Undercover: May 2012

Don’t be put off by the thought of dealing with live bugs – biological controls are straightforward to put in place and completely safe to you, your pets and plants. They can seem expensive, but the beneficial creatures work hard over many weeks – sometimes for the whole season – and you can leave them unaided to keep up the battle, even when you are away on holiday

Plant tender crops

In most regions it should be warm enough to plant out all tender crops in greenhouse and polytunnel borders or their final containers, but be prepared to give the most vulnerable ones extra heat or protection in cold spells (aubergines and greenhouse cucumbers, for example).

Cucumbers need careful planting. Make sure the top of the rootball (the compost in the pot) sits at the same level as the soil surface, and on heavy ground draw the soil away to leave the plant on a slight mound so water drains away. Water the plants to settle them in, but then leave them for a few days – over-wet roots are a killer for young plants.

Tomatoes, peppers and aubergines are less fussy about planting depth – in fact, deep planting (up to the first set of leaves) is sometimes recommended for tall spindly tomatoes; they should make extra roots along the buried stem. However, if you have grafted plants, take care not to cover any of the stem otherwise unwanted shoots could grow from the rootstock.

Plant now: Tomatoes, French beans, courgettes, sweetcorn, peppers, cucumbers, aubergines, sweet potatoes

May sowings
Cucumbers and melons should grow quickly in the warmth if sown this month – you may find they catch up with earlier crops and are less prone to root and stem rots. If you have space, why not experiment with some more exotic cucurbits, too? Seed is becoming much easier to find – you could try Mexican gherkins from Suttons (www.suttons.co.uk), achocha from Real Seeds (www.realseeds.co.uk) or luffa
from Chilterns (www.chilternseeds.co.uk),
for example.

Sow now: Cucumbers, melons, and other cucurbits; basil, coriander, leafy amaranths

Beating the hungry gap
Although crops outside are still sparse, early spring sowings undercover should now be rewarding you with a welcome harvest – luscious hearted lettuce, tender kohl rabi, sweet sugar peas and the first delicious new potatoes, for example.

Harvest now: Salad leaves, hearted lettuce, sugar peas, broad beans, kohl rabi, spinach, cabbage, carrots, onions, spring onions, new potatoes, baby courgettes, strawberries.

Deshoot tomatoes

Remove sideshoots from the leaf axils of cordon tomatoes as you plant them, and regularly, from now on. The plant will then concentrate its energies into more productive growth.

No such pinching out is necessary with bush varieties.

Watch the watering

May can be a deceptive month for watering. In warm sunny spells, newly-planted crops will need regular watering until they have made new roots into the soil. However, don’t overdo it if the weather turns cooler, especially for plants in containers which can easily become waterlogged. If in doubt, push your finger a few inches into the soil or compost to the side of the rootball to check how moist it is.

Prune and train vines

Start pruning vines as soon as they come into leaf, otherwise they can easily take over a greenhouse or tunnel. Select vigorous flower-bearing sideshoots – one from each spur on the main stem – and secure them to cross wires or other framework. Then remove all other new growth. This will prevent a jungle and give you healthier, larger grapes.

• Read the full article in Kitchen Garden magazine, May 2012!