The produce we grow in our vegetable gardens can be classified into four groups: tomatoes, peppers, eggplants, potatoes, etc. (Solanaceae); cucumbers, squash, pumpkins, etc. (Cucurbits); cabbages, cauliflower, broccoli, etc. (Brassica or Crucifers); and the rest, lettuces, carrots and whatever. The good gardener will avoid sowing any members of these groups in the same garden space that was used immediately before. At least a year should pass, preferably two years, before re-planting but sometimes we just run out of space. Keep the rule in mind, however, and abide by it when you can.
Cucurbits are vinous and in the 60-90 day production category. They tend to be shorter lived than many other vegetables, though pumpkins can stay around for quite a while. This means that Cucurbit seeds such as cucumbers should be sown successively about 4 weeks apart in order to keep the fruits coming. Watermelons are Cucurbits but have a different set of rules from the rest so I will not mention them in this article.
Cucurbits need good drainage and the accepted method of culture is to make slightly raised hills that are enriched with mature compost or animal manure. The hills should be about 18 inches in diameter and well fertilized. Sow three seeds about half an inch deep in a triangle where each seed is at the mid-point between the centre of the hill and the perimeter. Water frequently, even after the plants are established and growing vigorously. Cucumbers and crookneck squash can grow three plants to a hill but zucchini, winter squash and pumpkins should have the best specimen left and the others removed.
Cucurbits produce male and female flowers. The female flower is usually larger and has a juvenile fruit at its base. If you only grow two or three vines you may run into pollinations problems. On the day a female flower opens there may be no male flowers to provide pollen. The more vines you grow, the better your chances. Cucurbits rely upon insects – particularly bees – to pollinate the flowers but sometimes they are not around and you have to do the pollination yourself. Use a Q-tip and dab some pollen from the centre of a male flower, then dab the yellow pollen onto the top of the centre of the female flower. This is best done mid-morning on a dry day because the female flowers tend to fold up after midday and become unreceptive. When a bee pollinates a female flower the flower folds shortly afterwards so any flowers still open in mid-morning are probably in need of pollination. When successfully pollinated the flower will wither and drop while the fruit grows quickly.
Some gardeners complain that cucumbers take up too much space but this problem can be overcome by sowing compact ‘patio’ varieties. The vines are short but the cucumbers produced are full sized. Patio cucumbers – as the name suggests – can also be grown in containers. Cucumbers should be picked when the fruit is smooth and the prickly spines on the skin can be brushed away easily with your fingertips. Do not allow fruits to stay on the vines after this point because the seeds will grow large and tough and make the eating experience less pleasant.
Crookneck and straightneck squash tend not to be vinous and are heavy bearers. Pick the fruits early before large seeds develop and refrigerate them if you have too many at one time. Zucchini plants can grow several feet tall and produce baseball bat size fruits, but this is not what we want. Again, pick early and often. If you are adventurous you may like to sow seeds for summer squashes that grow the size of softballs or are shaped like patty pans.
Winter squash are so called because they have drier flesh and can be preserved for much longer than summer squash varieties. I have found Butternut to be more reliable than Acorn but your experience may be different. Harvest your fruits when you detect that growth has stopped. There is no need to refrigerate winter squash unless you are storing the fruits for months.
The leaves of all Cucurbits are attacked by yeast, mildew, fungus and other spores that stick to them while they are covered in dew at night and grow in the warm daytime sun. There are fungicides available that can help but need to be applied before the problem arises. Some gardeners swear by spraying the leaves with milk.