Growing Squash (the Cucurbit family)

The squash family includes cucumbers, melons, gourds, watermelons, bitter melons, horned melons and gherkins as well as all the summer and winter squashes. They all come from places with hot summers, and they all thrive in heat. In gardening, it's useful to separate the squashes--large plants that originated in North and South America--from the other cucurbits of Africa and Asia. They respond to different garden strategies.

Squash seems to love growing in a compost pile. This tells you three things: It likes a lot of nutrients. It isn't picky about how fine the soil or how "finished" the compost--it will grow in stuff that's downright chunky and stinky. And it sprouts best in warm, moist places.

If you add lots of compost, or bury kitchen waste, manure, or other nitrogen source a foot deep under the seeds, they will love it. Plant in clusters, called hills, of 3-5 seeds. Bush varieties can go 2-3 feet apart, vines 4-6 feet apart. If you use beds, run the hills down the middle of the bed. If you use rows, make them about 6'  apart. If you are planting vining types and need to get barrows, carts, or tillers between, use rows 12' apart.

After the sprouts are a few inches tall, thin to the best 3 plants per hill. Hoe out all the weeds in the bed or row, piling some dirt at the base of the plants. Mulch well with straw, leaves, hay, or piles of weeds you just pulled. Use whatever you have that can keep the soil covered and provide a steady diet of organic matter. Vining squash can be grown up a trellis to save space, or they can be planted at the edge of the garden where they can run out over a rough, paved, or unirrigated area outside the growing beds. Do not let them grow so close to corn that they try to climb it--they'll pull the stalks down. You can let the vines run amid corn, sunflower, or amaranth stalks as long as you don't let the tendrils start trying to climb the stalks--just snip any clinging tendrils. Most summer squash has a bush habit, which is compact and saves space, but is not as vigorous or drought-resistant.

Speaking of drought, you will probably see squash leaves wilt and droop a bit in hot sun. This is a water-saving measure. Rather than try to keep their big leaves turgid and flat which would take a huge amount of water and hydraulic pressure from the roots, they let them droop a bit to reduce the surface area and change their angle so they're not facing the sun directly. If the plants are truly thirsty, the soil will be dry 1" down, and the leaves won't perk up when the day cools. If the leaves look normal again once the sun is off of them, they don't need extra water. The rough, hairy surface of squash leaves and stems is another water-saving measure--it minimizes evaporation from the leaves by slowing the flow of air past the surface.

If squash bugs are a problem for you, sprinkle the base of the plant and all the main stems with diatom dust.

All squash have separate male and female flowers on each plant. The female flowers have a small bulge or ball below the flower; this will turn into the squash fruit. Male flowers are on a longer stem with no solid ball at the base. They make pollen but no fruit. You can harvest them for the kitchen--they're edible and delicious. Use just the yellow petals (the green parts are bitter) in pasta, tacos, soups, or stuffed.

Summer squash should be picked every day or two, and eaten while small (6"-8".) The reason people complain about having too many zucchini is that they let them get too big. Store squash in a dry place. Even zucchini keeps better in a dry airy room than in the fridge, where it molds.

​Winter squash is ripe when there is no green left in the stem--it should be hard and woody or corky--and the skin should be too hard to poke with a fingernail. Regardless of ripeness, harvest before frost or they will rot. Use any unripe or bruised ones first. The rest should be put indoors to cure for a month before eating. Delicata squash and pumpkins (C. pepo species) do not store as long, or need as much curing. Cure 2 weeks and eat before January. Squash can be stored in any dry place that stays above 50 degrees. Check often for soft spots, and don't forget to use them for soups and pasta as well as roasted and in pie.

Squashes were not originally edible; they were horribly bitter, (to deter animals from eating them) and mostly provided moisture and compost for the seeds to grow in. The original human uses of these plants were for containers (gourds) and for their protein-rich seeds. It probably took centuries of patient work for the ancient farmers to transform those bitter seed envelopes into the sweet and delicious squash we grow.

Breeding has also produced the summer squash, which were selected to be stay soft and free of hard seeds for longer than normal, so they have a longer window for fresh use. They will eventually grow a hard shell and mature seeds, but they are no longer palatable at that point. Winter squash are meant to be grown to maturity, with sweet flesh surrounding a cavity full of hard, mature seeds. The lower-moisture flesh and hard shell of winter squash types enable them to last for months at room temperature, making storage easy for winter eating. That said, I have stored large semi-mature zucchini (called vegetable marrows in England) for a couple of months. They weren't prime zucchini, but they were fine in pasta sauce and soup.

Seed saving: Insect-pollinated, requires at least 500 ft isolation in home gardens (1/2 mile if selling seed.) Our offerings include 3 species: Cucurbita pepo (pumpkin, delicatas, acorns, and most summer squash), Cucurbita maxima (Buttercup, Lower Salmon River, Stella Blue, Zapallo), and  Cucurbita moschata (Butternut, Tromboncino.) Members of the same species will cross with each other, but not with other species. So if you have the isolation to grow squash seed, you can have one of each species and still save seed. ​

Cucumbers, melons, and watermelons are members of the squash family from India, Persia, and Africa. Their vines are on a smaller scale than squash, with less rampant habit. They prefer a lighter, more cultivated soil than the big squashes and their sparser vines don't shade out weeds like the larger squashes do. You will need to mulch or weed the bed to prevent weed competition. All of them love heat and are adapted to dry climates. Originating from the desert, they are adapted to a rhythm of hot days and cold nights, but they will not sprout until the soil is warm. I usually wait until 2 weeks after my last frost date to direct-sow. I find that cucumbers (from India) enjoy a bit of afternoon shade, needing heat but not blasting sun.

Melons, on the other hand, are sun-lovers that thrive in a heat. The history of melons and watermelons goes so far back it's hard to tell what they were like originally--we know that the ancient Egyptians ate watermelon 4,000 years ago. None of these plants resemble their small, unpalatable wild ancestors; all were transformed by the breeding work of ancient farmers.