’t have to water rocks, and they can fill or delineate spaces or offset and draw attention to xeric plants. Other great found objects are pieces of wood from old trees (or driftwood), seashells and old metal objects or collectibles that can weather the outdoors. From a practical standpoint, you can use rocks to help well or shore up areas to control drainage, which is a great xeriscaping strategy.
Here are a few tips for using natural hardscaping to complement your xeric garden:
Rounded plants can soften the edges of hardscape materials, such as patio corners or steps. And shorter, round rocks look great behind tall, straight grasses, for instance.
Pea gravel is a great hardscaping element. It’s easier to walk on than larger rock gravel and can serve as mulch for plants that need little water and plenty of heat. You probably want to lay some landscape fabric under the pea gravel and be sure to layer it on thickly to prevent weeds, though.
Use your creativity, adding hardscape elements to make or line paths, for example. You might find rocks or leftover flagstone pieces large enough to bury for stepping stones. Tim placed a large, nearly flat rock under our faucet as a sort of foundation and splash guard.
After making any change that replaces turf or plants with hardscaping, be sure to modify drainage and sprinkler systems to avoid wasting water.
Although wood can work well in the garden, it can sometimes rot or invite pests, such as carpenter ants. So try to use it where it can stay relatively dry or off the ground. Treated wood, such as old railroad ties, fares better.
Rock gardens look best when they appear as rocks might in nature. Burying a large rock a few inches down, and even slightly askew, looks much better than just setting it on top of the ground. Just like with plant selections, mix up rock colors, textures and sizes.
It’s hot here. I thought I would never say that. And sure, it’s not as hot as Phoenix, but even mountain communities in the Southwest can warm up in summer months. When the temperatures hit the 90s, the humidity stays below 25 percent, and the winds never subside, vegetables and ornamental plants get stressed.
Often, our first reaction is to throw more water on a plant. Sometimes, that’s what they need. Wind, sun and heat dry plants more quickly. Native xeric plants are adapted to take some of the parching sun and wind, and sometimes a gardener can overwater a plant. Here are a few tips to keep xeric plants cool, healthy and happy during the heat of summer:
Start with the right plant for the right spot. That means not only a native selection, but choosing sun vs. shade or the right drainage. Most xeric plants can take plenty of sun, but some need partial shade. And most don’t take kindly to wet feet, or roots that fail to dry between watering. Wet feet can happen with overwatering or if you place lavender in poorly draining soil at the bottom of a hill, or hide it under a bush that grows quickly and shades it within a year. You also can plan ahead to take advantage of shade. It’s getting too hot for my lettuce, but we’ll plant some more north of the fence holding the pole beans as soon as they get a little taller.
Follow the sun. When you plant in spring, the sun and shade patterns are different than they will be in mid-July and August. So keep in mind the sun’s direction and any plants or structures that might help shade a plant late in the day, when the sun’s rays are their hottest. Remember that deciduous trees might be nearly bare when you plant, but loaded by mid-June.
When helping a new plant get established, the typical care instructions might not apply. The plant goes into a sort of shock, much like when you recover from illness or injury. All plants need a little more water, as well as extra sun and wind protection until established. We’ve often used portable lawn chairs to provide filtered shade over new plantings in the afternoon. Old sheets or landscape fabric also work.
Use containers. If you have a plant that’s more susceptible to heat stress, place it in a container. You can move it around throughout the summer based on the sun’s path. Of course, if you really love the plant and have lots of time on your hands (and wheels under a larger container), you can move it around during the day, giving it morning sun and afternoon shade.
Water in the morning. It’s tough to find time before work, but watering early in the day loads your plant up, preparing it for the heat. And try to keep soil evenly moist. If you have a slow drip system, the irrigation can run while you get ready for work. Cover the drip hose with a nice, thick layer of mulch and the mulch will slow the water’s evaporation and help keep the ground cool. And as I’ve said before, it’s good to keep an eye on tomatoes and other vegetables and to have someone care for them if you leave town. Once the fruit sets, you can’t drown the tomato to make up for a few days of heat and underwatering. They’ll punish you.
Finally, drink some iced tea, flavored with a small bit of fresh mint. Oh, wait, that’s for me…
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.
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!
Here are some of my favorite low-water annuals, many of which are wildflowers that will reseed:
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.
Here are a few of my favorite low-water perennials:
Echinacea, or coneflower
Sage – any perennial salvia and sage
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.
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.
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.
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!
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.
Of course, if you can go big, do it. There are plenty of professionals, books and sites dedicated to xeric landscaping.