Green Hokkaido Winter Squash

The seeds of winter squash germinate best with some warmth. I sow mine in modules of seed compost in the first half of May and normally keep them in a propagator between 18-21 degrees.   This year, spring was unusually warm, so they germinated fine just in my potting shed.   You can sow them anytime from mid-April till the beginning of June depending on local conditions.  If there are mice around, cover them up before they germinate, as rodents love the seeds, and once they have germinated, keep them somewhere nice and light to stop them getting thin and leggy.    There’s a danger that if you sow them too early, they’ll get too big in their pots before it’s warm enough outside for them to be planted out, so don’t be tempted to sow them any earlier.  Once germinated, they can be potted on as soon as they’re big enough, then planted out, after hardening off, when they have three ‘true’ leaves.  They don’t like cold nights and really hate the wind, which can be common in late spring early summer.  If they’re outside and weather’s not kind, early plants will just ‘sulk’, with later sowings catching up in no time.   We screw together old windows to create a micro-climate round our plants, protecting them from the wind, and they really thrive in them.  If it’s wet spring and you’re prone to slugs, they may initially need some additional protection, as slugs love baby squash plants.  They’re hungry feeders so give them plenty of organic matter when you plant them out, and regular watering and feeding throughout the season.  

When the fruits get larger, place something hard underneath each one to lift them off the damp ground to prevents rotting and damage by slugs and snails.  Also make sure they are exposed to full sun to aid ripening, cutting off a few of the leaves if necessary.  Harvest when the leaves have died back, or before the first frost, then lay them out in the sun for an additional week or two to harden the skin and ensure they store well.  Store anywhere that’s well-ventilated and that’s between 10–15 degrees, checking regularly for any signs of deterioration.