1Divide herbaceous perennials
Divide clumps of herbaceous perennials that you want to propagate, those that have become too large for their allotted space, and those that are flowering poorly or have lost their shape.
Prune out old stems of elder (Sambucus) to promote new growth from the base.
3Make runner bean supports and trenches
Start preparing runner bean supports and trenches for sowing (in May) or planting out (in June).
Divide hostas before they come into leaf.