Jennifer Schultz Nelson
Extension Educator, Horticulture
Just because it's fall doesn't mean that the vegetable gardening season is over yet. Many spring vegetables such as turnip greens, lettuce, and broccoli can be sown in late summer and harvested in the fall. One major advantage of planting these in late summer is that the soil is thoroughly warm. Unlike spring, when cold clammy soil and air can mean certain death for young seedlings, the warm air and soil of late summer creates a nearly ideal situation for seed germination.
Turnip greens are typically associated with dishes originating in the southern United States. But historically turnips have been cultivated a lot longer than the U.S. has existed. Turnips are believed to be native to central and southern Europe, and were probably domesticated by people living in and around the Mediterranean region.
Their cultivation dates back over 4000 years, and were consumed in both Ancient Greece and the Roman Empire.
While many people grow turnips solely for their green tops, many also consume the large storage root either raw or cooked. Before white potatoes were introduced to Europe in the 15th century, turnips were the staple food of choice. Varieties with large roots were typically used to feed livestock, while the more tender, smaller, sweeter varieties were preferred for human consumption.
Turnips are a great example of a biennial plant that needs vernalization in order to flower and set seed. A biennial plant is one whose life cycle occurs over two years–the first year only leaves, or vegetative tissue, is produced, and the following year flowers, or reproductive tissue develops. The term vernalization means subjecting plants to low temperatures that mimic the winter months, triggering the development of flowers. The term originates from the Latin word "vernus" meaning "of the spring". Essentially, the word describes what the plant requires–winter followed by spring.
Without the low temperatures of the winter months, a turnip plant continues to produce leaves. Collecting seed is a long drawn out process when depending on the weather to trigger events. Plant breeders have devised ways to trick the plants into flowering, accelerating the process of developing new varieties.
Depending on the plant, exposing it to low temperatures for a specific length of time will initiate flowering. This could be as small scale as a flat of seedlings placed in a cold chamber, or even as large as an entire greenhouse range of full-grown plants chilled to the right temperature.
Accelerating the flowering process by artificially vernalizing plants helps breeders produce multiple generations of plants in a given year, ultimately translating to new varieties being introduced at a faster rate, something most every gardener finds appealing.
The "typical" turnip has a white fleshed root, sometimes with a purple color on outer skin exposed to sunlight. New varieties have revealed a host of genetic diversity, producing cultivars with traits like yellow flesh, red skin, and a wide range of size, shape, and sugar content. Some cultivars, like 'Seven Top' are bred for better greens, rather than the fleshy root. In cultivars bred for greens, the fleshy root may be very small or nonexistent.
Turnips will tolerate a fair amount of frost, and may become sweeter after a light frost, but if left in the ground after the soil freezes, the quality of the root declines. A heavy layer of mulch will prevent the soil from freezing and allow turnips to remain in the ground until needed. Roots will tolerate storage in other cold locations, such as refrigerators or root cellars. The greens will withstand a great deal of frost, but lose quality quickly when freezing temperatures set in.
Generally greens are best picked within hours of using them. Traditional Southern U.S. dishes typically cook greens in combination with pork. Everyone seems to have their own favorite or even secret recipe.
If you are interested in cooking up your own batch of fresher-than-fresh greens, your golden opportunity is this week. The gardeners from Operation Green Thumb, a community gardening group here in Decatur will be harvesting greens on Tuesday October 10th, and Wednesday October 11th. The gardeners grew these greens for families in Decatur that may not be able to put food on their tables–especially fresh produce.
They will distribute the greens immediately after harvest, at approximately 8 a.m. in the parking lot behind the UAW Local #751, 2365 East Geddes Ave in Decatur. There is no charge for the greens, but remember there are a lot of hungry people in the Decatur area that can't afford to feed their families. The demand is so great that many local food banks are forced to turn residents away because they have no food to give. Donations to Operation Green Thumb in exchange for greens will be encouraged and gladly accepted from those who have the means to do so. Any money donated will be used to purchase seed for next year, so that free distribution of produce to local food banks and directly to local families can continue.