Due to the fact that the weather has been abnormally warm for this time of the year, it could make it hard to go by the planting calendar. University of Missouri Extension Horticulture Specialist Marlin Bates says we typically wait until the threat of frost has passed before we start our gardens. Bates says if you do plant early, it’s a good idea to have a plan in place to protect the plants just in case a frost does occur.

Click here to listen to KMZU’s Mandy Young talk with Horticulture Specialist Marlin Bates:
Marlin Bates

This may be the year to throw the planting calendar out the door
By Marlin Bates, Horticulture Specialist

(BLUE SPRINGS, MO) Many gardeners often push the envelope to get frost-tender plants in the ground in hopes of earlier harvests. We typically expect the last killing frost in our area to occur in late April or early May. Gardeners seeking that early establishment and subsequent early harvest are known to plant frost-tender plants as early as the beginning of April. Often, their gamble that killing frosts are in the past doesn’t pay off. This year may be different.
Certainly the allure of getting the gardening season off to an early start is in the air. With the current warm spell extending well beyond what many gardeners initially anticipated, it is looking more like it just may stay warm. Conversations three weeks ago seemed to revolve around how we should expect normal, cooler weather to set back all of the plants that were coming to life due to the warmer weather. Now, those conversations seemingly have turned toward the likelihood that the warm weather is here to stay.
Of course nobody can predict when the last frost will be with great certainty. This means that those gardeners, who are anxious to get warm-season vegetables in the ground early, may want to do so with caution. There is a good guideline to follow to make sure that early-planted, frost-tender vegetables don’t succumb to injury from frost.
After transplants have been placed in the garden or after seeds have sprouted, it’s a good idea to have a form of plant protection ready for deployment. By creating an insulated barrier between frost-tender plants and the atmosphere on nights when temperatures are expected to be below the plant’s threshold, gardeners can keep the microclimate around the plant warmer than ambient temperatures. The most common form of this type of barrier is floating row cover, though light blankets can be used as well. Thin, breathable fabrics can provide a few degrees of protection, but do little to protect plants when temperatures are in the low 20s or below. Heavier fabrics can provide more protection, but may also damage plants with their weight. If you use a heavier fabric, consider installing a scaffold to keep the cloth from weighing down plants. In either case, it is a good idea to have the cover close to the top of the plant as opposed to suspended well above the canopy.
For gardeners who are less certain of their ability to predict when the frost-free season begins, or who may not want to deploy plant protection on low temperature nights, there is another option. There are plenty of cool-season vegetables that can still be planted and harvested in time to plant warm-season vegetables on their recommended dates. Short-season vegetables like radish, baby bok choy, lettuce, swiss chard, and others can be harvested within 45 days of sowing. This will free up the necessary garden space to allow for warm-season vegetable planting, all while satisfying the temptation of getting into the garden during this warm spring.
For those gardeners who want to plant by the book, University of Missouri Extension offers a free guide on vegetable planting dates. This guide provides information on how much to grow, days to harvest, and recommended varieties, among other things. The Vegetable Planting Calendar is available at  http://extension.missouri.edu/p/G6201.
For more information, contact specialist’s name, number, e-mail or visit your local Extension Center or extension.missouri.edu.