Broccoli (Brassica oleracea var. italica ) is a delicate, low-maintenance cabbage with fine flower buds. This is how to plant, care for and harvest the vegetable properly.
Origin of Broccoli
Broccoli, like cauliflower, belongs to the crucifers or cabbage family (Cruciferae). Originally from Asia Minor, it has been cultivated in Europe, especially in Italy and France, since the 16th century. It is believed that both broccoli and cauliflower are descended from the plant Brassica cretica, which grows wild in southern Greece including Crete and in southwestern Turkey on coastal cliffs. Broccoli can be bought all year round, but it is still worth growing your own, because unlike its close relative, cauliflower, the buds harvested just before flowering cannot be stored for long. The florets quickly become soft and lose not only a large part of the vitamins they contain, but also their firm bite. Another reason for growing broccoli yourself is that it grows much faster and makes fewer demands on care than cauliflower.
Appearance and growth
Unlike cauliflower, broccoli does not develop a closed inflorescence, but rather large leaves that sit on long, fleshy stalks and green or purple flower buds in loose heads. Broccoli is a relatively uncomplicated cabbage that can be harvested almost year-round. This is because its shoot axis replicates new side shoots with flower buds after pruning.
Two types in particular are of interest to amateur gardeners: the summer and autumn broccoli, which originate in Italy, and the particularly cold-hardy varieties bred in England, which are known as winter broccoli. With a clever choice of varieties, you can therefore also harvest all year round. The latter, however, is winter-hardy in temperate climate only in mild winters.
Location and soil
Broccoli grows best in deep, nutrient-rich soil with good water retention capacity in a sunny spot in the vegetable patch. Since broccoli prefers a higher lime content, the soil should be supplied with algal lime in the fall.
Crop rotation and mixed cropping
Like all cabbages, broccoli thrives in a versatile mixed crop. Beans, dill, beet and endive lettuce, but also chard, leek, celery, radishes or small radishes are suitable bed partners.
If you want to grow broccoli from seed, you need a little patience, because it takes at least 30 days from sowing to the seedling ready for planting. Early varieties can be preplanted from January to March in seed trays containing humus-rich seed soil. The ideal germination temperature is 15 to 20 °C (59 to 68 °F).
If you want to grow many cabbage plantlets, use space-saving multi-pot planters. After germination, the seedlings should be pricked out into single pots measuring 5 centimeters (2 inches). From around mid to late May, you can also sow directly into the bed. Use three seeds per planting hole. After germination, you then leave only the strongest seedling at a time. The planting date for winter broccoli is in August and September. It is then ready for harvesting in April to May.
As soon as the young plants have rooted the root ball well and have formed three to five leaves, they can be transferred to the open ground under fleece from April. Plant them deep enough so that the root base is covered with soil for about one centimeter (0.4 in). The planting distance is 40 to 50 centimeters (16 to 20 inches). A generous application of compost (three to five liters per square meter) when preparing the bed will ensure a good start. Algal lime (about 30 grams per square meter) covers the high demand for calcium and provides important trace elements such as magnesium.
Caring of broccoli
Broccoli requires regular watering and nutrients. After planting, it is important to water the cabbage vegetables well. Water sparingly for the next two to three weeks, then more generously again. You should also hoe frequently and mound the plants regularly. To ensure that the nutrient-hungry cabbage develops well and forms many side shoots, administer a liquid vegetable fertilizer or nettle manure about six weeks after planting or before bud formation begins. This prevents growth stagnation.
An exception is winter broccoli. Since it is supposed to grow slowly, you should feed it rather sparingly with horn shavings or organic vegetable fertilizer. A second fertilization should be postponed until spring, because nutrients given in the fall will impair frost hardiness. Especially for winter broccoli, it is important that the plants grow slowly and form firm leaves, because only then they can survive a few sub-zero temperatures without damage.
Diseases and pests
The larvae of the swede midge (Contarinia nasturtii) destroy the central bud and cause stunted growth, as their saliva contains growth-inhibiting substances. The solution is a close-meshed vegetable net or fleece and cultivation in wind-open locations. The vegetable net also prevents damage by aphids and cabbage flies. A mixed culture with non-ranking varieties of nasturtium can prevent infestation with the caterpillars of the cabbage white butterfly. A growing break in the same bed of at least four years to all cabbage varieties can prevent root diseases such as clubroot. Add a portion of algal lime directly into the planting hole already at planting, this also serves as prevention.
Harvest and use
After about seven weeks you can harvest broccoli, but varieties planted in the fall need at least ten weeks. With winter broccoli, it takes almost half a year before harvest, but you can continuously cut shoots from March to May. You can recognize the right time for harvesting by the fact that the individual flower buds are clearly pronounced and swollen, but still quite tightly closed. If the flower is already becoming loose and showing a yellow sheen, the buds will taste unpleasantly cabbage-like. Cut off the inflorescences that are still closed with a sharp knife. The thinner side shoots can also be utilized. After the center buds are cut, thinner side shoots, called “side roses,” will grow back again.
Broccoli can be prepared in no time at all and enjoyed in a variety of ways . Whether as a creamy soup or a crunchy raw vegetable. For example, the vegetable can be boiled, roasted, steamed, baked, or simply eaten raw. In addition to the florets, the stalks can also be cooked. The stalk can be peeled with a peeler and eaten as well. After harvesting, you should use the vegetable as soon as possible. You can store broccoli in the refrigerator for two to three days at the most. You can also freeze your broccoli. In that case, however, you should blanch it beforehand. The sprouts from broccoli can be used as microgreens in the kitchen.