To successfully grow Cauliflowers
you'll need rich, deep soil and the real trick is to make sure there are no ‘checks’ to growth so care must be taken with soil preparation, planting and watering Cauliflowers are part of the Brassica family of vegetables. Although some root veg are classified as Brassicas, the term is usually reserved for those veg we grow as ‘greens’, such as cabbage, sprouts and broccoli.
Soil & Growing position
All brassicas prefer a reasonably sunny spot and firm, rich ground so dig in some organic matter such as Farmyard Manure or compost, during the winter prior. Cauliflowers appreciate a well-consolidated soil and dislike freshly manured soil so a period of time needs to pass between digging and planting. Mulching around the growing plants will help to retain moisture. Remember to plant any veg of the brassica family in a different patch of soil each year to stop the build-up of diseases such as clubroot (see Soil Preparation and Crop Rotation). If you have very acidic soil, add in some lime during the winter as this will also help to control clubroot. You can test your soil’s acidity by using a Soil Testing Kit. Brassicas are quite nitrogen hungry so they thrive in ground where peas and beans have previously grown (see Crop Rotation). Apply a general fertiliser to the soil a couple of weeks prior to sowing or planting.
Summer varieties can be started off under glass in January and transplanted outdoors in late March/early April for a June/July harvest. Alternatively, they can be sown outside from early April, transplanted in June for an August/September harvest. Autumn cropping varieties can be sown outside between mid April and mid May for transplanting in late June. Winter cropping varieties can be sown in May for transplanting in late July.
Sow thinly 13mm (0.5in) deep in a seed bed in rows 15cm (6”) apart. When large enough to handle, thin the seedlings to 7.5cm (3”) apart to prevent them becoming spindly and weak.
The main sowing period is March to May, although early crops can be achieved by sowing under glass in January/February or sowing a suitable cultivar in the autumn.
Growing on and Young Plants
Transplant the young plants to their growing position when plants have five or six leaves. Water well the day before lifting the plants and again after transplanting. Lift the seedlings carefully, retaining as much soil around the roots as possible and plant firmly. As brassicas prefer a firm soil, do not fork over the soil before planting. Instead lightly rake the surface and tread down the soil prior to planting.
Space summer and autumn cropping varieties 60cm (24”) apart and winter ones 75cm (30”) apart. If you are short of space, plant closer together (minimum 6”) to produce mini caulis.
Hoe regularly to keep on top of the weeds. Watering needs to be consistant as cauliflowers must not be kept short of water particularly in the early stages, otherwise small heads will develop. Feed with a liquid feed. Use Cabbage Collars around the plants to stop cabbage root fly. Keep an eye out for pests such as caterpillars and aphids. Spraying at the first sign of attack is recommended. Birds can be a problem, so use netting. Covering the crop under micromesh or in growing tunnels is an easy and organic way to protect your young crop from the risk of birds, caterpillars and aphids.
Bend a few leaves over the heads during summer to protect them from the sun and similiarly, with winter varieties break a few leaves over the curds for protection from snow and frost.
Earth-up the stems of spring cabbage during the autumn and firm in any plants that become loose from wind or frost during the winter.
Start cutting when the heads are still firm, before the florets start to separate. Don’t wait until all the heads mature, start cutting when some of the heads are still small otherwise you’ll have a glut of cauliflowers all in one go. Caulis are best cut in the mornings when there is still some dew on them but wait till midday if the weather’s frosty. Heads can be stored for up to three weeks before use, by lifting the plant, shaking the soil off the roots, hanging the whole thing upside down in a cool place and misting the heads occasionally.