Cool and crunchy cucumbers, fresh from the garden, are in a league of their own. Cucumbers grown in the greenhouse require slightly different care than those grown outdoors. In this short video, we show you how to grow both outdoor and greenhouse varieties—and share our nifty idea for making a fantastic cucumber frame to grow them up for easy picking.
There are different cucumber varieties for growing outdoors and for growing in a greenhouse. Outdoor cucumbers can tolerate cooler climates, and often have rough or spiny skins. Greenhouse cucumbers produce smoother fruits but need extra warmth and protection for success. Some varieties will happily grow indoors or outdoors
Sow cucumbers from mid spring into small pots of seed starting or general-purpose potting mix. Cucumbers need temperatures of at least 68ºF to germinate, so either place pots in a propagator, or wait until late spring to get started.
Sow two seeds an inch deep in each pot, then water well. Once the seedlings emerge, remove the weakest to leave one per pot.
Growing Greenhouse Cucumbers
Greenhouse cucumbers can be planted into beds, containers, or growing bags. Train your cucumbers up supports such as bamboo canes, vertical wires, strong netting or trellis. Pinch out the growing tips when the plant reaches the top of the support to encourage it to produce side shoots. Pinch out the tips of side shoots so that just two leaves remain beyond each developing fruit.
Keep plants well watered, and feed every two weeks with a liquid fertilizer that is high in potassium.
Remove all male flowers from greenhouse cucumbers (unless you’re growing an all-female variety). This prevents bitter-tasting fruits. Female flowers have a slight swelling behind each bloom that will become a fruit if pollinated.
Growing Outdoor Cucumbers
Outdoor cucumbers should be transplanted in late spring or early summer, once the soil has warmed up. Gradually acclimatize (‘harden off’) plants to outdoor conditions for a week or two beforehand – a cold frame is useful for this. In warmer climates you can sow seeds directly into their final growing positions.
Cucumbers need a fertile soil to grow well. Dig in plenty of rich, well-rotted organic matter such as compost before planting. If you’re growing your cucumbers vertically on supports, set plants 18 inches apart. If you’ll be allowing them to sprawl over the soil surface instead, plant them no less than three feet apart.
Pinch out the growing tips after six leaves have formed. This will encourage plants to produce fruiting side shoots. Climbing cucumbers may need to be tied in to their supports, especially once the fruits start to develop.
Making a Cucumber Frame
A cucumber frame is a great way to support outdoor cucumbers. Stretch chicken wire or netting over a wooden frame and secure it into place with staples or U-shaped nails. Lean the frame against an A-frame made of sturdy bamboo canes.
Salad leaves such as lettuce can then be grown in the shade of the frame – a clever solution for growing cool season crops in hotter areas.
Also, see our video on how how to build a trellis and support for cucumbers.
How to Harvest Cucumbers
Harvest cucumbers regularly to encourage more fruits using a sharp knife or pruners. Harvest while they’re still small. Gherkin varieties are picked very small – an inch long for crunchy cornichons or three inches long for larger pickles.
See more tips on the Almanac’s Cucumber Growing Guide.
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