A well-grown specimen of a greenhouse (‘frame’) cucumber, straight and cylindrical, smooth-skinned and glistening, may reach 18in (45cm) or more in length. A thing of beauty, especially on the show bench, but also a thing which is difficult to grow. Cucumbers under glass need warmth and care plus regular watering and feeding, tying and stopping, protecting from pests and diseases, and so on. Ideally the humidity should be higher than that provided for tomatoes, but many people grow the two vegetables together under glass quite successfully. The temptation these days is to grow cucumbers outdoors as there is so much less work involved and varieties have improved. But if you want to pick fruits in May or June for early summer salads then growing under glass is the only answer.

Seed facts
Expected germination time: 3-5 days
Expected yield per plant: 25 cucumbers
Life expectancy of stored seed: 6 years.
Approximate time between sowing and cutting: 12 weeks
Ease of cultivation: Difficult – growing cucumbers under glass is time-consuming and costly.

Soil facts
· Usually only a few plants are grown – do not plant in border soil. Use J.I. Compost No. 3 in 10in (25cm) pots or buy growing bags.

Sowing and Planting
· Raise seedlings under glass – warmth (70-80°F (21-26°C)) is essential. Place a single seed edgeways ½ in (1cm) deep in seed compost in a 3in (7cm) peat pot. Sowing should take place in late February or early March for planting in a heated greenhouse or late April for an unheated greenhouse or frame. Keep compost moist – feed if necessary.
· Plant out in late March (heated greenhouse) or late May (unheated greenhouse) – 1 per pot, 2 per growing bag. Water in after planting.

Calendar
Sowing and planting time: as above
Cutting time: Usually mid June to the end of September; can extend from mid May to mid October.

Looking after the crop
· The temperature after germination must be maintained at a minimum of 60°F (15°C) (Ordinary varieties) or 70°F (21°C) (All-Female varieties).
· Keep the compost thoroughly moist but never waterlogged – little and often is the rule. Keep the air as moist and well ventilated as the other plants in the house will allow. Spray the floor (not the plants) to maintain a high humidity.
· Train the stem up a vertical wire or cane. Pinch out the growing point when this leader reaches the roof. The tip of each side shoot is pinched out at 2 leaves beyond a female flower. Female flowers have a miniature cucumber behind them – male flowers have just a thin stalk. Pinch out tips of flowerless side shoots when 2ft long.
· Remove all male flowers from Ordinary varieties – fertilized fruit is bitter.
· Feed every 2 weeks with a tomato fertilizer once the first fruits have started to swell.

Harvesting
· Cut (do not pull) when the fruit has reached a reasonable size and the sides are parallel. Cropping will cease if you allow cucumbers to mature and turn yellow on the plant.

Varieties
Ordinary varieties
These are the cucumbers for the exhibitor. They are the traditional cucumbers of the summer salad – long, straight, smooth and dark green.
Telegraph: An old variety, named when the telegraph was a new invention. Despite its age, Telegraph is still popular.
Butcher’s Disease Resisting: Another old favourite which is not as smooth-skinned as Telegraph but is reputed to be a heavy cropper.
Conqueror: An excellent choice for a cold greenhouse or frame – the fruits are long, smooth and high in flavour.
Sigmadew: Something different – an almost white cucumber noted for its flavour and thin skin.

All-Female varieties
These modern F1 hybrids have several advantages. As they bear only female flowers the tiresome job of removing male flowers is unnecessary. They are also much more resistant to disease and rather more prolific. There are two drawbacks – the fruits tend to be shorter than the Ordinary varieties and a higher temperature is required. If your house is unheated, choose an Ordinary variety.
Pepinex: The first of the females, formerly known as Femina. A good example of the group – high yields, lack of bitterness and no gummosis.
Topsy: Tops for flavour, according to the experts. Yields, however, are not very good and the seeds are not widely available.
Petita: The fruits are only about 8in (20cm) long but a large number are borne. Stands less than ideal conditions better than most All-Females, but often produces some male flowers.
Fembaby: A cucumber for the windowsill – small plants, small fruits and easy to train.
Uniflora D: The self-pruning cucumber. Side shoots grow about 6in (15cm) long and then stop – no more tying or pinching out.

Troubles
See Cucumber, outdoor