Submitted by Calvin Finch, Ph.D., Manager, Conservation Division, Water Resources & Conservation Department, SAWS, and Horticulturist
ASSESS YOUR FREEZE DAMAGE
It is time to assess your freeze damage and plan a strategy to repair the damage.
In the vegetable garden most of the newly planted items and even some of the mature plants were destroyed. My garden is in a valley in my backyard where the cold air settles. I lost both the mature broccoli and the young plants. I am going to replant. It is late in the year for a new broccoli crop but it may work if the weather cooperates. Spinach was temporarily flattened but recovered nicely. The potato tops froze off but I believe in most cases they will resprout. Mature carrot foliage was discolored but survived the freezes. Young carrots were fried. Carrots can be reseeded.
Radishes, rutabagas, beets, and chard were frozen back; like the carrots, they can be reseeded. If your onions were lush and growing strongly, the tops are probably mush now. In most cases, they will respout. Texas Cooperative Vegetable Specialist, Dr. Jerry Parsons, believes, however, that the resprouted onions may go to seed rather than bulb appropriately. The advice is to use them up quickly as green onions. English peas were killed; it is too late to reseed them.
So, the scorecard in the vegetable garden is to replant fast-maturing cool weather plants like radishes and the vegetables tolerant of late spring weather like carrots, rutabagas, beets, chard, and broccoli. In late March summer squash and green beans can be planted, followed shortly by melons, tomatoes, peppers, okra, and other hot weather veggies.
In the flower garden most gardeners lost their ornamental kale, stocks, calendula, petunias, and sweet peas. Pansies and cyclamen are probably still blooming. Snapdragons and dianthus lost bloom but they will rebloom and be spectacular this spring. Petunias can be replanted because they bloom into the summer, especially if you use the Laura Bush and Kahuna type (heat tolerant) petunias. New plantings of dianthus can also be used to fill space into the summer, otherwise, wait a few weeks and plant the summer annuals such as begonias and zinnias.
The largest reseeded larkspurs were damaged but most escaped. Bluebonnets in my yard were not phased by the cold but poppies in the low spots seem to be frozen. The other wildflowers will fill in and coreopsis and cosmos can be seeded for later color.
Fruit trees with blooms have lost their flowers but the buds seem intact. Unless your trees were in full bloom it appears that the freeze may just serve as a beneficial thinning. Whatever the situation in your yard, there is nothing that can be done to reroll the dice for fruit trees.
There is some potential for freeze damage on St. Augustine grass. Floratam, our best variety for disease and drought and insect tolerance, is sensitive to cold. I believe, however, that damage will be limited on St. Augustine and that it will quickly fill in when the soil warms. Zoysia, buffalo, and Bermuda grass were dormant and should have escaped any damage.
This may be the first year in the last four or five where we had significant losses of tropical and semi-tropical plants. If your bougainvilleas, tropical hibiscus, plumeria, citrus, and mandevilla were unprotected, expect to replace them.
The winter of 20012002 is also the first time in several years when most root hardy perennials froze back. I see a few lavender lantanas still blooming but no plumbagos, dwarf ruellia, or salvias like past years. For the herbaceous plants like Katy ruellia, it is obvious where the kill line is on the foliage. It is less obvious on other plants. Cut the top off to the point where the stem is green in a cross-section. The freeze-killed parts will have a brown cambium layer (outer ring) or be brown throughout.
One of the easiest ways to deal with freeze killed stems is to just wait four to six weeks. The sprouting will tell you where to prune. I expect plants like Mexican heather, plumbago, lantana, esperanza, rock rose, poinciana, and firebush will be killed to the roots. Shrimp plant, Salvia greggii, Turks cap, and others will show very little stem damage. Plants in the open and in low spots in the landscapes will suffer the most damage.
Irises, paperwhites, Texas mountain laurel, Texas Gold columbines, hyacinths, tulips, redbuds, and quince that were in bloom generally lost the flowers that were open but the closed buds seemed to have escaped damage. This is a year when the slow bloomers survived better than the more precious individuals of the same species.