Cucumbers

01 About

The cucumber is one of the most rewarding crops you can grow with access to a greenhouse or a warm sheltered garden. Nothing from the supermarket compares to a freshly cut home-grown cucumber — crisp, fragrant, and tasting of summer. Modern all-female varieties have transformed cucumber growing in the UK, producing generous crops of smooth, long fruits without the need to remove male flowers. Outdoor ridge types are tougher and more compact, producing well in a sunny sheltered spot. With the right variety, consistent watering, and reasonable warmth, cucumbers will crop prolifically from midsummer through to September.

02 What to Grow

Cucumbers divide into two distinct groups and choosing the right one for your growing situation is the most important decision you make. Greenhouse (indoor) varieties produce long, smooth, near-seedless fruits and must remain under glass throughout the UK season — they lack the resilience to thrive outdoors. Outdoor ridge varieties are shorter, sometimes slightly knobbled, more tolerant of British summer conditions, and are the right choice for growing in a sunny sheltered border or large container. Within those groups, there are also mini and snacking types — compact, prolific, and ideal for pots, patios, and smaller gardens.

03 Varieties

The number of varieties shown for each crop is based on UK consumption data (2025/26) — the more popular the crop, the more variety choices we include.

🏠 Greenhouse / Indoor

All-female F1 varieties producing long, smooth, bitter-free fruits. Must be grown under glass in the UK. Remove any male flowers that appear to prevent bitterness.

Femdan F1

Greenhouse · All-female

Reliable, high-yielding all-female variety. Long smooth fruits to 35cm. Excellent disease resistance. One of the best-performing greenhouse cucumbers for UK growers.

• F1
• Greenhouse
• All-female
• Beginners

Telegraph Improved

Greenhouse · Heritage

The classic British greenhouse cucumber. Long, straight, dark green fruits with excellent flavour. An open-pollinated heritage variety — thin-skinned and prolific.

• Greenhouse
• Heritage
• ⭐ Flavour

Carmen F1

Greenhouse · All-female

Outstanding all-female variety. Long, dark green fruits with crisp white flesh and superb flavour. Heavy crops over a long season. Widely regarded as one of the finest UK greenhouse cucumbers.

• AGM
• F1
• Greenhouse
• All-female
• ⭐ Flavour

🌿 Outdoor / Ridge

Tougher, more compact varieties bred for outdoor growing in a warm sheltered spot. Produce shorter, sometimes ribbed or knobbled fruits with excellent flavour — often better than indoor types for eating fresh.

Marketmore

Outdoor · Ridge

The most reliable outdoor cucumber for UK gardens. Medium-length, dark green, slightly ribbed fruits with firm crisp flesh. Very heavy yields in a warm spot.

• AGM
• Outdoor
• Beginners
• ⭐ Flavour

Burpless Tasty Green

Outdoor · Ridge

Thin-skinned, virtually seedless fruits with no bitterness. Long and straight for a ridge type. One of the finest outdoor cucumbers for fresh eating.

• Outdoor
• ⭐ Flavour

Crystal Lemon

Outdoor · Ridge

Distinctively round, pale yellow fruits the size of a lemon. Mild, crisp, sweet flesh with no bitterness. Prolific and unusual — a real talking point in the garden and on the plate.

• Outdoor
• Heritage
• ⭐ Flavour

🥒 Mini / Snacking

Compact, prolific varieties producing small fruits 10–15cm long, ideal for eating whole. Well suited to containers, grow bags, and smaller gardens.

Mini Munch F1

Mini · Outdoor

Extremely prolific little cucumber producing clusters of stubby, dark green fruits. Crisp, sweet, no bitterness. Can be grown outdoors or in a greenhouse. Excellent for children and snacking.

• AGM
• F1
• Outdoor
• Greenhouse
• Container
• Beginners

Iznik F1

Mini · Outdoor

A compact Turkish variety producing masses of smooth, thin-skinned fruits 12–15cm long. Good flavour and very productive outdoors. Well suited to UK conditions.

• F1
• Outdoor
• Container
• ⭐ Flavour

Cucino F1

Mini · Patio

Bred specifically for patio and container growing. Compact bushy plants producing generous quantities of smooth 12–15cm fruits. Good flavour, thin skin. Reliable outdoors.

• AGM
• F1
• Container
• Patio
• Beginners

04 Where to Source

Cucumber seeds, plug plants, and young plants are available through several routes. Specialist seed companies offer the widest range of greenhouse, outdoor, and mini varieties — including heritage types unavailable in garden centres.

📬 Seeds by Post

Online specialist seed companies offer the widest variety selection, including heritage types and the latest all-female F1 greenhouse varieties. Order from January — popular varieties like Carmen and Femdan sell out early. Read packet information carefully and note whether a variety is suited to greenhouse or outdoor growing.

🏪 Garden Centres

Most garden centres stock a reliable range of cucumber seeds from February and plug plants or young plants from April. Selection is narrower than online but quality is inspectable and staff advice is available. Look for plants with short internodal length — compact, stocky plants establish far better than tall, leggy ones.

🛒 Markets & Plant Sales

Farmers markets, community plant sales, and local garden shows are an excellent source of locally-grown cucumber plug plants in May and June. Many specialist growers sell named varieties at competitive prices. A well-grown locally-produced plant in late May is often better than an early purchase from a garden centre.

05 Planting Options

🏠 Greenhouse

A greenhouse is the gold standard for indoor cucumber varieties. Greenhouse cucumbers need consistent warmth — minimum 16°C at night, ideally 20–25°C during the day. Plant into grow bags (2 per bag) or large containers of at least 30cm diameter. Train the main stem vertically up a wire or cane, tying in every 25–30cm. Pinch out the growing tip when it reaches the top of its support. For all-female varieties, remove any male flowers (those without a tiny cucumber behind the petals) immediately — a single male flower pollinating females causes bitter, seedy fruits.

Suitable varieties: Femdan F1, Telegraph Improved, Carmen F1. All-female varieties strongly recommended for greenhouse growing.

🛍️ Grow Bags

Grow bags are the classic British method for greenhouse cucumbers. Use one bag for 2 plants — do not overcrowd. Knead the bag thoroughly before cutting planting holes. Use watering rings inserted into the planting holes — without them water runs off the surface without reaching roots. Grow bag compost runs low in nutrients after 4–6 weeks; begin a high-potash liquid feed every 7–10 days once cucumbers start to form.

Suitable varieties: All varieties. Two plants per standard 40-litre bag. Indoor varieties in greenhouse; ridge varieties outdoors in a sheltered spot.

🌍 Outside in Ground

Outdoor ridge cucumbers perform excellently in a warm, sheltered, south-facing position in a good UK summer. Dig in plenty of well-rotted manure or garden compost before planting. Harden off plants grown indoors for 10–14 days before planting out, and do not plant until after the last frost — usually late May to early June. A warm south-facing wall or fence significantly improves results. Pinch out the growing tip after 6–8 leaves to encourage bushy, branching growth. Water consistently at the base and feed weekly once fruits begin to form.

Suitable varieties: Marketmore, Burpless Tasty Green, Crystal Lemon, Mini Munch F1, Iznik F1, Cucino F1. Do not grow greenhouse varieties outdoors.

06 Companion Planting

✅ Grow nearby

• 

  🌸 Nasturtiums

  Trap crop that draws aphids and blackfly away from cucumbers. Nasturtiums also attract beneficial insects including hoverflies and ground beetles.

• 

  🌿 Basil

  Thought to repel aphids and whitefly when grown near cucumbers. Basil and cucumbers share similar growing requirements — warmth, water, and shelter.

• 

  🔴 Radish

  Quick-growing radishes can be interplanted as a catch crop between cucumber plants, making use of space while cucumbers establish. May deter cucumber beetle.

❌ Keep apart

• 🥔 Potatoes — Both susceptible to similar soil-borne diseases. Keep apart and rotate each year.
• 🌿 Fennel — Fennel root compounds inhibit growth of nearby vegetables.
• 🌿 Sage — Aromatic herbs with strong oils are thought to inhibit cucumber growth when planted in close proximity.
• 🎃 Squash & Pumpkins — Close relatives that compete strongly for nutrients and water, and will cross-pollinate if you are saving seed.

07 Sowing — How To

Cucumbers need warmth to germinate — a minimum of 18°C, ideally 21–24°C. Sow in individual 9cm pots rather than open trays; cucumbers resent root disturbance. Sow seeds on their side or edge — this reduces the risk of the seed tip rotting before germination. Sow from mid-March to late April indoors. Germination is rapid at the correct temperature — usually 3–5 days.

1. 

   Fill pots

   Fill individual 9cm pots to within 1cm of the rim with moist seed compost. Firm gently. One pot per seed.

2. 

   Sow seeds

   Push one seed per pot, sowing on its side or edge, approximately 1cm deep. Sideways sowing prevents the seed tip from sitting in moisture and rotting before germination.

3. 

   Cover lightly

   Cover with 1cm of fine compost or vermiculite. Firm gently. Vermiculite is preferable — it retains moisture without compacting or forming a crust.

4. 

   Label clearly

   Label each pot with the variety name and sowing date. If growing more than one variety — especially a mix of indoor and outdoor types — clear labelling is essential.

5. 

   Water gently

   Water with a fine rose. The compost should be evenly moist but not waterlogged. Soggy compost at this stage causes rot before germination.

6. 

   Cover and warm

   Place a propagator lid or cling film over the pots. Position in a warm spot — 21–24°C is ideal. Check daily. Germination should occur within 3–5 days at the correct temperature.

7. 

   Move to light

   Remove the cover the moment seedlings emerge and move immediately to the brightest available windowsill. Cucumbers in low light become leggy and weak within days of germination.

8. 

   Ventilate

   Keep the lid off once seedlings are up. Good airflow prevents damping off, which can wipe out cucumber seedlings rapidly in warm, humid conditions.

Regional sowing timing

Region	Sow / plant	Harvest	Notes
Scotland & Far North	Mar–Apr	Jun–Sep	Heated propagator essential; sow April for late May greenhouse planting · Early to mid-April
Northern England	Mar–Apr	Jun–Sep	Propagator strongly recommended; windowsill viable from late March · Late March to mid-April
Midlands & Wales	Mar–Apr	May–Sep	Good results from heated propagator from mid-March · Mid-March to early April
Ireland & Isle of Man	Mar–Apr	May–Sep	Good results from heated propagator from mid-March · Mid-March to early April
South & SE England	Mar	May–Sep	Earliest reliable start; greenhouse growers can sow mid-March · Mid-March to early April
South Coast & SW	Mar	May–Sep	Most favourable UK region; greenhouse planting possible late April · Mid-March to late March

08 Using a Propagator

Cucumbers need genuine warmth to germinate reliably — 21–24°C is the sweet spot. A heated propagator is by far the most reliable way to provide this in a UK home. Unheated propagators placed on a warm windowsill can work from April, but germination is slower and less consistent.

Heated propagator

Provides consistent bottom heat regardless of room temperature. Set to 21–24°C for cucumbers. Germination in 3–5 days. Remove the lid the moment seedlings appear — cucumbers are very susceptible to damping off in warm, humid conditions.

Standard unheated propagator — A lidded seed tray traps warmth and humidity around germinating seeds without electricity. Performance depends entirely on room temperature — best placed on a warm windowsill and used from March onwards. Replace the lid promptly after watering. Remove it completely the moment seedlings emerge to prevent damping off.

09 Soil Requirements

pH

6.0–7.0

Best

Sandy loam, Loam

Tolerates

Clay loam

Avoid

Waterlogged, Compacted clay

10 Ongoing Care

💧 Watering

Keep cucumbers consistently moist — they have a very high water requirement, especially in a greenhouse. Erratic watering causes bitter fruits and root problems. Water at the base and avoid wetting foliage, which encourages mildew. Daily watering may be needed in summer heat.

🌿 Feeding

Once the first fruits develop, feed weekly with a balanced liquid fertiliser, switching to a high-potash feed as fruiting peaks. Cucumbers are hungry crops — feeding every week sustains yield and fruit quality throughout the season.

🎋 Training & Pinching

Train the main stem up a vertical cane or string. Pinch out the growing tip when it reaches the top of the support. Pinch out sideshoots of indoor cucumbers to 2 leaves beyond each fruit. Remove all male flowers on all-female varieties to prevent bitter fruits.

🥒 Harvesting

Harvest cucumbers before they yellow — pick when deep green and firm. Regular picking encourages continued production. Cut cleanly with a knife rather than pulling, which can damage the stem. Outdoor varieties can be left slightly longer than indoor types.

11 Watch Out For

🐛 Insects & pests

• 🐜 Aphids (Blackfly & Greenfly) — Curled, distorted, or stunted growing tips — aphids inject saliva that causes leaf curl to protect them
• 🕷 Spider Mite — Fine, silky webbing on the underside of leaves and between growing tips — the definitive identification sign
• 🐌 Slugs & Snails — Silver slime trails on leaves, soil, and pots — often the first sign before damage is found
• 🤍 Mealybug — White, fluffy or mealy patches in leaf axils, stem joints, and under leaves — the insects themselves

🍄 Diseases to watch

• ⬜ Powdery Mildew — Powdery mildew is caused by a range of related fungi, each specific to its host plant — courgette mildew cannot infect peas, and vice versa. The characteristic white powdery coating on leaf surfaces appears in warm, dry conditions (unlike downy mildew which prefers cool and wet). Rarely kills plants but severely reduces yield and plant vigour.
• 🔵 Downy Mildew — Downy mildew is caused by oomycetes (water moulds) and is completely unrelated to powdery mildew despite the similar name. It thrives in cool, wet, humid conditions and is most damaging in spring and autumn. Each host plant has its own specific downy mildew species. Lettuce downy mildew can destroy an entire bed within days in the right conditions.
• 🌿 Mosaic Virus (TMV / CMV) — Tobacco mosaic virus (TMV) and Cucumber mosaic virus (CMV) are among the most widespread plant viruses affecting vegetable crops worldwide. TMV is extraordinarily stable — it can remain viable on contaminated hands and tools for years, and even survives in processed tobacco. There is no cure; infected plants must be destroyed.
• 🩶 Botrytis (Grey Mould) — Botrytis cinerea (grey mould) is the most ubiquitous fungal pathogen in temperate gardens — present in virtually every garden soil and on plant debris. It becomes a disease only when conditions favour it: cool, humid, poorly ventilated environments with damaged or senescent plant tissue. In a greenhouse in autumn it can destroy an entire tomato or grape crop.

Full identification and treatment advice is in the Pests and Diseases sections.

12 Storage & Preserving

🥒 Fresh Storage

Cucumbers are best eaten on the day of harvest. Store unwashed in the salad drawer of the fridge for up to 4–5 days. Once cut, wrap the cut end tightly in cling film and refrigerate — exposed flesh dries and deteriorates rapidly. Do not store near apples or bananas — ethylene gas accelerates yellowing. Home-grown cucumbers kept at room temperature keep for no more than 1–2 days.

🥗 Cucumber Pickle

Pickling is a classic way to use a cucumber glut. Pickled cucumbers are excellent alongside cold meats, in sandwiches, or as part of a salad board. Follow a tested recipe.

🫙 Tzatziki & Recipes

Tzatziki is the simplest and most satisfying use for a freshly harvested cucumber. Grate the cucumber, salt and squeeze out as much moisture as possible — this step is non-negotiable or the result is watery. Combine with thick Greek yoghurt, crushed garlic, fresh dill, a squeeze of lemon, and good olive oil. Refrigerate for at least an hour before serving. Keeps for 3–4 days covered in the fridge.

🧊 Dealing with a Glut

Cucumbers do not freeze well raw — the high water content turns to ice crystals, leaving a mushy texture on thawing. Best strategies for a genuine glut: give surplus to neighbours; make a large batch of quick pickles; use excess in cold soups such as chilled cucumber soup with mint and yoghurt; or make cucumber jam — an underrated preserve with a clean, light flavour. Plan your sowing to stagger the harvest over several weeks.

13 Expert Tips

14 Common Mistakes

15 See Also

• 🌼 Companion Planting
• 🔄 Crop Rotation
• 🛍️ Standard Grow Bag