Cucumbers are a popular plant to grow as they can produce delicious fruits for weeks on end. Find out all you need to know about cucumbers, including where they originate from and how to propagate them.
Cucumbers (Cucumis sativus) are widely grown and for good reason, as nothing beats a cool and crisp home-grown cucumber on a hot summer’s day. Read on to learn about the origins of cucumbers, whether they are really a fruit or a vegetable, and how to propagate cucumber plants.
Cucumbers: origins and characteristics
Cucumbers are part of the Cucurbitaceae family of plants, which also includes melons (Cucumis melo) and squash (Cucurbita). These are thought to originate from Asia, or more specifically India, with its warm and humid climate. It was not until the Middle Ages that cucumbers were introduced to Europe.
Tender and with no frost tolerance, cucumbers are sun and heat-loving plants that can grow up to 4m in length, either vertically or along the ground. Often grown under cover here in the UK due to our varying summers, cucumbers can be grown vertically up trellises or frames to save space. They have tendrils which help them to hook onto frames. You can either grow cucumbers in pots or grow them directly in the soil. They produce large heart or triangular-shaped leaves and pretty yellow star-shaped flowers with five wrinkled petals.
Depending on the weather, cucumbers can flower and fruit from midsummer right up until the autumn and even earlier if grown undercover. With pollinator-friendly yellow flowers, older cucumber varieties tended to produce both male and female flowers for pollination. However, more recent cultivars have been bred to be parthenocarpic, which means they produce only female and self-pollinating flowers.
Cucumber fruits are typically long or short with a green skin and a pale core, although more exotic-looking varieties such as the round and yellow lemon cucumbers are also available. Interestingly, if left on the vine for too long, cucumbers continue to fully mature and turn from green to yellow-orange as their seeds ripen. Cucumbers mature rapidly at the height of the cucumber harvesting season. In the UK, they are classified as either outdoor (or ridge) varieties, or indoor varieties which tend to produce smaller fruits.
If left to fully ripen on the plant, cucumbers produce seeds which appear pale, flat, and elongated with a pointed tip. These seeds are easy to grow from, often producing fruits in as little as 8 to 12 weeks from sowing.
Are cucumbers vegetables or fruits?
If you are wondering if a cucumber is a vegetable or a fruit, you are not alone. Here in the UK, cucumbers are often thought of as vegetables. They are found in the vegetable section of a supermarket, have a low sugar content, and are generally used in savoury dishes. However, botanically speaking, cucumbers are classified as a fruit, as they produce seeds and berry fruits as a product of pollination.
Are cucumbers perennial?
Cucumbers are grown here in the UK as tender annuals and only have a short growing season. This is because they need to be kept above a minimum temperature of 12 ℃ and hence begin to dieback in the autumn, as the temperatures begin to drop. Cucumbers are not a perennial, as their natural lifespan lasts only one season, and the plant does not come back the following year.
Cucumber plant propagation
You can either propagate cucumbers from seed or cuttings. As cucumber seeds are so readily available to purchase, this is the most common option.
Germinating and growing cucumbers from seed is easy, and you can grow them indoors or outdoors. To collect seeds from a healthy existing cucumber plant, allow the cucumber to fully ripen on the vine and only harvest it once it has turned yellow and produced a hard skin. Once ready, cut the cucumber from the vine and leave it to dry out further if needed before extracting the seeds. Then place them in a glass of clean water for one to three days so their gel coating dissolves. After that, separate the seeds and leave them to dry before storing in an airtight container for future use. If stored correctly, cucumber seeds are viable for at least five years and will germinate reliably.
Cucumbers can also be grown from cuttings, which can be helpful if a cucumber plant stem breaks by accident. Although, with a short season, it is usually not worth propagating cucumbers this way as it can take a long time for the cuttings to grow roots and become productive.
Nevertheless, if you would like to grow cucumbers from cuttings, this is how to proceed. Take cucumber cuttings early in the morning when the plant is most hydrated and use a healthy parent plant. Using a clean and sharp pair of secateurs, take a cutting with two leaves present, just below a leaf node from a side shoot or growing tip. Place the cutting in a glass of water for 24 hours. Remove the lower foliage and apply a rooting powder to the bottom cut before placing in a pot pre-filled with a seed sowing compost mix. Place undercover in bright, but indirect light with a minimum temperature of 16 to 18°C and keep the soil moist. Cuttings can root in as little as two to three weeks, after which they can be grown on. However, they may take weeks to mature and fruit. You can only hope that they do so before the end of the growing season.
Tip: It is best to avoid collecting seed from any hybrid cultivars as any offspring produced are unlikely to come true. Also do not use seedless parthenocarpic types.
Cucumbers are hungry feeders. For a good harvest, you will need to fertilise them throughout the growing season. For more information, read our dedicated article on fertilising cucumbers.