Drought Tolerant Plants

Drought-Tolerant Landscape Plants
Perennial Flowers, Drought-Tolerant Plants
By David Beaulieu, About.com

If you wish to grow perennial flowers in an area pounded by the sun all day, consider a landscape plan that focuses on drought-tolerant plants. The use of drought-tolerant plants will reduce time and money spent on irrigation. Descriptions of the perennial flowers to be planted in one such landscape plan are presented below.
To view the arrangement of these perennial flowers in a drawing, an accompanying drought-tolerant landscape plan has been provided. This landscape plan indicates which perennial flowers should be placed in the back row, which plants belong in the middle row and which plants will go in the front row. The perennial bed in this example is approximately 15’ long by 11’ wide. Adjust spacing accordingly for your own perennial beds, depending on their dimensions. Pictures of individual perennials included in the landscape plan are provided in the photo gallery atop each page in this article.
Many drought-tolerant plants are also tolerant of poor-to-average soils. Some even prefer poor soils. Consequently, in addition to drought tolerance, the following perennials were also selected with an eye to soil-quality requirements. Namely, none of them are plants on which you need to waste valuable humus. Save your hard-earned humus for plants that require a rich, fertile soil. The perennials in this landscape plan prefer soils that are well-drained, and nothing facilitates drainage like plain old, infertile sand.
"Longwood Blue" bluebeard (Caryopteris x clandonensis 'Longwood Blue') is a drought-tolerant deciduous shrub that reaches a height of 3’ x 4’ and a spread of 2’ x 4’. It can be grown in zones 5-9, but in zone 5 and 6 it should be treated as an herbaceous perennial; cut above-ground growth back in winter, and await its rebirth in spring! Also called “blue mist” or “blue spirea,” its prominent features are its dense clusters of fragrant blue flowers and its silvery-gray foliage. Flowering begins in late summer and continues into autumn. Bluebeard’s blooms attract butterflies.
Because of its healthy height, bluebeard is a good choice for the back row of a bed of perennial flowers.

Now let's turn our attention to the middle and front rows in this garden of drought-tolerant perennials. While the tough-looking "Autumn Joy" sedum is a favorite perennial for sun-battered gardens, don't think you have to give up the more delicate-looking "Moonbeam" coreopsis.
A popular choice for drought-tolerant perennials is “Autumn Joy” sedum (Sedum "Autumn Joy" or Hylotelephium "Autumn Joy"), also known as "stonecrop." This sedum is a perennial favorite in rock gardens, as the "stone" in its alias would suggest. Autumn Joy sedum's foliage consists of succulent leaves in whorls. The leaves are sometimes variegated and can range in color from bluish-green or greenish-yellow to reddish-pink or almost off-white.
But sedum is not just a foliage plant. It produces an unusual flower well worth growing in its own right. Sedum's flowers can be yellow, orange, red, or pink. Flowers usually bloom in clusters above the foliage. Grown in zones 3-9, this perennial’s dimensions are roughly 2’ x 2’. Autumn Joy sedum is a butterfly magnet.
Moonbeam coreopsis (Coreopsis verticillata ‘Moonbeam’) is one of the threadleaf coreopsis varieties. Reaching 2’ x 2’ and bearing clusters of light yellow, daisy-like blooms, these perennials are grown in zones 3-9. Can be invasive. Like the next entry, purple coneflower, this bushy plant is valued for its long blooming period; but coreopsis is the more consistent bloomer of the two.
Purple coneflower (Echinacea purpurea) can be grown in zones 3-8 and is a native of the Eastern U.S. Reaching 2’-3’ in height and 2’ in width, its daisy-like flower color ranges from pink to purple. Divide every few years to increase your stock and keep plants healthy. The seeds of its “cone” attract goldfinches. Valued for its long blooming period (throughout the summer and into fall). It is from this plant that “echinacea supplement” is derived, an herbal remedy for cold and flu sufferers.
Lamb's ears (Stachys byzantina) provides wonderful texture in rock gardens and spreads readily. Indeed, it is invasive; but just this quality can make it an effective groundcover, if you don’t mind it taking over. Although not grown for its bloom, lamb's ears does produce light purple flowers on tall spikes. It is grown for its silvery foliage, which has a velvety texture. The shape and texture of its leaf readily explains how lamb's ears got its name. Lamb’s ears is deer-resistant; apparently it is this same texture that makes lamb's ears unpalatable to deer.
Like bluebeard, coneflower, coreopsis and stonecrop, this plant is an herbaceous perennial. Because it usually reaches only about 1’ in height (with a similar spread), perennial Lamb's ears is an excellent choice for the front row in a perennial bed consisting of a multi-tiered bed (with taller plants residing in the back row).
Complete the plant selection for your garden of drought-tolerant perennials by choosing one tall ornamental grass variety and another that stays short.

Maidengrass (Miscanthus sinensis ‘Gracillimus’) is a fine choice in zones 5-9 for a tall drought-tolerant ornamental grass, as it reaches as much as 7’ in height, with a spread a bit less than that. Place it towards the rear of the middle row, and center it, for this will be our focal point. Maidengrass bears coppery tassels as a seed-head in early fall, eventually growing lighter in color and adorning the plant as a “plume.” Don’t cut the clump’s stems back until after the bleakness of winter passes, since the graceful stems and puffy plumes of this plant will provide some visual interest on an otherwise barren December-February landscape.
Blue fescue (Festuca glauca ‘Elijah Blue’) will provide your drought-tolerant landscape plan with a shorter ornamental grass (usually a bit under 1’ x 1’). Grown in zones 4-8. The popularity of this clumping grass lies in the blue color of its foliage, which will beautifully complement the silvery foliage of our lamb’s ears. Meanwhile, its spiky appearance will stand out in contrast to the smoothness of the lamb’s ears. The plant rather resembles a pincushion bristling with blue pins. As with maidengrass, cut back foliage in early spring. Divide every few years to rejuvenate.
Although it is not in the landscape plan provided here, mention should also be made of a drought-tolerant ornamental grass of intermediate height to complement the perennial flowers discussed on Page 2. Northern sea oats (Chasmanthium latifolium) is an ornamental grass that grows 24"-36" high in loose clumps of green foliage. Its name derives from its seed pods, which look like oats. This deer-resistant ornamental grass is cold hardy to zone 5. Should you wish to mass together several clumps of an ornamental grass variety in the middle row, northern sea oats would be an excellent choice.
To view the arrangement of these plants in a drawing, an accompanying drought-tolerant landscape plan has been provided.