Garden work for May
Unless there is prolonged rain (which can happen!) water all newly planted trees and shrubs with a bucket of water every 4 days for a 2m tree.
Clip evergreen hedges but make sure you will not disturb birds
Once the danger of frost has passed, plant out cannas and dahlias.
Finish planting summer bulbs like gladioli.
Divide congested groups of daffodils when not flowering and leaf growth is finished.
Spiraea should be pruned by up to one-third to allow light and air in.
Cut back mildewed pulmonaria leaves to ensure health new growth.
Acclimatise tender plants by covering with horticultural fleece at night for about a week so that they can get used to outside conditions.
Divide waterlilies if they are not flowering well.
Provided your asparagus is established you can start cutting now.
Runner beans and zucchini should be sown early on. Because our garden is a veritable slug and snail city (even though we have a lovely lot of thrushes who help keep the snails under control) we generally start our runner beans in the greenhouse and plant them out at the end of the month. To give runners the best chance, sow them individually in the divided plastic trays (24 to a seed tray). Try to get the beans out before they start shooting too much and become tangled up with each other.
Remember to earth up your spuds by about 10cm when the shoots are well above ground.
Early on in May complete sowing cucumbers, courgettes and squashes in pots for planting out at the end of May/beginning of June.
Make sure you have a succession of lettuce and other salad crops by sowing a small amount every 10 days or so.
To control codling moth in apple trees hang up pheromone traps.
Make sure radish and brassica do not dry out to ensure good growth.
For heavy strawberry crops give them a tomato (high potash) liquid feed every week or two.
Support broad beans with a strong string and post structure.
At the end of the month, plant out sweet corn. Make sure that they are squares, rather than rows to ensure pollination.