Plant Profile: Brassica napus (Napobrassica Group)

Brassica napus, commonly known as rutabaga in the United States, belongs to the Napobrassica Group. The term "Brassica" is derived from Latin, meaning cabbage. This vegetable is a hybrid of turnips and cabbage, but it is not particularly popular in the U.S. due to its lengthy maturation period, which can take between three to four months. In contrast, turnips can be cultivated in roughly half that time. Nevertheless, rutabagas are generally larger, denser, and sweeter than their turnip relatives.

Although this biennial plant thrives in cooler weather, it is typically grown as an annual. For optimal growth, sow the seeds in your garden four to six weeks prior to the last frost date. Alternatively, you can plant them after the summer heat has subsided for a fall or early winter harvest.

The ideal time to harvest the edible bulb is when it reaches a diameter of 3 to 5 inches, as bulbs larger than 5 inches may become tough. The greens can be picked once they grow to a height of 4 inches. If the top of the bulb remains undamaged during the harvesting of the greens, it will continue to produce new growth.

To ensure healthy plants, provide them with about 1 inch of water each week. Insufficient water can lead to woody and bitter-tasting produce. Interestingly, crops harvested after a dry spell tend to have enhanced flavor, better firmness, and improved storage qualities compared to those grown in wetter conditions.

There are various rutabaga varieties available.

In terms of pests and diseases, the primary concern is clubroot, a soil-borne illness. If clubroot is detected, it is advisable to refrain from planting rutabagas in that area for at least six years. Additionally, flea beetles can harm the leaves, but using row covers can help shield the greens from these pests and prevent moths from laying eggs on the foliage.