Zucchinis have become common in cool temperate climates, but they have always been an essential vegetable in Mediterranean cooking – especially Italian dishes. They are a delicacy when they are home grown, because you can cut them while they are tiny and use them immediately, while they are fresh. In fact, it is best to harvest zucchinis while they are small, because the plants have a self-regulating mechanism that limits the number of fruit each produces. If the small fruits are left on the plant they will turn into marrows and prevent the formation of more.
Propagation
In late spring, after all danger of frost is past, you can plant seeds directly where they are to grow. However, it is easier to sow some seeds in small pots and grow them under cover until three or four true leaves have formed on each. They can then be transplanted. Alternatively, well-grown seedlings are available in spring from garden centres.
Soil and site
Zucchinis prefer a sunny open position. They will grow in most soil types, but a soil that has been enriched with organic matter like compost, together with a general fertiliser, will produce best results. The soil should retain moisture but not become waterlogged, since roots will rot in soil that stays permanently wet. The plants will eventually trail and cover a space about a metre (three feet) or more in diameter, so two or three plants are enough for an average garden. Put the young seedlings in individual mounds of soil to allow plenty of space for root growth, and surround with a mulch of straw, to conserve moisture.
Pollination
In cool or overcast conditions, pollination may not occur. The bright yellow zucchini flowers are usually pollinated by bees, but they can be hand pollinated to speed up the process. The male flower can be distinguished because it is smaller than the female flower and does not have a small bump at its base. It can be used to pollinate a number of the larger female flowers by plunging it and its pollen into the female flowers.
Care
Make sure fruits are kept off the ground to discourage slugs and snails. Water should not be allowed to pool around the main stem, which rots easily. Irregular watering can cause embryo fruit to fall off the plant.
Harvesting
Cut the fruit with a sharp knife when they are 10 to 12 cm (four to six inches) long. Though best eaten fresh they can be stored for up to a week in a cool dry place. Larger marrows have a thick skin and can be stored longer.
Nutritional value
Zucchinis are mostly water and some carbohydrate, but they also contain Vitamin C, folate and zinc. They have many culinary uses, notably in ratatouille, in salads, or dipped in batter and fried.
