It's pretty amazing when you hand a few brushes and a collection of paints to a skilled artist. You stand there and watch the masterpiece unfold, stroke by stroke.And so it is with perennial gardens. In the hands (and mind) of a truly professional plant person, a perennial garden becomes a living, breathing work of horticultural art. Or, it can be smudges of finger paints. Compared with any other part of landscaping, perennial gardens require a better knowledge of design and a higher level of familiarity with plants. Let's make a list of the facts and the basics.Perennials are not less work than annuals. Sure, they'll survive for years, while annual plantings must be redone two or three times every year. But you still have to dig and divide your perennials to keep them from becoming overcrowded. You still have to work the soil, and much of that work must be done by hand, because not all perennials can be reset in the same season.Most types of perennials flower for two or three weeks out of the year. Annuals may remain in full bloom for four to six months.Perennial gardens work best when they're made up of collections of 15 or 25 types of perennial plants. That allows for the cycles of blooms, so that you'll always have several types in peak flower.By comparison, perennial gardens are least effective when they consist of large masses of single types of plants. A long row of iris or day lilies can be spectacular when they're in full flower, but they may look almost pitiful just a few weeks later.Perennials are most effective when they're tucked into plantings that include shrubs for continuity, annuals for ongoing color and garden art for the fun it brings to the landscape. Sure, you can have a large bed that is made up primarily of perennials, but the shrubs give it structure during the winter "down" times, and the annuals make sure that it is always attractive.Most perennials perform best in full or nearly full sun. And, because they do go dormant each winter, they generally look best when they are planted out away from the house. Dark-colored backdrops, for example, from tall screening evergreens or brick or stone walls make the best staging.Perennials, as a rule, grow best when they are planted in well-draining, highly organic garden soil. Elevate the bed by 4 to 6 inches by incorporating 1 inch each of sphagnum peat moss, rotted manure, finely ground pine bark mulch and compost, along with 1 inch of expanded shale if you're amending a clay soil. Rototill to a depth of 12 to 14 inches.Know each plant's blooming season, and arrange your varieties so there will be several types in flower at the same time. As further protection against "holes" without color, repeat your plant types in two or three places within the bed, so they will all be in bloom at the same time. Along that same line, plant in fairly natural clusters, clumps and small drifts.You may want to have a color scheme for your garden. However, be warned that this is where things get really complicated. Perennials don't always flower on the same schedules year after year, so you can be left with a bed of primarily blues, purples and pinks -- and with one bold yellow flower sticking out in the midst. That's all the more reason not to plant perennials in big masses where one color can dominate.Know your plants' mature heights and widths. You don't want the tall types to be in the foreground, nor the trailers to be in the rear, and no plant does well when it's crowded. Part of all that comes with experience, but you can also learn a lot by doing your homework before you start planting.You can also reduce crowding if you dig and divide your plants regularly. That's usually every two to four years. Spring and summer bloomers are dug in the fall, and fall-flowering perennials are moved in early spring. Save only enough plants to fill in the voids; give the extras to others, replant them elsewhere, or send them to the compost.There is never a wrong time to begin a perennial garden. However, spring may be the best time of all. Nurseries will be filling up their inventories of quart- and gallon-size plants over the next couple of months. Do your designing and bed preparation. Then and only then, look for healthy, vigorous plants.Neil Sperry publishes "Gardens" magazine and hosts "Texas Gardening" from 8 to 11 a.m. Sundays on WBAP AM/FM. Reach him during those hours at 800-288-9227 or 214-787-1820.
Best perennials for North Texas
(This list is far from complete, but it will give you a good starting point. It's offered in rough sequence of bloom.)
Spring: daffodils, jonquils and narcissus, candytuft, species tulips, autumn sage, thrift, oxalis, grape hyacinth, summer snowflake, ajuga, yarrow, Homestead Purple verbena, iris, Byzantine glads, Texas Gold columbine, hardy amaryllis, roses, red yucca, crinums, coneflowers.
Summer: day lilies, Shasta daisies, gloriosa daisies, cannas, hardy hibiscus (mallows), summer phlox, Turk's cap.
Fall: oxblood lilies, spider lilies, fall crocus, fall aster, Gregg's ageratum, Mexican bush sage, Mexican mint marigold, mums.