Gardening Tips for May

May 4, 2020

By the end of May we should be frost free, but before then we still need to have a cloche or fleece to hand. Local gardening expert Andy Colquhoun shares some advice about planting out.

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‍Planting out in the vegetable plot:

Broad beans, runner beans, onions, garlic, carrots, salad crops, leeks, strawberries.

Tomatoes: until the frost has passed these are best in the greenhouse. After the last frost then a sunny, but sheltered spot in the garden is fine. Tomatoes need attention to produce a good crop. Fertile soil or peat free potting compost, water regularly and feed weekly with a high-potash fertiliser.

Herbs: ones to plant outside are thyme, rosemary, parsley and mint. You can sow the more tender herbs - basil, coriander, dill, Thai basil and tarragon - in pots under glass ready to plant near the end of the month when it's warmer.

Strawberries: It is best to cover these with nets as the birds love them. You can also spread straw around to protect the fruit from dirt and rain splash (which can cause mould). Cover the strawberries with a cloche through the early growing months as extra shelter aids an early crop.

Planting out in the garden:

All hardy perennials, evergreens and hardy annuals.

Sweet peas: if dead-headed and looked after, sweet peas can last into October and are well worth the money for their long flowering time. They can be put out in April and May, but may need to be hardened off first (introduced slowly to the cold). They are a great way of colouring borders and, with use of a trellis or obelisk, really give added height and scent to an area. Sweet peas like moisture and a good tip is to line the trench with newspaper to add extra moisture retention. If sweet peas get too dry, they are prone to mildew.

Bedding plants: the end of May is generally the best time to plant out bedding plants, but be careful – if it's too cold the plants will sulk. Best time to plant out is when it is warm, sometimes I put them out and bring them back into the greenhouse on cold days. Or just leave them in the greenhouse until nearer the end of the month. They soon acclimatise.

An ideal time to feed plants. For plants in containers, you can feed them without repotting by putting fertiliser on the surface and gently working it into the soil. Also, you can top dress your container, by taking out the top couple of inches and adding new compost and fertiliser. For shrubs and roses sprinkle fertiliser around the base and fork in.