Squash
An ancient crop
Squash has been cultivated for a very long time. The first fruits were bitter. People only ate the oil-rich seeds. But the plant was refined and became an important staple food. In the 16th century, the plant arrived in Europe, where it was particularly welcomed by the Italians. In the 19th century, squash became widely popular in gardens and kitchens.
Summer squash and winter squash
Squashes belong to the same genus as pumpkins. In botanical Latin they are called ‘Curcubita’. Depending on how long the fruits can be stored, the plant is called summer squash (Curcubita pepo) or winter squash (Curcubita maxima).
Other names for summer squash are zucchini and courgette. Summer squash has a thin skin and is eaten fresh. It keeps for a couple of weeks in the refrigerator.
Winter squash has a thicker skin and harder flesh. It can be stored for several months. There’s something magical about being able to ‘harvest’ last year’s squash from the storage shelf for a warming February stew when the snow is swirling outside the window.
Direct sow or pre-grow squash
In southern Sweden, summer squash can be direct-seeded outdoors when the soil is at least 15 degrees. But the most common is to pre-grow squash. Sow indoors in late April or early May depending on the growing zone. Allow 4-6 weeks before planting out.
Feel free to soak the seeds before sowing to speed up germination. Sow 2-3 cm deep. Squash seeds need heat to germinate, about 25 degrees. Use an electric heating mat or place the seed on a radiator, underfloor heating or above a refrigerator. Keep moist during germination.
When the squash plants are emerging, put the pots in a bright spot. Replant in larger pots as they grow. When replanting, squash should not be placed deeper in the new pot. The root neck is sensitive to moisture.
Planting squash outdoors or in pots
Harden off the squash plants by leaving them outside for longer and longer periods over a few days. Cover them with fibre cloth if possible. Bring the pots inside for the night.
Squash thrives best in a warm, sunny and wind-protected position. Plant in well-fertilised soil with a distance of 50-80 cm between plants.
The indigenous people of North America used to co-cultivate the ‘three sisters’ – squash, corn and beans. It’s a smart farming technique. The nitrogen-fixing beans get climbing support from the corn, while the squash gets shade from the other two. Maybe something to try?
Squash can also be grown in pots. To get a good harvest, the pot should hold at least 20 litres of soil. If the pot is in a glassed-in area, it is often necessary to support pollination. Touch flower after flower with a brush as if it were a bumblebee flying around.
Caring for squash
Water regularly with fertiliser. Place grass clippings or other organic material between the plants. This will keep the moisture in the soil, smother the weeds and provide extra nutrition as they decompose.
Keep an eye out for slugs – especially when the fruits start to form.
Squash is sensitive to frost. Cover with fibre cloth if the nights are likely to be cold.
Harvesting squash
Harvest the fruits of summer squash as you go. The small fruits are soft with a thin skin. As they grow, both the skin and the flesh become a little harder. The more you pick, the more new fruits develop.
If a fruit starts to rot, fertilisation has not worked. Cut off the fruit to stimulate new fruit set.
Winter squash that are to be stored benefit from ripening properly on the plant. Handle the fruits carefully and store them in a dry and airy place. You can also pick small fruits of winter squash for fresh consumption.
Squash in cooking
Some ways to use the autumn harvest:
- Simmer squash in a delicious ratatouille.
- Cut squash into thin slices that are seasoned and dried into chips.
- Mix squash into bread baking for extra juicy loaves.
- Halve a courgette and scoop out the seeds. Put in a stuffing and gratinate.
- Roast in oven with olive oil, thyme and sea salt.
Author: Johanna Damm
Fact-checked by Erik Hoekstra
Last updated 2022-10-14