There are many more radish varieties that the peppery salad types sold in the shops. The biggest distinction is between fast growing summer types, and the larger hardier winter types that make great ingredients for stir fries and winter casseroles. It is possible to harvest radish from April to December by growing a range of different types. Radish is very easy to grow and is an excellent crop for a novice gardener to start with, whether in containers on a patio or in a vegetable bed.
Summer radish types provide a delicious peppery flavour to salad and are one of the quickest growing crops. The time from sowing seeds to picking can be as little as four to six weeks. They are typically smaller than winter types, and come in a range of skin colours with white flesh. The seeds are sown once the weather starts to warm the soil in the spring, up until the end of August. Sowing a little seed every two weeks will provide a succession of harvests over the summer months. The seedlings should be thinned to a spacing of about 5 – 7 centimetres, or 2 -3 inches.
Winter radish varieties are larger than summer types and take twice as long to reach maturity, about eight to ten weeks. Whilst called winter radish, they can be sown in the spring just like summer varieties and picked as required. The reason they are called winter radish is for their hardiness. Mid-year sowings will be ready at the end of summer, but rather than picking straight away, they can be left in the ground and harvested when needed, right up to the end of the year. Winter radish should be spaced about 15 – 20 centimetres apart, or 6 -8 inches.
Summer radish types make good row markers for slow germinating crops like onions and parsnips. The seeds can be sown in the same rows, but radish seeds will germinate faster. By the time the radish is picked, the onions or parsnips should be coming through. For a tasty crop of radishes, the seedlings should be regularly watered to keep the soil moist. If they experience periods of drought the flesh may become woody, which spoils their flavour.