AS COOL AS CUCUMBERS

Give them enough heat and moisture and they’ll reward you with refreshing fruit galore, says Monty Don – but beware of pests...

This has been a good year for cucumbers and gherkins (essentially a warty-skinned, small cucumber ideally suited to pickling) – but then most years are for me. I claim no expertise or special skill because cucumbers are reliably easy to grow as long as you give them the conditions they love, and that almost invariably means a greenhouse.

I have successfully grown ‘ridge’ types outside, which are much hardier and have tougher, rougher skins, but as a rule all cucumbers need warmth and wet to thrive. While this part of the world is good at being wet, the warmth is nearly always insufficient – and if we do have a really hot summer it is nearly always dry, which is not ideal either. So I cram my cucumbers into the far end of my greenhouse, and although there is not enough space, they love the hot, damp conditions and reward me with dozens of fruits.

I sow the seed in three-inch pots in late April and put them on a heated bench to germinate – a windowsill above a radiator is fine. I let them reach about six inches tall (big enough to have a decent root system but not so big that they are flopping about) before potting them into their final container, which should be as large as you have space for because they are big, greedy plants. I half-fill the pot with neat garden compost before adding a peat-free potting compost which helps feed them as well as acting as a sponge to hold plenty of moisture.

I construct a bamboo tripod in the pot for them to clamber up, then tie them in regularly until they are established. I water them really well daily without fail and give them a liquid seaweed feed every week. This is the secret to good cucumbers – heat, food and drink, and plenty of it. If planted outside, it is best to dig pits or a trench and add lots of compost.

Pick the fruit often, as this will stimulate more fruit. It is also easier to cope with a few small ones at a time rather than a glut of whoppers. We make tzatziki, cucumber soup and, most deliciously of all, fried cucumbers served hot with a cream sauce. A large fruit can be cut in half while still on the vine and the cut will callus over so the rest can be harvested later.

To encourage straight growth they need to

hang cleanly. Train them up canes set at an angle, such as a wigwam or in cordons at 45°. The fruit will then hang vertically, unimpeded by surrounding growth.

It is likely that the Romans introduced cucumbers to Britain, although they originate from the Himalayas. Until Victorian times they were commonly called ‘cowcumbers’ and were often regarded with suspicion. This is because traditionally they produced male and female flowers. If the male flowers pollinated the female ones, the resulting fruits were bitter, so the male ones had to be pinched off on a daily basis. Today most varieties have all-female flowers. However, if stressed, particularly by cold, the plants may still produce male flowers; these must be removed to avoid bitter fruits.

Cucumbers grown indoors are susceptible to red spider mite, cucumber mosaic virus and powdery mildew. Red spider mite tends to build up when it is very dry, and damping the floor down and watering regularly should eliminate this. Good ventilation is the best prevention for powdery mildew. Cucumber mosaic virus is carried by aphids and will manifest itself in yellow and stunted leaves.

Monty harvesting his cucumbers