Pumpkins, squash and zucchini
These three groups of vegetables (and a few others) belong to the Cucurbita genus. Photo: Sol Morgan
The summer vegetable garden just isn’t the same without a pumpkin, squash or zucchini. These three groups of vegetables (and a few others) belong to the Cucurbita genus, which contains 27 species of vigorous trailing and climbing annuals and perennials. They are closely related to cucumbers (Cucumis sp) and melons (Citrullus sp).
Originating in North and South America, they have formed an important food crop for many cultures around the world, and still do. The husks are also used as mixing bowls, water containers and livestock feed. Cucurbit remains have been found in Mexican settlements dating back to 8500BC.
Pumpkins (or winter squash in America) are divided into two species, Cucurbita maxima and C. moschata. C. maxima species contain probably the largest selection of pumpkin varieties, including Crown Prince, Whangaparaoa Crown, Queensland Blue, Hubbards, Jackpot, Red Kuri, Triamble, Sweet Dumpling and Buttercup. C. moschata includes Butternut, Long Island Cheese and Golden Cushaw.
C. pepo is the species that contains squash and zucchinis. Squash in this case is called Summer Squash in America. C. pepo includes zucchini (in Italian) or courgette (in French), scallopini, acorn, Turk’s Turban, kumi kumi and spaghetti squash. As far as zucchinis go, there’s the compact Black Beauty, Gold Rush with yellow fruit, Zephyr bicoloured, Costata Romanesco and Cocozelle (both Italian heirlooms). The last two are larger plants that may need more room, but they make up for it with superior-flavoured large fruit. Of course if you forget to pick a zucchini, you’ll quickly end up with a marrow (but these are still very edible).
These crops like sunny but sheltered positions. Pumpkins and some squash like spaghetti squash need quite a bit of room. Try planting them beside the compost bins, climbing along a fence or other structure, or amongst the fruit trees as a ground cover. Traditionally they are grown in combination with beans (nitrogen fixers) and corn (maize), where they shade the ground, thus conserving moisture.
Cucurbits like a rich, moist soil so feed your ground with plenty of rotted manure, compost, vermicast and supplement with blood and bone or fishmeal. In fact the best pumpkins often self-seed straight out of the compost bin. Liquid fertilising weekly helps provide both nutrients and much-needed moisture for good, strong growth.
Once the ground is prepared, make a small mound with a depression in the middle. Transplant the seedling into the depression, and water. From about November it’s safe to sow seed directly into mounds. Plant at least three and select the strongest. The mound will help raise the soil temperature and the depression collects water.
Allow about one metre between plants. I usually plant only one zucchini in November and another in January as a late-maturing one, particularly a mildew-resistant variety, provides plenty of fruits into April/May.
As far as seed-saving is concerned, the important thing to remember is what defines a species. That is, a species is a group of interbreeding plants. If you grow a crown and buttercup pumpkin in the same garden, they’re likely to be cross-pollinated by bees, and you will get seed variations next season. You will, however, get something edible, and it’s in this way that we breed some crops by accident! If you’re isolated from your neighbours (about a kilometre) then you can safely save true-to-type cucurbits. If you’re not isolated, but keen to save true seed, try hand-pollinating some flowers. Both male and female flowers are present separately on the same plant. The female flowers have the swollen ovary and are usually lower down. Tape up both male and female flowers the day before, when the flower is going slightly yellow. The next day, untape the male flowers first. Remove the petals so the anther (the bit with the pollen) is showing. Then, armed with a bunch of these, untape each female flower in turn and rub in a bit of pollen from each male flower. Retape, and mark the pollinated female flowers. Continue this process for several days to ensure success. If pollination is successful, the female flower will quickly turn into a growing pumpkin that will contain true-to-type seed.
Later in the season, as the fruits mature on pumpkins and squash, it’s important to time the harvest well. They’re ready to harvest when both fruit stalk and the tendril near the stalk are browning off. Cut the stalk with secateurs, leaving about 2.5cm. Store pumpkins in an airy, cool, dry spot, well protected from rodents. A netted cage or having a cat works well.
Cucurbits’ culinary uses are incredibly varied. They’re definitely worth the effort.
Sol Morgan
