Five Perennial Favorites for Fall Planting
By Jan Pipher, Freelance Writer
Though spring planting stirs the heart and soul of the perennial flower gardener, it is fall planting that eventually produces the best plants. The cool, slow growing period of winter encourages root system development, preparing your plants for the summer ahead. By October, the vegetable gardener has most of his fall crops up and growing but the carefree flower gardener is still luxuriating in salvias, coneflower, veronicas, rudbeckias, plumbago, hibiscus, and fall aster, giving little thought to planting, except to wonder what colors of pansies to plant this year. Meanwhile, at the local greenhouses, nurserymen are putting perennial shrubs and flowers on sale to lower their winter inventory and ensure greenhouse space for frost-tender plants. Unbeknownst to the general public, fall is not only an optimum time to start a perennial flower bed, it is usually the best time to find plant bargains as well.
Most zone-8 perennials will benefit from fall planting with just a few exceptions. Frost-tender plants or perennials that are only marginally winter hardy in your area are risky choices for cool season planting. It is possible, with a warm winter or constant attention to mulching and cover through cold spells, to give theses plants a fall start but it involves more work. Often, one faithfully brings a border-line plant all the way through winter's freezes only to be disastrously caught off-guard by a spring cold front! Another caution to keep in mind is the condition of your soil. The winter moisture, so good for most perennials, is the death knell for many of the drought-tolerant species unless your soil is well drained.
There are so many perennials that do well with winter planting that picking five favorites is a little like drawing numbers out of a hat - in which every number is a winner. Sometimes it is nice to think in terms of having some winter bloom in your beds, so there is one qualifier. Flowers and shrubs that are spring blooming are another category because you will receive the benefit of a fuller bloom period after a fall planting. For biennials and especially for slow maturing perennials, Texas' mild winter growing season is the equivalent of half of a year in northern climates, so autumn planting gives these plants a head start on next year's summer color.
One all-around favorite for fall planting is spring blooming Hinckley columbine which is sometimes sold under the name Texas Gold columbine. The nodding yellow flowers of this native of the Big Bend area stand on slender stems above lacy, pale green foliage. Hinckley columbine is a Texas standard for shade plantings but blooms best with cool-season sunlight such as that found under deciduous trees. When planted in a sunny location, Hinckley will flower well but after its March to May bloom period, the beautiful mounding foliage will begin to die back, going into a summer dormancy. Planted in dappled or part shade, the foliage remains an attraction even after the spring bloom season is over. Hinckley should be planted in loose soil, with yearly applications of compost and regular watering. Some years this columbine will pepper your bed with little seedlings. Consider it a gift - thin a few but encourage the rest until fall when they will be big enough to transplant to other beds.
Neither scabiosa, nor its common name, pincushion plant, sound very attractive but this is one of the nicest choices you will find for year round bloom on any nursery shelf. Scabiosa will send up lavender pink or lavender blue flowers through winter, spring, summer and fall. Tiny stamens cover the scallop-edged, umbel shaped flower heads giving rise to the name pincushion. The flowers stand 6 to10 inches above a neat low mound of deeply toothed evergreen foliage. Pincushion plant stays low and small, making it useful in rock gardens or as a nice border plant. It prefers sun or part shade, loose soil, can take periods of drought and plenty of heat.
When planted in the fall, Powis Castle artemesia will give you a touch of silver in your winter beds and astound you with the mound of aromatic gray foliage it produces in the spring. Artemesias are commonly known as wormwood, for their ancient use as a worming medicine. Powis Castle's light foliage, which is an excellent backdrop for garden greens, is representative of the wormwoods. Its large, 3 by 3 foot mounding shape is a hybrid improvement from its family's rougher forms, without forfeiting their toughness. To keep your Powis Castle healthy and within bounds, give it a winter pruning and do not overwater it during the warm months of the year.
One of the classic choices for fall planting is iris. A tall bouquet of sweet-scented iris typifies spring and brings up memories of old gardens, lace curtains and grandmas. Irises do well in full sun to part shade, though they flower early enough to be planted under trees that will not be fully leafed out until after the irises have finished blooming. People are most familiar with bearded iris, which comes in a full range of beautiful colors from white, to yellows, to pinks through rich maroons, to blues and purples including a midnight purple which is nearly black. The name "bearded" comes from the short, fuzzy beard that sprouts from the lower three petals of the flower. Other favorite spring-blooming irises include Dutch iris, another wonderful cut flower; spuria, known for its toughness; Louisiana iris, preferring more water, shade and acid soil; and later-blooming Siberian and Japanese iris, which can be grown as pond plants. All irises except Dutch iris grow from hardy rhizomes, which need to be divided, preferably in the fall, if they begin to crowd each other.
One last favorite for fall planting is the quintessential Texas shrub, Salvia greggii. This small, evergreen bush blooms in red, pink, coral, purple or white all summer long, is drought tolerant, adaptable to anything but wet clay soil (though it will put up a good struggle) attracts butterflies, hummingbirds and other pollinators, and fits into any kind of landscape from English cottage garden to xeric. It is versatile to the point of being over-used but there is nothing else as dependable in a sunny spot, so there is always room for another greggii. What makes this hardy native a favorite for fall planting? Shrubs take a longer growing time to reach maturity, depending on their eventual size. Greggii, being a small shrub (2.5 by 3 feet), can reach almost full growth in a year's time, if it does not have to face its first summer with an immature root system. Try planting an inexpensive 4-inch pot of greggii in the fall. By spring you will have a handsome bush of shiny green leaves and the benefit of an good-sized, blooming shrub by the next summer.