Things to do in the garden in May:

In the vegetable garden – Sow seeds of Broad Beans, Cabbage, Turnip, Onions, Spring Onions, Snow Peas, and Peas. Plant Shallots and Garlic. Plant seedlings of Lettuce, Cabbage, Cauliflower, Broccoli, Kale, Brown & Red Onions (this is the best month) Spring Onions. Sow Green Manure mix in areas not required for winter vegetables. Remove all dead beans, old sweetcorn plants,
tomato plants etc., and anything that can carry over fungal infections. Take action to deal with any Cabbage White caterpillars on winter vegetables. Mavrik is probably the most effective and safe. Apply another dressing of Giganic around Cauliflower, Broccoli etc that were planted in March and April.

In the flower garden – Complete the planting of spring flowering bulbs. The ground temperature is probably too low for the germination of most flower seeds, so it is best to plant seedlings of Pansies, Violas, Lobelia, Alyssum, decorative Kale, Primulas, Polyanthus, Cinerarias, Dianthus, Lupins, Madeira Daisies, and Cyclamen. Spruce up the pots on your deck with Primulas, Violas,
Pansies, Cinerarias or some Spring bulbs. Most of the above are also available as potted colour.
Start tidying herbaceous borders, dividing clumps that have grown too large. Prune to shape some of the deciduous shrubs. In frost-prone areas, don’t prune the dead heads off Hydrangea until after frost as they protect the new developing buds. Decide which roses need replacing. Dig them out, together with a barrow full of soil. Replace with new soil and well-rotted manure or
Mushroom compost. Put Seamungus in the bottom of the hole when planting new bare-rooted varieties. Leave pruning of roses until mid-June and planting new roses until June/July. An application of Kahuna now around Camellias will improve both the colour of leaves and size and colour of blooms.

Lawns – Continue repairing worn patches, apply fertiliser and control weeds. New weeds will germinate in worn patches, and these (especially Capeweed) are best controlled by spraying when small. Do not spray within 4 days before or after mowing. Follow chosen product directions carefully to prevent lawn damage.

Fruit trees – Begin pruning peaches, plums, and nectarines and any other stone-fruit trees.
Provide support for heavily laden branches of citrus fruit to prevent breakage of branches, thinning out if necessary. Look for Scale infestation and Sooty mould. Spray with white oil alone or a mixture with insecticide such as Mavrik, Remove all grass and weeds around fruit trees.