The Waterwise Garden

Coconino County Desert Beardtongue in a waterwise garden


by David Salman, Founder and Chief Horticulturalist at High Country Gardens 

Xeriscaping, also known as waterwise gardening, is a gardening style that has applications to most parts of the country, not just those living in desert regions.

By choosing plants that are well matched to a region's precipitation, along with other factors (such as soil type, soil pH, and climate), a landscape will be colorful, waterwise and low maintenance. Thus, learning about a plant's preferences and then matching these preferences to local conditions will greatly improve its performance. This is what is meant when garden experts recommend using "regionally appropriate" plants.

Plus, we’ll share the best strategies for protecting your waterwise plants.

Matching Plants to Your Region's Precipitation

us rainfall mapus rainfall map

Looking at a rainfall map of the continental United States it is plain to see that rainfall varies dramatically across the country.

For example, the western edge of the Pacific Northwest is famous for its rainy weather; and the map indicates the rainfall here ranges between 50" to 60+" annually. But what this map doesn't tell you is that while this area of the country is soggy from late fall through spring, it's quite dry during the summer and early fall.

As another example, in the high desert of Santa Fe, NM we average 11 inches in a good year. Approximately 60% of it comes as thundershowers in a six-week period during July and August. Winter snows and occasional spring showers deliver the remainder. 

Does the seasonality of a region's rainfall influence plant choices? Much of the time it doesn't, but there are a few exceptions.

For example, regions with Mediterranean climates have wet winters and dry summers, including California and the Pacific Northwest. Plants native to these regions are genetically programmed to go dormant or semi-dormant in the summer, when their habitats are driest. However, in irrigated garden settings, xeric non-native plants that originate in regions having summer rainfall can offer better summer garden performance. Chihuahuan desert natives like Salvia greggi 'Furman's Red'Penstemon psuedospectabilis (Desert Beardtongue) and Agastache cana (Texas Humingbird Mint) are excellent choices because they will grow and bloom when the west coast native flora wants to be dormant.

As a general rule of thumb, it is often easier to take plants native to wetter regions and grow them in drier regions. In the extreme, however, it is not a waterwise strategy to take species that need marshy conditions and move them to the desert.

Agastache Cana will grow and bloom when west coast native flora wants to be dormant.


Matching Plants to A Range of Garden Conditions

Average quality soils that are near to neutral in pH (slightly acidic or slightly alkaline), aren't overly fertile and drain well are suitable for a wide range of plants. Given decent soil to grow in, plants during the spring and summer growing periods can tolerate more rainfall than they might normally receive in their native habitat.

However, this is often not the case in winter, when the plants are dormant. Too much water in freezing winter conditions can be detrimental. When growing a plant in cold weather situations that are much wetter than the plant is accustomed to, it is necessary to provide modified conditions to protect the plants from excessive winter/early spring moisture.

As in all things, moderation is the key. Plants don't mind being in conditions that are somewhat wetter or drier than their native habitats given other conditions like cold hardiness, soil conditions and sunlight requirements are also suitable.

Strategies for Protecting Waterwise Plants

  • Soil Drainage: Providing excellent soil drainage is at the top of the list. This can be accomplished by planting in naturally very sandy soils or by adding a lot of coarse sand (at least half by volume) to the existing soil and mounding it to create a bermed bed.
  • Raised Beds: Making raised beds using sandy soils is another effective method of greatly improving drainage.
  • Planting Site: Different planting sites can have drier or wetter conditions as well. Planting in full sun on the south and west sides of buildings will take advantage of these naturally hotter, drier sites. North and east facing sides of buildings and walls are shadier and will be much damper and less well suited to moisture intolerant species.
  • Cold Frame: If you're really bound and determined to grow xeric plants in an area with wet winters, move a cold frame over small beds for the winter or fabricate a plastic-covered bamboo frame over individual plants. Many rock gardeners in England cover their prize winter moisture sensitive specimens with a pane of glass to keep the soil around the plant's roots dry.

As a general rule of thumb, it is often easier to take plants native to wetter regions and grow them in drier regions. In the extreme, however, it is not a waterwise strategy to take species that need marshy conditions and move them to the desert.

Shop Waterwise Perennials

  1. Lavandula angustifolia Hidcote Superior Photo Courtesy of Walter's Gardens Inc

    Lavandula angustifolia ‚Hidcote Superior‚ (English Lavender) is sweetly fragrant, uniformly compact and blooms with darkly colored lavender-blue flower spikes in late spr...

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    Hidcote Superior English Lavender Hidcote Superior English Lavender Lavandula angustifolia Hidcote Superior
    As low as $13.99 Sale $11.89
    Per Plant - 5" Deep Pot
    Lavandula angustifolia 'Hidcote Superior' (English Lavender) is sweetly fragrant, uniformly compact and blooms with darkly colored lavender-blue flower spikes in late spring.
  2. Richfield Strain Firecracker Beardtongue, Penstemon eatonii Richfield Strain

    24-36„ tall x 15„ wide. The Richfield form of Eaton‚s Beardtongue was selected for its overall vigor and flower production. It blooms in early to mid-spring bloomin...

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    Firecracker Penstemon Richfield Strain Richfield Strain Firecracker Beardtongue Penstemon eatonii Richfield Strain
    As low as $11.99
    Per Plant - 5" Deep Pot
    24-36" tall x 15" wide. The Richfield form of Eaton's Beardtongue was selected for its overall vigor and flower production. It blooms in early to mid-spring blooming with tall spikes of brilliant red flowers. Drought resistant/drought tolerant plant (xeric).
  3. Blut Ice Plant, Delosperma ashtonii Blut

    ‚Blut‚ is one of the very best cold hardy Ice Plants. With its vigorous growth habit, durable evergreen foliage and summer-long display of deep magenta-red flowers, it is...

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    Blut Ice Plant Blut Ice Plant Delosperma ashtonii Blut
    As low as $8.99
    Per Plant - 2.5" Pot
    'Blut' is one of the very best cold hardy Ice Plants. With its vigorous growth habit, durable evergreen foliage and summer-long display of deep magenta-red flowers, it is an invaluable groundcover. Drought resistant/drought tolerant plant (xeric).
  4. Jumbo Waterwise Pre-Planned Garden

    Our Jumbo Waterwise Pre-Planned Garden has been a bestseller for decades! Perfect for hot, dry, sunny gardens, this eye-catching combination of long-blooming perennials will light up...

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    Jumbo Waterwise Pre-Planned Garden Jumbo Waterwise Pre-Planned Garden
    As low as $225.99
    Per Garden of 18
    Our Jumbo Waterwise Pre-Planned Garden has been a bestseller for decades! Perfect for hot, dry, sunny gardens, this eye-catching combination of long-blooming perennials will light up the landscape with bright, clear colors. Grow more flowers and foliage while using less water. Easy-care plants feature inedible foliage to keep rabbits and deer away. Large garden of 27 plants covers 190 sq ft, small garden of 18 plants covers 100 sq ft. This Pre-Planned Garden comes with a garden layout map to make planting easy. (For gardeners in coastal CA, OR, and WA, plant the Jumbo Waterwise Pre-Planned Garden For The West Coast)

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