A polytunnel is very useful for growing squash and pumpkins. Often, they will grow better and get larger in a polytunnel than they will do if grown outside. A polytunnel can also increase the range of squash and pumpkins that you will be able to grow where you live. New polytunnel gardeners often ask how to tell when squash and pumpkins are ready to harvest. So this article will aim to answer that common question:
The Difference Between Summer Squash and Winter Squash and Pumpkins
When it comes to deciding when to pick squash and pumpkins is to understand the difference between summer varieties and winter varieties. The general rule is that summer squash, like courgettes, are best picked when young and tender. You should pick summer squash before their skins harden and before the insides get pithy and full of seeds. Summer squash and courgettes can grow extremely quickly in warm weather, so it is best to err on the side of caution and harvest earlier rather than later.
Winter squash, on the other hand, are generally left to mature fully before they are harvested. These winter squash are hard-skinned and can be stored over the winter months in a cool, dry place.
Harvesting Winter Squash and Pumpkins
Usually, you can leave winter squash on the vines until the leaves begin to die back. However, there are certain signs that will tell you that your squash or pumpkins have reached maturity and that they are ready to harvest. For example, on butternut squash and most pumpkins, they will be ready when the outer skin is too hard to dent with a fingernail. You can also tell when many squash and pumpkins are ready to harvest by paying attention to the colour. The glossiness will tend to dull once they are fully mature.
Don’t worry if there is a frost, as winter squash and pumpkins will often taste better once they have been exposed to a frost or two. You will not have to worry about harvesting them early unless you believe that the temperature in your polytunnel will fall below about -5 degrees Celsius.
There is a huge variety of winter squash and pumpkins and most make excellent polytunnel plants. Though they can take up a lot of space, they can be grown vertically to make the most of the space you have undercover. Another good thing about winter squash and pumpkins is that they will keep over the winter months, helping you to enjoy a varied and healthy diet even through the leanest part of the year.
Do you grow squash and pumpkins in your polytunnel? Let us know about all your successes and failures in the comments below. If you want to know more about growing these crops and others, check out our grow guides to learn more.
Elizabeth Waddington is a writer and green living consultant living in Scotland. Permaculture and sustainability are at the heart of everything she does, from designing gardens and farms around the world, to inspiring and facilitating positive change for small companies and individuals.
She also works on her own property, where she grows fruit and vegetables, keeps chickens and is working on the eco-renovation of an old stone barn.