Primetime Newspapers
By Calvin Finch, PhD, SAWS Conservation Director, and Horticulturist
Week of April 12, 2004

EARLY SUMMER ANNUALS

The spring has been great for blooms. Remember that some of the plants blooming right now such as bluebonnets and larkspur are reseeding annuals. They are beautiful when they are blooming but not so attractive when the seed is maturing. If they are to return next year, however, they must be allowed to mature and drop their seed. The “ugly period” must be tolerated. Daffodils, paperwhites, and irises have a similar situation. They do not mature seed but the foliage is manufacturing starch to store in the bulbs, rhizomes, and other storage organs so that plant can survive the rest of the year and bloom next spring. For this process to work, the foliage must be allowed to stay in place until it browns naturally. Do not mow the foliage too early.

The Semperfloren begonias are good choices for the summer flowerbed. Selections in the “Cocktail” series will bloom all summer and late into the fall in mottled shade and even in the sun, if you get them in the ground in April and early May. Begonias are partial to cool weather so they do most of their growth in the early summer. Through mid summer, if they are well established, they hang on. In the autumn, they perk up again. Semperfloren begonias, despite their lush look, operate a lot like succulents. They can quit growing and tolerate tough conditions such as a full sun flowerbed in a San Antonio summer.

Zinnias are good annual flowers for the San Antonio area. They are easy to grow from seed and make a spectacular show with red, pink, white, lavender, yellow bicolor and even green blooms. There is considerable choice in plant size and flower conformation. Zinnias range in size from about 8-inches tall to 3-feet tall. The most common transplant is Dreamland with flat 4-inch blooms with rounded sides on 18-inch plants. Dreamland is a hybrid that resists powdery mildew better than most other varieties. Zinnias will reseed and bloom several times over the summer. Butterflies like all zinnias, but in the case of the Dreamland, they like the reseeded plants better than the original transplants. The mixed bag of reseeded zinnias representing the Dreamland parentage seems to provide more nectar than the nursery variety. For long bloom it is important to deadhead Dreamland and other large-flowered zinnias.

            Zinnia linearis is a hardy version of zinnia. The small white and gold daisy-like blooms cover the 18-inch rounded plant. The selection ‘Profusion’ is another bush form with small blooms, in this case, yellow or pink. Both of these bush zinnias will survive the summer after an early season show. There will be a few blooms in the summer and then an autumn peak bloom.

Celosia comes in two main forms, the plume type and the cockscomb version. The new selections of celosia can be relatively small, 10 or 12 inches and uniform in growth. Modern celosia comes in all the same colors as zinnias. My favorite celosia are the old-fashioned selections. The plants are often very aggressive and prone to reseeding but the colors can be more intense. The old-fashioned red cockscomb is especially rough and ready. The blooms are susceptible to rain damage. Find celosia seed and transplants at your favorite nursery or go on the Internet to one of the old-fashioned seed nurseries. Butterflies and hummingbirds like celosia.

Pentas are a perennial in some situations but, as a plant with tropical origins, they usually freeze back. Pentas are probably the best flower for butterflies of all our options. The red, white, pink, and violet blooms also attract hummingbirds. Some selections of pentas can reach 30 inches tall but they do well in containers or the flowerbed. Pentas even have some shade tolerance. Use them in full sun or part sun. Watch for hornworms. One caterpillar can strip a penta overnight.

Wait on vincas until at least June. They love hot dry weather but melt down if the humidity is high and/or they are watered overhead.