Winter squash is grown not for a quick summer crop but for the storeroom — thick-skinned fruits that cure hard and keep for months through the cold. It needs a long, warm season and plenty of room to ramble, so it goes in early and is left to run until the rinds harden and the vines die back in autumn.
Direct sow after last frost once the soil has genuinely warmed, or start indoors three weeks ahead and transplant with care, since the roots dislike disturbance. Harvest before the first hard frost when the skin resists a thumbnail, leave a couple of inches of stem, and cure the fruits in a warm dry spot for a week or two before moving them to cool storage. Properly cured, most types keep well into winter and many sweeten as they sit.
Powdery mildew
White or grey powdery coating on leaves — usually starting on older growth in humid conditions or when nights cool.
Improve air circulation by thinning plants. Apply neem oil or potassium bicarbonate spray at first sign. Avoid overhead watering.
Downy mildew
Yellowing on top of leaves with grey-purple fuzz underneath. Spreads rapidly in humid conditions.
Remove affected leaves. Improve air circulation. Avoid overhead watering. Copper spray as preventive.