Weymouth, Mass. — A regular favorite on the summer and fall dinner menu in our house is kohlrabi, which arrives at the table steamed, with a litter butter, creamed, or au gratin. It also goes into stews, soups, and raw in salads.
Since we discovered the advantages of stir frying, it makes it to the table that way as well. But, best of all is to pull one from the garden and eat it then and there -- minus the peel, of course. In short, kohlrabi pleases the palate whatever way you decide to serve it.
I don't recall who first introduced us to this small-apple-sized vegetable; but whoever it was, he or she has earned our lasting gratitude.
In the garden it disdains both heat and cold to a greater degree than most vegetables, and it grows from spring to late fall in this area. It is also relatively free of pests.
On the other hand, its hearty appetite should be appeased with a generous supply of compost or aged manure, watered well once a week, and thinned to between 4 and 6 inches apart if it is to reach peak flavor and be its tender best.
In case you are unfamiliar with kohlrabi, it is a member of the cabbage family and is grown for the ball-shaped stem it produces when mature. In fact, it is often described as a "turnip growing on a cabbage root."
The bulbus stem is mildly cabbage cum turnip in flavor and folks who say the turnip is too strong for them often enjoy kohlrabi.
Mix aged manure or compost into the planting soil along with a sprinkling of bone meal or a sprinkling of 5-10-5 and superphosphate if you wish to go the artificial fertilizer route. In this latter case you should add some milled peat moss to increase the water-holding quality of the soil.
Some books recommend sowing the seed one-half to 1 inch deep; however, I have found the germination to be best when the seed is planted under a sprinkling of soil to which is added an equally thin straw mulch to shade the soil and keep it moist.
The young seedlings appear to have little difficulty pushing up through the mulch.
Another method is to cover the newly sown seeds with a piece of burlap which has the same effect as the mulch. Check under the burlap each day, and when a majority of the seedlings have sprouted, remove the burlap in the evening.
Once the seedlings have reached a few inches in height I add a light mulch of shredded leaves (other organic materials would do just as well), increasing the thickness to about an inch as the plants grow.
This mulch excludes weeds and keeps the soil cool and moist, two conditions the kohlrabi enjoys. Until the mulch is applied a little weeding may be necessary.
Thinning is necessary to get good bulb development, but don't waste the thinnings. I usually remove them when they're about 3 inches high by snipping with a pair of scissors. At this stage the thinnings make nutritious greens, either cooked or raw. Another option is to transplant some of the thinnings. This has an additional benefit as well. Because thinning sets back the seedlings, the transplanted kohlrabi will mature later than those left in place, thus spreading the harvest over a longer period.
Applications of a manure or compost "tea" every week or so, once the stems have begun to bulb out, helps a lot. Put a couple of shovelfuls of manure or compost in a burlap bag and let is soak in several gallons of water for about three days. Draw off the muddy liquid and add more water until it has the appearance of light tea. Then feed it to the young plants.
Harvest the kohlrabi when it is about the size of a golf ball on up to small apple size. Some gardeners let them get to the size of a baseball, But these tend to be less flavorful and succulent.