"Squash is something you can grow just about anywhere in the country below the treeline," says Chris Chechak, farm trial co-ordinator for Stokes Seeds in St. Catharines, Ontario. The biggest mistake gardeners make is planting seeds too early, she says. Soil temperature, usually 5 to 6°C cooler than the air temperature, should be at least 18.5°C, or warm enough to sit on comfortably. "If the ground is cold and wet, the seeds will rot very quickly, even if treated with anti-rotting agents," Chechak says. Soil can be pre-warmed by covering the area with black landscape fabric or plastic. Old tires, though unsightly, are perfect for growing squash when placed around seedlings — warming the ground and helping to contain the vines. Use organic mulch under the plants and as far as the vines extend along the ground; fruit resting directly on damp soil may rot. Water weekly, or bury soaker hoses under vines; squash require about six centimetres a week. Don't water at night; plants and soil need time to dry out, or they could develop powdery mildew.
Maturity dates are important in determining what to grow. Larger, longer-maturing varieties such as 'New England Blue Hubbard', which takes 110 days to mature, may have to be set out as seedlings in some areas. Smaller vining varieties such as 'Ambercup,' weighing 1.5 kilograms or less, can grow vertically; drape or tie vines on a trellis. Those without grasping tendrils must be tied. Support fruit with slings made of fabric (old pantyhose or J-cloths work well) tied to the trellis; don't use wire or twist ties, which can sever the vines. Be sure the fabric and trellis, not the vine, take the weight of the growing squash. Vines can also be trained up wire fencing, a lean-to, tall wooden arches, tripods or teepee-shaped frames.
Not all squash blossoms grow into fruit; don't be alarmed if some just drop off. (Squash blossoms are edible: early blossoms dipped in batter and deep-fried are delicious.) To keep vine growth in check, pinch off the growth tips once fruit has set. (Grandma came up with her own space-saving solution during the Great Depression: according to family legend, she trained squash vines up the drainpipes and onto the roof to conserve space — the entire backyard was already under cultivation.)
Harvest squash when the skin is hard (not easily dented by a thumbnail), after the first light frost. Frost improves taste but can reduce storage time in some varieties. Cut the stem 10 to 15 centimetres from the fruit with a sharp knife. Cure in a warm, dry place, about 24°C, for 10 to 15 days, then store in open bins in a cool, dark place at 10 to 12°C with plenty of air circulation. Place fruits in single layers, not touching each other. Squash should last two to six months, depending on type.
Be on the lookout for squash vine borers — fat, wrinkled, white caterpillars that tunnel into the squash stem, causing the vine to wilt and die. Slit open the vines, pry out the borer and kill it. If the vine isn't too badly damaged, bury the slit-open part; the vine should re-root at that point. Fusarium wilt, bacterial wilt, powdery mildew and downy mildew can also be problems; choose disease-resistant varieties. Rote-none, an organic insecticide, is also effective; follow package directions.
If you'd like to save your squash seed for next year, be warned: squash cross-pollinates with other squash and pumpkins, so you can never be sure that you'll reap what you sow. Plant different squash cultivars as far away from each other as possible.
I've faced other squash-growing challenges in the past, mainly the furry kind. A few years ago, I ordered a packet of 'Golden Hubbard' squash seeds, but squirrels ate them before they even germinated. I then tried planting seeds saved from last year's 'Mini Green Hubbard' and from the sole-surviving 'Small Sugar' pumpkin. Nothing came up. Finally, I bought some 'Early Butternut Hybrid' seedlings and a pumpkin of indeterminate variety from my local gardening centre. It wasn't what I'd had in mind, but it was better than being squashless, or eating the store-bought variety. Cracking open my own homegrown squash in the dead of winter has become something of a ritual. It's like being able to save some sun — not just from the previous summer, but from childhood itself.