Propagate Cucumbers From Seed: It’s Best To Start Them Between February And April
Elizabeth is a Permaculture Garden Designer, Sustainability Consultant and Professional Writer, working as an advocate for positive change. She graduated from the University of St. Andrews with an MA in English and Philosophy and obtained a Diploma in Applied Permaculture Design from the Permaculture Association.
Reviewed By COLIN SKELLY
Colin is a Horticulturist and Horticultural Consultant with experience in a range of practical and managerial roles across heritage, commercial and public horticulture. He holds the Royal Horticultural Society’s Master of Horticulture award and has a particular interest in horticultural ecology and naturalistic planting for habitat and climate resilience.
Contributions From EMILY CUPIT
Emily is a Gardening Writer, Photographer and Videographer from Derbyshire, UK. She is the Founder of Emily's Green Diary - a community of more than 75,000 people who share in her gardening journey.
IN THIS GUIDE
Cucumbers taste amazing when you have grown them yourself at home and doing so is well worth the effort.
Even a single plant, when properly placed and cared for, can be amazingly productive, often giving you more cucumbers than you can eat over the summer months.
Fortunately, growing your own cucumbers is not hugely challenging.
Although you can purchase young plants rather than propagating your own, it is relatively easy to grow your own cucumber from seed, as well as being an eco-friendly and sustainable choice.
Cucumbers are typically sown indoors between mid-February and late April or, with some varieties suited to outside cultivation, in late May or early June.
To grow cucumbers from seed:
- Choose and source your cucumber seeds.
- Decide where to sow and grow your cucumbers.
- Sow seeds either indoors or directly where they are to grow.
- Pot up cucumber seedlings as required or plant out indoor-sown cucumbers outdoors in early June.
| Difficulty | Easy |
| Equipment Required | Pots or seed discs, seed-starting compost, cucumber seeds |
| When To Sow | February to April (indoors), May to June (outdoors) |
When To Sow Cucumber Seeds
Cucumber seeds should usually be sown indoors or undercover in a heated propagator.
When precisely you sow indoors will depend on where you decide to grow your crop.
If you plan to grow your cucumbers in a heated greenhouse, then you should sow between mid-February and mid-March.
If you are growing your cucumbers in an unheated greenhouse or polytunnel, sow them sometime in April.
If you plan on growing suitable cucumber varieties outdoors then it is also best to sow in late April.
1) Acquire Your Seeds
If you want to grow cucumbers from seed then one of the first decisions that you will have to make is which particular cucumber varieties you will grow.
Remember, there are many different varieties to choose from.
Some are best suited to growing in a greenhouse or polytunnel, while others are suited to outdoor cultivation.
It is important to make sure that you choose the right variety or varieties for you and your intended growing location.
2) Choose A Suitable Spot
Remember, you can grow cucumbers in a heated greenhouse space, in an unheated greenhouse or polytunnel, or outdoors in your garden.
It is important to make this decision before you start sowing because, as mentioned above, it will dictate the timing for sowing the seeds.
You will also need to decide whether you will sow your seeds indoors or directly outside where they are to grow.
If you are growing outside, then you might still sow indoors or you might sometimes direct sow if you live in a milder area.
However, sowing indoors is generally the best policy for most of us in the British Isles.
3) Sow Cucumber Seeds
Cucumber seeds that you decide to sow indoors should be sown 1-2cm deep in small pots or in the ground if directly sowing.
The seeds should be sown on their side.
Make sure that you keep the seeds in moist seed-starting compost and at temperatures of 21°C for successful germination.
Although a sunny windowsill will often do, a heated propagator can increase your chances of success.
4) Pot Up Or Plant Out
If you have sown indoors, then you should pot up your cucumber seedlings into pots at least 25cm in diameter that are filled with good quality, peat-free potting compost.
Typically, you will do this in late March if growing in a heated greenhouse or in late May in an unheated undercover growing area.
Alternatively, you can plant cucumbers into the ground or raised beds either under cover or outdoors.
Undercover, you may plant out into the greenhouse or polytunnel beds or borders in May or early June.
Outside, you will typically wait until early June and may see better results if you first warm the soil with row covers or cloches.
“Given the need to delay sowing due to the need for soil temperatures to increase, sowing indoors, even on a windowsill, will produce more reliable germination than growing outside,” shares Master Horticulturist Colin Skelly.
“They will also be far less prone to suffering damage at an early stage of growth due to slugs and snails.”
Wherever you choose to sow and grow your cucumbers, take good care of your plants and you will surely be rewarded with a bounty of cucumbers for your salads throughout summer and often well into autumn.
