MIDLANDS - What are cole crops? From where does the name come? Although cole crops are associated with northern Europe, they actually originated in west-central Asia and became staple crops in the cool, moist climate in central and northern Europe. The German and Dutch word for cabbage is kohl, and our language changed this word to ‘cole'. It has come to include now most of the other brassica crops like greens, broccoli, and cauliflower as well as cabbage. These crops can be grown year ‘round, as Lexington County proves each year, but they are primarily looked upon as cool season crops with fall being a prime time for their growth and consumption. Much of this impression comes from the fact that light frosts ‘sweeten' up these crops. This is because, in response to frost, these crops (and many other frost-tolerant crops) move water from the leaves to the roots. This increases the sugar concentration in the leaves which lowers the freezing point of the plant tissue. A side effect of this process is a sweeter flavor. You can do this with summer collards by placing the collard bunches (with leaves still attached to the stems) in the freezer for about ten minutes. This will give you that ‘just frosted on' flavor in July.
Cole crops are growing and producing well now. If they aren't, some of the following facts may point to the reasons why not. Cole crops in general are very particular about soil conditions. They need the pH to be adjusted properly, the seedbed to be prepared properly, and to have very little weed competition during their early growth stages. The best soils for cole crops are loamy soils that hold water and nutrients well, although sandy soils or heavy clay soils that have been properly amended with good quality composts over the seasons will produce good cole crops, also. The pH for cole crops should be around 6.5. A 3:1 ratio between calcium and magnesium is ideal, although, if your crops are growing well don't worry about this ratio. Good full season weed management keeps the number of weed seed in the soil at a minimum. Cultivation or mulching of the row middles keeps these areas weed-free, while pulling weeds (for emerging seedlings) or hoeing around transplants will be necessary to keep the young crops growing well. The row area can be mulched after the plants become established, however pulling the mulch back after the late summer weed season is over will allow the soil to warm and improve growth during the cooler time of late fall and early winter.
Cole crops are usually considered heavy feeders. Additional nitrogen can be applied from a readily available source such as manure/compost tea as the crop grows. Use a readily available source because organic nitrogen sources need to be mineralized. This biological process proceeds much more slowly when the soils are cool in the fall and early winter, so raw sources of nitrogen such as seed meals will give up their nitrogen very slowly. If you use synthetic fertilizers, the majority of the nitrogen fertilizer should be made only after the crop has become established. This prevents unnecessary leaching of the soluble nitrogen compounds before the roots develop enough to take it up.
Cole crops are among the most nutritious crops that we grow. They contain many minerals, vitamins, and other phytonutrients as well as provide much fiber for our diet while being very low in calories. Take full advantage of this healthy group of crops this fall either from your own garden or from the many local sources around Lexington County. Your local extension office has good information on producing and using cole crops; call them.
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