Drought-Tolerant Perennials

Flowers That Tolerate Full Sun

Image of bluebeard flower.
Bluebeard is a late-bloomer. David Beaulieu

If you wish to grow flowers in an area pounded by full sun all day, consider a landscape plan that focuses on drought-tolerant perennials. The use of such plants will reduce time and money spent on irrigation. Descriptions of the flowers to be planted in one such landscape plan are presented below.

The Plan: an Overview

Here is an overview of the plan that will be referenced below:

  1. Back row: five bluebeard plants (Caryopteris)
  1. Middle row: eight coneflowers (Echinacea), eight Coreopsis, nine stonecrop (Sedum), and one tall ornamental grass, staggered
  2. Front row: five short ornamental grass plants and nine lamb's ears (treated as ground covers), staggered

The flower border of drought-tolerant perennials in this example is approximately 15 feet long by 11 feet wide. Adjust spacing accordingly for your own flower beds, depending on their dimensions. Pictures of individual plants included in the plan are provided atop each page in this article.

Many drought-tolerant perennials are also tolerant of poor-to-average soils. Some even prefer poor soils. Consequently, in addition to being drought tolerant, 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 flowers in this plan prefer soils that are well-drained, and nothing facilitates drainage like plain old, infertile sand.

The Plants: Descriptions

"Longwood Blue" bluebeard (Caryopteris x clandonensis 'Longwood Blue') is a drought-tolerant perennial that reaches a height of 3’ x 4’ and a spread of 2’ x 4’.

Bluebeard is actually classified as a deciduous shrub, although many gardeners use it as they would a perennial. Bluebeard 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 late winter or early spring, and await its rebirth later in spring. Also called “blue mist” or “blue spirea,” its prominent features are its airy 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 layered flower bed. Culver's root is another tall perennial that is tough enough to grow in dry soil; however, it is not as safe a choice as bluebeard, since it is potentially aggressive (although it is unlikely to spread much under truly dry conditions). On Page 2 we'll discuss selections for the middle and front rows of our plan composed of drought-tolerant perennials....

Having considered the back row on Page 1, now let's turn our attention to the middle and front rows in this garden of drought-tolerant perennial flowers. 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 perennial flowers 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 (there are other types as well, such as orange coneflowers). 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. In this plan, we are cutting off the flower spikes, so as to keep the height of our lamb's ears down to a minimum. Indeed, the plant is grown primarily for its silvery foliage -- which has a velvety texture -- not its flowers. 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 (not counting its flower spike), perennial Lamb's ears can be an excellent choice for the front row of a layered flower bed (with taller plants residing in the back row and medium-sized plants in the middle row).

On the other hand, if you enjoy the flower spikes of lamb's ears and wish to retain them, treat this perennial as a back-row plant, rather than as a ground cover for the front row.

If you wish to grow a spiky drought-tolerant perennial that produces a more attractive flower spike, try red hot poker plant. If you need a really short plant, consider bitterroot (Lewisia).

Complete the plant selection for your garden of drought-tolerant perennials by choosing one tall ornamental grass variety and another that stays short. Options for drought-tolerant ornamental grasses will be discussed on Page 3. Or if you'd prefer, you can return to the Drought-Resistant Plants index and learn about other types of plants (trees, shrubs, ground covers) that hold up well under dry conditions....

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.

Drought-tolerant ornamental grasses similar to maidengrass are:

 

Blue fescue (Festuca glauca ‘Elijah Blue’) will provide your landscape plan with a reasonably drought-tolerant ornamental grass that is shorter (usually a bit under 1’ x 1’). While it tolerates dry conditions fairly well once established, it is not, however, as drought-tolerant as is maidengrass. It is 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.

What about medium-sized plants?

Purple fountain grass is as pretty as its name would indicate, and it's drought-tolerant to boot. Although it is not in the landscape plan provided here, mention should also be made of another 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 plant 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.

Although it is technically in the lily family, liriope is usually treated as if it were an ornamental grass. Take one look at its blade-shaped leaves and you'll understand why. This is another plant that holds up pretty well to dry conditions. As such, I include it here with the drought-tolerant ornamental grasses.

To view the arrangement of some of the plants mentioned in this article in a drawing, an accompanying drought-tolerant landscape plan has been provided.

Return to Drought-Resistant Plants index.