When to plant Cucumbers in Cardiff

Cucumis sativus

Cucumber
Cucumber · Cucumis sativus

A tender climbing vine grown for its crisp fruits, requiring warm conditions and consistent moisture. In the UK, greenhouse varieties yield earlier and longer, while outdoor ridge types are hardier but need a warm summer.

200 cm · Full Sun · High Water

Calibrated to Cardiff · average last frost around 22 Apr

Sow indoors May, plant out June, harvest August to October. Typical frost risk October to April.
ActivityJanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember
Sow indoorsNoNoNoNoYesNoNoNoNoNoNoNo
Plant outNoNoNoNoNoYesNoNoNoNoNoNo
HarvestNoNoNoNoNoNoNoYesYesYesNoNo

Growing guide

What to do through the growing season

Change the guide to see different planting timelines and tips.

Sow an outdoor variety indoors, harden it off, then plant into a warm, sheltered bed.

  1. 01

    Sow Seeds Indoors

    6 May to 13 May

    Sow seeds on their edge to a depth of in modules from 6th May - 13th May. Keep them at on a warm windowsill or in a propagator. Sow no earlier than this to avoid leggy, root-bound seedlings.

  2. 02

    Harden Off Seedlings

    20 May to 3 Jun

    Gradually acclimatise seedlings to outdoor conditions over 15 days from 20th May - 3rd June. Place them outside in a sheltered spot during the day, bringing them in at night. This toughens them up before transplanting.

  3. 03

    Transplant Outdoors

    3 Jun to 17 Jun

    Plant into a warm, sunny bed around 3rd June - 17th June, but wait until local temperatures stay above . Space plants apart, water them in and protect them if a cold spell returns.

  4. 04

    Let Plants Sprawl

    10 Jun to 1 Jul Dates as each sowing reaches this stage

    Allow plants to spread naturally across the ground or over a low frame. Do not pinch out flowers, as outdoor varieties need bee pollination to set fruit. Mulch around plants to suppress weeds and retain moisture.

  5. 05

    Water and Feed Regularly

    3 Jun to 28 Oct Dates as each sowing reaches this stage Optional · repeat every 2 weeks

    Keep the soil moist from 3rd June, watering at the base in dry weather. Feed container plants every 14 days once flowering starts, switching to a high-potassium liquid fertiliser.

  6. 06

    Harvest Cucumbers

    2 Aug to 28 Oct Dates as each sowing reaches this stage

    Pick fruits regularly when they reach a usable size from 2nd August - 28th October. Cut them from the vine with a knife, harvesting every few days to encourage continuous production. Outdoor varieties may have a shorter season, so pick promptly.

Suggested varieties

Popular varieties of Cucumber to consider

Marketmore

A reliable outdoor ridge cucumber with good disease resistance, producing dark green fruits ideal for slicing.

Carmen

A popular greenhouse variety that is parthenocarpic, yielding long, smooth fruits without pollination.

Crystal Apple

An heirloom outdoor type with round, pale yellow fruits and a mild flavour, suitable for cooler summers.

Cucumber guides by town

See how Cucumber timing shifts in other towns with different frost dates.