April brings longer days and warming soil, but patience remains vital as gardeners balance fresh sowings with the lingering threat of late frosts
April at last! Just a few jobs to do in the garden this month. Start by giving your trees and shrubs a boost by lightly forking a slow-release fertiliser into the soil surface. Roses will also benefit from a dedicated balanced rose fertiliser.
As the soil begins to warm, night frosts are still a threat – resist the urge to plant out too early! Check forecasts and protect early outdoor sowings with horticultural fleece if temperatures dip.
Sowing and planting
A cold greenhouse is now warm enough to start sowing annuals and biennials, including foxgloves, hollyhocks, nemesia, rudbeckia, and French marigolds. Sunflowers can also be started now, either in pots undercover or sown directly into finely raked soil. They are perfect for children to grow and excellent for pollinators and birds: while famous for their height, there are many interesting dwarf varieties now available.
Sweet peas can be sown outdoors this month at the base of their supports. To encourage a bushier plant with more flowers, pinch out the growing tips of any sweet peas you have currently in the greenhouse or cold frame. If you have dahlias started in pots, or dormant tubers, these can safely be planted out during April.
Perennials and bulbs
Place support frames or pea sticks over tall perennials now: doing this early allows the new stems to grow through the supports, hiding them from view. This is also the ideal time to plant summer-flowering bulbs such as gladioli, begonias, lilies, crocosmia and freesias. If you wish to increase your stock of primroses, lift and divide them now: they are hardy plants that split easily to fill gaps around the garden.
Lawn care and pruning
Your lawn will need regular attention from now on. Sow fresh seed on any bare patches and aerate compacted areas by spiking the turf with a garden fork or aerator.
There is still time to prune hydrangeas: cut back to a strong stem and for more plants simply push the cuttings into sheltered soil to root! Once spring-flowering shrubs like forsythia, winter jasmine, and chaenomeles fade, prune them by a third and feed. Conversely, lavender and grey-leaved shrubs prefer poor soil and don’t need feeding – but they do require a light 5cm trim to prevent them from becoming leggy.
Hanging baskets
Later in the month, start making up hanging baskets in the greenhouse. Keep them undercover for protection, only moving them to their outdoor positions once the danger of frost has passed.
