Growing Cucumbers: Greenhouse Planting Guide


The best greenhouse for cucumbers is 15 ft. wide, with a 3-ft. gap between the staging and the roof. Ventilate the house with extreme caution, and close the ventilators quite early in the afternoon. About July a little extra ventilation may be given on the sheltered side to change the air in the house.

Never allow the atmosphere of the cucumber house to become dry, and maintain at all seasons a night temperature of 65° F. (18° C), which in the daytime may rise as high as 90° F. (32° C). Syringe the plants frequently, and damp down the walls and paths of the green- house, especially during the hot weather. Give the plants a feed of diluted liquid manure once a week.

When the sun becomes bright and scorching during the summer months, shade the greenhouse with a blind over the outside of the glass.


Cucumber seeds are sown in February or March in 3-in. pots, in a compost of three parts loam and one part peat. The bottom of the pot should be well crocked and filled to a depth of 1 in. with rough peat. Place one seed point downward 1 in. deep in the centre of each pot, cover, and water well. Place the pots on a shelf that has heating close below it.


After a fortnight the small plants should be planted out in their beds, but if these are not yet ready, or if the plants are ultimately to be planted out in the garden, repot the cucumbers in 5-in. pots, using a similar compost, but with twice as much peat. The cucumber is one of the few plants that should not be potted firmly. Insert each plant right up to the seed leaf, and again water well. Thereafter, water only when the soil appears dry, for the roots will not develop well in continually wet soil.

After a week the plants will need support; push into the soil a piece of fine bamboo 1-½ ft. long, and tie the stem to it loosely in order to allow for growth.


At least two weeks before planting out, make a bed 1-½ ft. wide at the base and l ft. wide at the top. Be sure that there is good drainage, for water must be able to escape quickly. Use any open-textured organic material for the base of the bed; baled straw makes a good border. Over the base lay 1 ft. of soil, followed by peat, which should always be kept slightly moist. A further 3 in. of sterilized soil may be placed over the peat. On the surface of the bed, build mounds of a good rich compost, three parts loam, one part peat. These should be moderately firm, about 2 ft. apart, and so arranged that drips from the rafters will fall between them. Warm the soil for a week before putting in the young plants.


At the end of May, when all fear of frosts is past, the young cucumbers may be planted out-of-doors. If they are to continue growing in the greenhouse, transfer them from their3-in. or 5-in. pots to their permanent bed when they are 6 in. tall. Immerse a pot in the middle of each mound to make a hole the size and shape of the ball of soil in the pot. Then knock the plant out of the pot and plant it firmly in the hole. The top of the plant ball should be slightly above the surface of the bed. Water well, giving 1 gal. to every three mounds, and provide a stake for training the new growth to the wires of the house.


Cucumbers should be trained up wires stretched the length of the greenhouse, 6 in. apart. Pinch back each plant when it reaches the fifth wire; this enables the lower fruit to swell more quickly. Do not allow any cucumbers to grow on the main stem. Stop the main laterals at the second leaf joint, and the sub-laterals at the first joint, keeping two fruit-bearing joints on each lateral. Remove all male flowers. Tie all growths to the wires loosely, to allow for growth. All fruit should hang well clear of ties and wires.


Soak the bed thoroughly twice a week with water of the same temperature as the greenhouse. If a water barrow is left in the greenhouse for 24 hours, the water will heat naturally.

It is essential to mulch cucumbers regularly with soil and peat mixed in equal parts. Leave the soil in the greenhouse for at least 12 hours before it is needed. Give the first top dressing about ten days after planting, and a second one as soon as the white root fibres appear on the surface of the soil. Use only a small quantity of mulch each time.


The following varieties are recommended for cultivation in the greenhouse: Butcher’s Disease Resister, a heavy cropper and popular because of its immunity from spot disease.

Excelsior Telegraph, a long, smooth variety that yields a heavy crop.

16. February 2012 by Dave Pinkney
Categories: Featured Articles, Garden Management, Gardening Calendar | Tags: , , , | Comments Off on Growing Cucumbers: Greenhouse Planting Guide


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