Drought-tolerant annuals and perennials
By Dawn Pettinelli - UConn Home & Garden Education Center
Featured Article - posted Tue., Aug. 7, 2012
The extended dry periods most of us are experiencing this summer have gardeners rethinking the components of our annual and perennial beds. Some plants have faced these dry conditions quite well, while others are listlessly waiting for their meager water ration. Having a well limits our ability to provide plants with much-needed water. Instead, I focus on ways to improve the water retention capabilities of the soil and using greater numbers of drought-tolerant plants in my gardens.
As new beds are dug or older ones refurbished, plenty of organic matter - usually in the form of peat moss, coconut coir, or leaf compost - is incorporated into the soil. Beds are finished with a 1- to 2-inch layer of organic mulch. A thorough soaking every two weeks keeps these heavily-amended areas going. Where I have a lot of self-seeders growing (balsam, ageratum, snow-on-the-mountain, verbena, foxgloves, etc.), I limit the mulch to just barely an inch, with fairly decent results for both moisture conservation as well as germination of next year’s flowers.
I love annuals for their color, season-long bloom, and as cut flowers. Some are doing quite well this year without assistance. Others look pretty pitiful.
One outstanding performer is annual vinca (Catharanthus). “Pacifica Pink,” which I grew from seed, has been blooming since June with large, single, cool pink blossoms. Celosia “New Look Orange” struggled a bit to get established but is now sending forth copious blooms. Self-seeded flowering tobacco, calendulas, sunflowers and Verbena bonariensis have yet to receive supplemental water, but all are blooming their heads off.
All of my direct-seeded zinnia varieties are going strong with a bit of help during their first month. I am disappointed with my tall cutting ageratums like “Red Top,” which seems to keel over every hot day. It does bounce back, so I cut stems early in the morning for arrangements. My most stalwart performers include marigolds, annual baby’s breath, gomphrena, Dahlberg daisy, portulacas, snow-on-the-mountain and salvias.
There are quite a number of drought-tolerant perennials. I see this year I should add some more to my garden. Bee balm, veronica, painted daisies, primroses and stokesias are hit particularly hard by the lack of regular precipitation or irrigation, although the ones in amended areas are faring better. Three cheers for coneflowers, sedums, daylilies, yarrows, penstemons and thread-leaved coreopsis, which are persisting quite nicely. Other perennials carrying their weight include balloon flowers, Korean mums, garden phlox, epimediums, butterfly weed, amsonia, baptisia and echinops.
Though I don’t have them in my garden at the present time, the following perennials are also listed as being drought-tolerant: catananche, red hot poker plant, sea holly and lavender.
Look for herbs also for their ability to withstand dry conditions. Three species of silvery-leaved artemisias have yet to receive additional watering. Also doing well are tansy, Russian sage, thymes, winter savory, southernwood and two species of betony. Many traditional herb plants can be woven into perennial beds for either foliage or flowers.
When creating new plantings, drought-tolerant plants may be well worth considering. In the mean time, let’s hope we get a few more days of rain!
For information on drought-tolerant plants or any other home and garden questions, call, toll-free, 877-486-6271, visit the website www.ladybug.uconn.edu or contact your local Cooperative Extension Center.