Growing Squash from Sowing to Harvest

26 April 2019, written by Benedict Vanheems

Squashes and pumpkins are among the most thrilling vegetables you can grow. One minute the seedlings are tentatively pushing through and then, just a few weeks later, they’re great sprawling monsters with masses of leafy growth and plenty of fruits. I love the fact they’re so easy to grow too – as long as you can keep up with their insatiable appetite that is!

So let’s find out the very best way to grow them...

Summer Squash vs Winter Squash

Squash varieties come in all sorts of shapes, patterns and sizes, but fall into one of two categories: winter squash or summer squash. Winter squash are harvested in one go at the end of the growing season for a feast of fruits to enjoy over the winter months. They include favourites like butternut squash, spaghetti squash and the myriad of pumpkins. Summer squash are harvested throughout the summer and include, for example, zucchini, and patty pan and crookneck squashes.

Squashes are either trailing or bushy. Trailing squash can be left to sprawl over the soil surface or trained up trellis or wire mesh. For really big pumpkins though, it’s best to leave stems to sprawl. They will send down extra roots as they spread to take up even more of those valuable nutrients and moisture.

“Different — Summer squash is available in a wide range of shapes and sizes

Where to Grow Squash

Squash love a warm, sunny and sheltered spot – ideal conditions for good pollination and proper fruit development. The plants are hungry feeders and need a rich, fertile soil. Any soil can be improved by barrowing on lots of well-rotted compost or manure. Or create planting pockets by digging out a hole for each plant at least two weeks before sowing or planting. Fill the hole with a mixture of soil and compost or manure and top with a handful or organic fertiliser.

Smaller varieties of summer squash may also be grown in containers that are at least 18inches (45cm) wide.

How to Sow and Plant Squash

Sow squash directly where they are to grow after your last frost date. Sow two seeds to each position then thin the seedlings to leave the strongest. Pop a jar, cloche or cold frame over sowing areas to help speed up germination.

A more reliable alternative is to sow into pots under cover. Sow one seed per pot, about an inch (2cm) deep. Germinate in the warmth, at around 60-68°F (15-20°C). Sowings like this can be made up to a month before your last frost to give good-sized plants by planting out time. You may need to pot the quick-growing seedlings on into larger pots before it’s safe to move them outside.

Most garden stores and nurseries also sell ready-to-plant seedlings – handy if you only want to grow a few plants.

Set your plants out after all danger of frost has passed. Start to acclimatise them to outside conditions two weeks beforehand. Leave them out during the day for increasingly longer periods then, from the second week, overnight in a sheltered position. Plant trailing varieties up to five feet (1.5m) apart and bush types about three feet (90cm) apart. Thoroughly water plants into position to settle the soil around the rootball.

Growing Squash

Keep plants well watered to encourage rapid growth. You can make watering easier by sinking six-inch (15cm) pots alongside plants. The pots will hold onto the water and deliver it through the drainage holes directly where it’s needed, at the roots. Mulch around plants with organic matter to help lock in valuable soil moisture and contribute additional nutrients.

Stems of especially vigorous varieties can be pegged down at regular intervals to keep them within their allotted space. Larger fruits, particularly pumpkins, should be lifted off the soil, for instance onto tiles, to stop them rotting as they develop.

“Curing — Cure winter squash after harvesting to enable longer storing

Harvesting Squash

Harvest zucchini and summer squash as soon as they are the size you need. Pick often to encourage more fruits to follow. Winter squash and pumpkins are harvested in the fall before the first frosts, usually when the foliage has started to die back or become infected by powdery mildew.

Cut either side of the stem to leave a T-shaped stub. Avoid the temptation to use the stem as a handle as it could detach from the fruit and serve as an entry point to rot. Move fruits to a warm, dry and sunny spot to cure. Curing hardens the skin ready for storage. If it’s already turned cold and damp outside, cure fruits in a greenhouse or on a sunny windowsill. Winter squash and pumpkins will store for up to six months at room temperature.

And there you have it – growing squashes to be proud of is really very straightforward. As always, we welcome your experience of growing these rambunctious veggies – drop us a comment below to tell us what varieties you recommend and to share your tips for growing bigger, bolder fruits.