This plant has been domesticated since over 10,000 BC. Hardly any other vegetable comes in such an incredible variety of cultivars. You can grow squash in all sorts of shapes, colours and flavours. That also means a huge range of ripening times.
Some varieties you can already enjoy in summer, as you can keep harvesting them unripe — like the UFO-shaped pattypan squash or courgettes.
Others, like the Hokkaido, you can harvest as early as late August, at the start of autumn.
Then there are slower-ripening varieties, like certain butternut squashes that you can only pick from the bed in early October. Make sure to bring in the last squashes before the first frosts, though.
And of course, squashes are hugely popular as autumn and Halloween decorations.
Facts and figures
Planting & harvest times of Squash
Planting 1Direct sowing from Mid May to Early June. Transplant to bed from Mid May to Mid June. Pre-grow about 25 days before transplanting, approximately between Mid April and Mid May. After a growing period of 120 days, harvest can begin around Late August and continues until Late November.
Planting 2Direct sowing from Mid May to Early June. Transplant to bed from Mid May to Mid June. Pre-grow about 25 days before transplanting, approximately between Mid April and Mid May. After a growing period of 45 days, harvest can begin around Late June and continues until Late October.
Sow and plant Squash
Planting 1: classic autumn squash
Planting 2: summer squash
Sow the seeds straight into a larger pot with potting compost. Don't prick them out — they can't handle root damage.
Plant at least two plants. The fruits only develop when pollinated by another plant.
Good and bad companions of Squash
Pumpkins need plenty of room and full sun, so put them at the edge of a bed where they can spread out. Pumpkin between loosely planted sweetcorn has proved itself, since the corn casts little shade. Add climbing beans on top, as in the three sisters from Central America, and it usually gets too dark for the pumpkin in our climate. Nasturtium, pot marigolds, borage and radishes count as good companions, and beans do too if they stand on the north side. Keep your distance from courgettes, cucumbers and melons, because they share mildew and viruses that aphids carry from plant to plant.
- Practical tip for this pair
- Supports pollination
- Shared pathogen, spreads through proximity
- Shared pathogen, spreads through proximity
- Shared pathogen, spreads through proximity
- Shared pathogen, spreads through proximity
- Competition for light, water, nutrients, root space
- Shared pathogen, spreads through proximity
Predecessors and successors of Squash
Pumpkins only return to the same bed after four years at the earliest, and the same goes for courgettes, cucumbers and melons. They share diseases that survive on plant debris in the soil. As a hungry feeder, the pumpkin does well in a bed that previously grew peas, beans or a green manure with clover. After the pumpkin, the bed is in good shape and almost free of weeds, because the large leaves shade the soil densely. Onions, garlic, leeks, carrots and parsnips benefit from that the following year, since they produce little foliage themselves. If you harvest the pumpkin early, you can still sow a green manure.
- Nitrogen release
- Nitrogen release
- Nitrogen release
- Nitrogen release
- Nitrogen release
- Nitrogen release
- Nitrogen release
- Nitrogen release
- Shared soil-borne pathogen
- Shared soil-borne pathogen
- Shared soil-borne pathogen
- Shared soil-borne pathogen
- Shared soil-borne pathogen
- Self-incompatibility
- Shared soil-borne pathogen
- Shared soil-borne pathogen
- Weed suppression for the next crop
- Weed suppression for the next crop
- Weed suppression for the next crop
- Weed suppression for the next crop
- Weed suppression for the next crop
- Weed suppression for the next crop
- Weed suppression for the next crop
- Shared soil-borne pathogen
- Shared soil-borne pathogen
- Shared soil-borne pathogen
- Shared soil-borne pathogen
- Shared soil-borne pathogen
- Self-incompatibility
- Shared soil-borne pathogen
Care and fertilising
These plants are heavy feeders. Prepare the soil with compost or well-rotted manure, and once fruits start forming, feed now and then with plant liquid feeds or brews.
Water generously, especially while the fruits are growing. Later, as they ripen, water only moderately so the squashes don't split.
Diseases and pests
On pumpkins you'll often see powdery mildew in summer, a white coating on the leaves that wipes off easily. It only becomes a problem if it turns up early in the year, otherwise the fruits still ripen. Downy mildew usually arrives in autumn, by which time the pumpkins are already ripe. Viruses are more of a nuisance, such as zucchini yellow mosaic, which leaves the foliage mottled and the fruits lumpy. Aphids carry them from plant to plant, so insect-proof netting up until flowering helps. Water at the base of the plants so the leaves dry off quickly, and protect young plants from slugs.
In wet weather, pumpkins and courgettes sometimes come down with gummy stem blight: the tissue at the base of the stem turns soft, a sticky sap oozes out, and small black dots appear. Cut out affected shoots straight away and always water at the base of the plant.
Harvest and processing
When squashes are ripe depends heavily on the variety. Squashes you want to store also need to be much riper than ones you plan to use straight away. Summer squashes you even harvest completely unripe. Ideally, let them cure for 1 to 2 weeks in a bright, dry spot at around 20 °C, with the resting point facing upwards. Watch out for bitter squashes. Never eat them! The bitter compounds are toxic and even in small amounts cause vomiting and diarrhoea, and can seriously damage the mucous membranes of the digestive tract.
Storage squashes must be fully mature. The skin should be so firm that you can't scratch it with your fingernail. The stem must be hard and dry, and you need to leave at least 3 cm of it attached to the fruit when harvesting.
Fruits can turn bitter if you've saved seeds from squashes that grew near ornamental gourds. Ornamental gourds often still contain high levels of these bitter compounds, which is why you must never eat them. If they grow too close together, the bitter traits cross back in.
For storage, choose a cool room at 12 °C to 18 °C and avoid stacking the squashes if possible.
Depending on the variety, they'll keep for 2 to 6 months — some butternut types even up to a year.
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