Hoe weeds as they appear. Dead head spring flowering bulbs as they finish flowering. If daffodils have flowered poorly, lift and divide bulbs, replanting the larger bulbs.
Prune spring flowering clematis such as Montana’s after they have flowered, but only if you need to control their size. Stake perennials to avoid them flopping later. If you want to delay some perennials from flowering until later in the season, at the end of the month is a good time to do the ‘Chelsea Chop’.
Prune spring flowering shrubs eg, Forsythia and Philidelphus. Wait until the risks of frosts have passed before planting out any tender plants. Carry on mowing lawns, lowering the height of cut. Feed lawns with a Spring/Summer fertiliser.
Apply a straw mulch around strawberry plants, and feed them with tomato feed every week/every two weeks. Put supports in place for peas and broad beans. Don’t risk planting tomato plants outside until the temperatures are above 12˚C as they are not happy if it is too cold.
Plant out marrows and courgettes at the end of the month. Hang pheromone traps in apple trees to reduce the risk of coddling moth caterpillars entering and damaging the fruit.