Pests & Dideases

Vegetables

Sow direct in ground.

Dwarf French bean, runner bean, beetroot, calabrese, early carrot, summer cauliflower, lettuce, spring onion, pea, mangetout pea, radish, spinach / leaf beet, swede, turnip

Sow in Pots

Sprouting broccoli, autumn cabbage, winter cabbage, calabrese, autumn cauliflower, winter cauliflower, courgette, kale, marrow, pumpkin, sweet corn.

Brassicas can be sown in a seed bed.

Plant outdoors

Dwarf French bean, runner bean, brussels sprouts, summer cabbage, calabrese, summer cauliflower, autumn cauliflower, self blanching celery, courgette, leek, marrow, onion from seed, main crop potatoes, shallot, pumpkin, sweet corn, outdoor tomato.

Fruit

Hoe off or pull out raspberry suckers appearing between rows. Very vigorous plants may also need some selective cane removal, so that there will be sufficient air and light penetration between the branches, and to ensure the 
plant has enough energy to ripen all the young fruits.

Net soft fruits as they begin to ripen.

Plant out seedlings of alpine strawberries.

Remove strawberry runners before they start to creep along the ground. Leaving them will only sap energy from existing plants, so reducing their yield of fruit. If you need runners in order to have new plants for next year, then pinch 
off the flowers from a couple of selected plants, encouraging them to produce green shoots and runners (rather than fruits and flowers), which you can save and pot up separately.
Any early strawberry crops that were kept under glass or under fleece and cloches, should now be uncovered  to allow access for pollinating insects.

Control weeds to prevent them competing for moisture and nutrients. Hoe regularly between rows on hot days to make sure the weeds dry up and die.

Over-vigorous apple and pear trees can be ring-barked. Heavy crops of blossom can also be thinned, to reduce the numbers of fruits that form with the aim of encouraging more even ripening, better fruit quality, and reduce problems with biennial bearing.

Gooseberry blossom may also be thinned in order to produce a smaller number of large dessert fruits.

Stay alert for gooseberry sawfly damage and the raised red blisters of currant blister aphid.

Do not be overly worried if the leaves on your pear tree start to come up in small pale blisters. This is probably due to the pear leaf blister mite. The damage is not as severe as the plant's appearance may suggest. Infested trees can still produce a good crop of pears.

Reduce numbers of rotten strawberries by tucking straw mulch, strawberry matting or similar around the plants, to prevent the fruits from touching the soil or getting too damp. Covering the whole bed with netting will also reduce bird 
damage.

Apples and pears may need spraying against scab, where this has got out of hand in previous years.

Keep watch for signs of cane spot or spur blight on blackberries and hybrid berries. Ensure that any fungicides used have approval for use on edible crops. 

Blackcurrants are vulnerable to big bud mite (affected buds appear larger than normal). The mites can spread blackcurrant reversion virus. Virus symptoms will be evident once the plant comes into flower, as the flowers look red rather than grey. Affected plants must be dug up and disposed of in the rubbish, or by burning. Grow resistant varieties such as ‘Farleigh’, ‘Foxendown’ or ‘Ben Hope’. 

Herbs

Continual supplies of basil, coriander and parsley can be had by sowing a little seed of each every fortnight.
Sow borage and nasturtium seed for their edible flowers.
Lift and divide herbs (such as mint and lemon balm) that have outgrown their allotted space. Make sure to remove all stray roots, as they can easily become invasive.
Control weeds by hoeing. Weed infested clumps may need lifting to disentangle weeds from the plant roots.

Around the Garden

Harvest spring lettuce, spring cabbage, salad onions, salad leaves, beetroot and radishes as they mature. You can continue with successional sowing of salad crops, to ensure an even supply over the season.

Be alert to late frosts, horticultural fleece should provide sufficient protection. 

After all risk of frost has passed, plant out tomatoes, courgettes and pumpkins that were previously sown under cover.
Self-blanching celery can also be planted out towards the end of the month.

Earth up potatoes.

Start to remove sideshoots from cordon tomatoes that were started off early under cover.

Thin out sowings of Florence fennel made last month.

Pinch out the tips of broad beans once they start to flower.Strings stretched along the tops of broad bean plants will help to support them.

Peas need staking with pea sticks, netting, or pruned twigs from the garden.

Control weeds to prevent them competing for moisture and nutrients. Hoe regularly between rows on hot days.