Before I started gardening, I used to think winter squash referred to the squash that grew over winter. Only after harvesting my very first “winter” squash did I realize all the pumpkins, hubbards, butternuts, and turbans that arrived at the turn of cool weather actually took three or four months to get there!
Cucurbita maxima, Cucurbita moschata, Cucurbita mixta, and Cucurbita pepo are summer-growing annuals, maturing through the warmer months and storing through the winter (with some varieties even holding into the following spring).
Though you can use them right away (and what’s more heartwarming than a winter squash roasted to sugary sweetness or blended into delectable creaminess as the weather turns cooler?), you can also save them for two, three, even six months from now with proper curing.
Winter squash differ from summer squash in that they’re picked at the end of the season when their rinds have toughened up, their seeds have fully developed, and their leaves have started to wither.
The leaves are the first sign of fruit maturity. Once they start to yellow on their own and the vines look like they’re on their way out (before frost hits), the squash should be fully ripe. But don’t wait until the first frost! Squash that has been hit with frost will not ripen or store well.
A tan, cracked, and hardened stem that’s died off is a good clue to look at; so is resistance to the stab of a fingernail. You might make a slight dent in the skin, but you shouldn’t be able to puncture all the way through the flesh. The squash should sound hollow when you give it a good thump with your hand, and the skin’s glossy sheen will give way to a duller tone.
At this point, cut the squash from the plant, leaving at least 3 inches of stem. The stem is the fruit’s fail-safe seal against rot and disease, so avoid lifting it by the stem and instead hold it from the bottom.
Despite their burly appearance, winter squash actually require a little babying to keep them from spoiling. Treat them gently while their skins continue to toughen up and the sun heals any cuts or cracks that could lead to rotting later.
A few minor marks on the surface are generally nothing to worry about, but these are the squash that should eventually be eaten first. Same goes for squash that might be bruised or broken; they won’t store well. Squash may also develop ground stains on their skin where they laid on the ground while growing. These superficial spots are merely discolorations and have no effect on the flesh underneath.
Once you’ve harvested all your squash, lay them out in the sun in a warm, well-ventilated area (around 80°F to 85°F is ideal). Mine are simply spread out in the field where they’re not in the way. If there’s a threat of rain coming, move them inside to a dry, cozy place like an attic near a sunny window, a sun room, or a greenhouse, or even a sunny windowsill. Just don’t forget about them!
Winter squash need a good two weeks of warmth and sunlight to properly cure. In that time, the fruit continues to “breathe” but as its skin hardens, the rate of respiration (and thus the rate of spoilage) slows down. The harder the skin is, the longer it will keep in storage. Think of the hardened skin as a protective layer of armor; it makes the squash impervious to mold and bacteria. Curing also concentrates the natural sugars in squash, making them sweeter and richer.
I like to turn my squash over after one week and let the other side soak up some sun for the remaining week. Under cloudy conditions, allow two weeks per side.
Once fully cured, store your squash in a cool, dry, and well-ventilated area with an ambient room temperature below 70°F. Very cold conditions (anything under 50°F) will shorten storage life. Don’t just lump all your squash together into a large bin and call it good; stash them in a single layer on a shelf with ample air circulation, where they’re easy to check on throughout the season. You want to keep an eye out for blemishes and soft spots and use those up first.
The following winter squash hold well with proper curing:
- Delicata (2 to 3 months)
- Spaghetti (2 to 3 months)
- Pumpkins (2 to 3 months)
- Butternuts (3 to 6 months)
- Buttercups (3 to 6 months)
- Turbans (3 to 6 months)
- Banana (3 to 6 months)
- Kabocha (4 to 6 months)
- Hubbards (4 to 6 months)
- Cushaws (4 to 6 months)
In general, the harder and thicker the rind, the longer it will store.
Acorn squash is an exception to the curing rule, as it declines in quality if left in the sun. It keeps (without curing) in ideal conditions for a month or two at most.
Sometimes I’ll get lucky and a squash will store longer than expected. I love to pull out, say, a hubbard in March — a squash that I’d harvested back in August! With only a couple of winter squash plants, you could be set on soups and roasts until the following spring when the weather finally turns warmer.