On the Dry Side

With greater force than ever before, water conservation is back on the minds of governments, landscape professionals and property owners these days – and for good reason: The combination of growing demand and recurring periods of drought has sensitized people in many parts of the country to the fact that water isn’t an infinite resource.

Even this new magazine is part of the dialogue: In the September/October 2006 issue of LandShapes, James Minnich defined the need for landshapers to become more aware of water conservation techniques in the form of efficient irrigation systems (click here). Adding to that discussion, let’s turn to the flip side of the water-conservation issue and explore the ways a drought-tolerant plant palette can aid the cause.

Using these plants to create xeriscapes, as they’re commonly called, is the key to water-wise, water-efficient landscaping. Unfortunately, there are lots of misconceptions about this approach to garden development – not the least of which are tendencies among well-intentioned clients to call them “xeroscapes” and a more general supposition that they’re mostly about the use of rocks and gravel.

While it’s true that some xeriscape practitioners rely heavily on rocks and gravel in some cases, this form of environmentally friendly landscaping encompasses a much broader spectrum of plant types and planting styles than most clients recognize. Xeriscaping is primarily defined by its creative use of water-efficient plants and their pairing with complementary hardscape elements. They also differ from their traditional counterparts in that they emphasize plants’ visual importance in all four seasons.

A CALL TO ACTION

The term xeriscape was introduced in 1981 by the Associated Landscape Contractors of Colorado and was first used in Denver in 1982. It makes sense that the approach would emerge in the intermountain west, where valleys feature wet winters followed by exceedingly dry summers. Plants in these areas must adapt to alkaline soils, desiccating winds, extreme temperature fluctuations, limited seasonal precipitation and searing sunlight.

With a business based in Salt Lake City, I am familiar with these climatic conditions, and I’ve also witnessed the ebb and flow of affection for xeriscaping through the years: It would catch on for a while, then interest would fade – usually up in response to persistent drought conditions or realistic concerns about water supplies in our desert region and down again when the rains came.

About ten years ago, I broke away from these roller-coaster cycles and began talking seriously and consistently with all of my clients about the need to conserve water in their landscapes no matter what the immediate weather situation was or the state of the water supply.

INCREDIBLE COLORS: Most clients are surprised by the depth and range of colors available to them in xeriscape gardens – not to mention the persistence of the blossoms and the subtlety of their appearance.

Right about then, we experienced four consecutive drought years, and public awareness of water conservation hit new heights. Local media focused on the need for everyone to conserve water through responsible landscape and irrigation practices, and appreciation of the fact that we would always be subject to these cycles elevated xeriscaping in the public’s eyes at every demographic level.

Within this revival (and its apparent persistence) are several consumer rationales for thinking about drought tolerance, with most of the concern focusing on the vast quantities of water consumed by traditional landscapes – a view bolstered by experts’ estimates that average homeowners and businesses devote 65 percent of total water use to landscape maintenance. (This is a powerful argument in Utah, the second driest state in the union and a place that has one of the lowest water rates in the country).

Acting on their own, homeowners all too often combat excessive water consumption by reducing existing lawn space or turning it into hardscape. Some will upgrade their irrigation systems with more efficient sprinkler heads on lawns and drip systems for planting beds, while others will reduce their existing turf area and replace it with water-efficient plantings. Basically, they’re all looking for a lower-maintenance landscape that will fit into their busy lifestyles, budgets and, for some sense of social responsibility.

CHANGING DIRECTIONS

In my part of Utah in particular, traditional Kentucky Bluegrass lawns have long predominated. This water-thirsty grass followed our forefathers across the continent and is one of the highest-maintenance turfs you’ll ever encounter. Moreover, traditional lawn-dominated landscapes frequently lack the variety xeriscapes display.

What I’ve observed is that homeowners saddled with these traditional lawns are increasingly interested in lower-maintenance xeriscape plantings. After all, if they neglect watering, edging and mowing a Kentucky Bluegrass lawn for a week in summer, the effects are immediately apparent. But if they leave a well-designed xeriscape alone for a month or longer, they’ll see little (if any) visual degradation.

I’m also finding that these homeowners are pleased to learn that a widening variety of drought-tolerant plants is available, including many trees, shrubs, perennials, ornamental grasses and groundcovers – all of them indigenous to our area or adaptive to dry climates. Even some roses, spring bulbs and irises do very well in this type of environment. The common denominator with all of these plants is their ability to thrive in the face of high temperatures, low relative humidity and alkaline soils – and the fact that, once established, all they need is infrequent deep watering.

NARROW PALETTES: The richest potential of xeriscaping may be seen in its wonderful greens – a range of shades that lend texture, contrast and variety even when the deployed array of colors is held within slim tonal boundaries.

As consumer demand and media attention have risen for xeriscaping, plant availability and selection have expanded as well. In the early years, I often experienced difficulty in filling plant orders, as most nurseries carried a limited inventory (if any at all) of drought-tolerant plants. As is usually the case, when the public began asking for them, growers and nurseries responded favorably.

It’s important to note, however, that there is always a lag time between initial consumer requests for specific plants and their arrival at the nursery: Obviously, demand needs to increase sufficiently before it’s economically sound for a grower to supply a given plant. The good news locally is that xeriscape plants are “hot” these days, meaning they’re widely available not only through nurseries but also on the Internet, through catalogs, common retail outlets and direct from growers.

Even with these newly available plants, however, it has proved difficult to dispel the most common of all misconceptions about xeriscaping – that is, “xeriscape” means cactus and rocks. Nothing, of course, could be farther from the truth.

DRY CHOICES

Xeriscapes are often quite green, colorful and welcoming and have plenty of the positive attributes that appeal to a broad range of observers: They can be just as green, lush and attractive as traditional landscapes, even more so because of the tremendous variety of available plants.

Trees displaying exfoliating bark, colorful spring flowers, brilliant fall colors and persistent winter fruit, for example, serve to offer seasonal interest. I also like to use fragrant perennials exuding rich fragrances of root beer, chocolate and lavender close to paths and terraces. And if that’s not enough, ornamental grasses are low-maintenance, impart movement and drama to the landscape and show off their inflorescence when back-lit.

But it’s with the maintenance benefits of these water-conserving, heat-tolerant, colorful xeriscape plants compared to traditional landscape components that the advantages become most obvious. In fact, designing with plants adapted to our harsh climate produces landscapes that essentially maintain themselves. Simply replacing water-thirsty turf grasses with drought-tolerant groundcovers including Thymes, certain varieties of tall fescue turf grasses, Buffalo grass and Blue Grama grass is a great start.

ROCKY ROAD: While some xeriscapes are dominated by rocks and gravel, my goal is to integrate these materials into reasonably naturalistic compositions that show all materials off harmoniously and in the best possible light.

Although xeriscapes initially cost more to implement than traditional landscapes, property owners are often convinced to convert by the water-bill factor. Studies have repeatedly shown that well-designed xeriscapes, when watered responsibly or combined with water-conserving irrigation systems, offer real and considerable savings. Where established xeriscapes get by on infrequent, deep watering, traditional landscapes typically require daily watering or, at the very least, a good drenching several times a week.

To make xeriscaping a movement rather than a fad, I see the need for education about all these issues among professional landshapers, suppliers and property owners. A key need is for a greater flow of information about water-conserving irrigation technologies intended for drought-tolerant plantings. Too few of us are familiar enough to be comfortable with drip systems – the result being that, all too often, the first sign of a problem is a dead or dying plant.

I’ve pushed myself pretty far along this particular learning curve, and now most of my xeriscapes are drip-irrigated with the exception of functional lawn areas or Thyme lawns that call for spray heads. We install laterals for these systems early in a project, stubbing them up for in-line or drip emitters. Once the plants are in place, we adjust these elements to specific plant locations and conduct thorough tests.

GOOD TO GO

When I first began exploring the possibilities of xeriscaping, I often had the feeling that I had no choice but to blaze trails, improvise and just make things work.

Happily, I’m not so lonely anymore: Drip-irrigation technology, for example, has come a very long way since its early years to a point where it’s now used on a variety of commercial and residential projects and its components are holding up and building a base of satisfied clients. The early filtration problems and clogged emitters are largely a thing of the past, and we’ve also learned a lot about where best to place in-line or drip emitters for greatest effectiveness with various plant species.

GOSSAMER STRANDS: Some of the most compelling xeriscapes have a wild edge to them – assemblages of plants that overrun a space and any hardscape details with a most appealing impression of nature’s bounty.

The use of these systems has had wonderful consequences for plants, allowing a greater variety of them to get established to a point where only occasional deep watering is necessary. That’s important: Even though xeriscape plants are ultimately tougher than their traditional counterparts, they still require establishment periods of two to six months during which they need more water than they will later on.

We’ve also learned a lot through the years about soil structure as the foundation for vigorous plant growth. Many xeriscape plants benefit early on from having organic matter tilled into existing soil. It’s also my observation that drought-tolerant plants are like traditional container-grown plants in that both need to be “weaned” from their nursery-soil mix. In the case of xeriscape plants, they must adapt to typical alkaline or clay soils in rapid order.

During their establishment period, these plants require a consistent water supply, and organic matter helps by promoting essential water and nutrient movement. I’ve seen that new plants in well-prepared soil grow twice as fast as those in unprepared soil, despite the fact that I’ve heard some experts advise against using any soil amendment for water-wise plants. Experience tells me the opposite – that establishing plants do best when I till some organic matter into the existing soil.

Above all, many xeriscape plants require well-drained soil and regular watering during their first two to six months in the ground. If the native soil is lean or lacking in organic matter, plants will have difficulty because that water will move away too quickly and the plants will dry out too much between waterings. With clay soils, by contrast, too much water remains around the plant’s roots, resulting in an early demise. I solve this problem by tilling a soil mix such as Utelite Root Zone into the clay to lighten up its structure.

INTERSECTIONS: Xeriscapes are ideal when it comes to spaces in which they come to terms with hardscape details and outdoor furnishings – a welcome, welcoming mix of colors and textures that invites people right into the setting.

By no means am I recommending wholesale soil replacement here: On most of my projects, I specify thorough tilling of four to eight inches of soil amendment into the existing soil using a technique taught to me by Rob Schocker of Schocker Sprinkler and Landscape in Salt Lake City. He and his crew only till in three inches of amendment at a time, allowing for a thorough mixing of old and new.

The first time I saw them use this approach was on a site where we removed eight to ten inches of existing clay from the entire surface. After we tilled in generous quantities of soil amendment, the plants really took off and the owner was amazed by the quality of the soil and how easy it was to work.

CLEAR BENEFITS

No matter what your reasons for considering a water-conserving landscape, it seems inevitable that xeriscaping will become a more valuable approach as time passes and water resources become more valuable. Best of all, my clients are getting up to speed with this garden style and readily see the value when it comes time to rethink their exterior environments.

And what’s not to like? Xeriscaping offers valuable landscape-design benefits in the form of sustainability, bio-diversity, significant water savings, seasonal interest, wildlife-friendly settings and therapeutic effects. It’s a movement, I think, whose time has come.

Rick Laughlin is a professional landscape designer based in Salt Lake City. He switched to a career in landscape design following a long corporate career in computers and holds a Bachelor of Science in Forestry Resource Management and Wildlife Management to go along with a strong background in studying the natural world, extensive horticultural experience and practical work experience in all facets of the Green Industry. He emphasizes that his pursuit of continuing education on a yearly basis, both here and abroad, is what keeps him current and at the top of his field. Laughlin specializes in water-wise landscaping and is a member of the Association of Professional Landscape Designers. He can be reached at [email protected].