May Tasks

Try to keep ontop of the hoeing and weeding
Feed roses and shrubs with a general fertiliser; rhododendrons and camelias would benefit from an ericaceous feed.
Plant up hanging baskets, but keep them protected in the greenhouse or frost free conservatory and don’t forget to include some slow release fertiliser.
Cut the grass whenever conditions allow.
Plants that are growing in pots would benefit from a feed
If you removed your pond pump last autumn, now is the time to check it over and replace it for the summer.
Trim back shrubs that have flowered over the late winter, eg jasminum nudiflorum, removing the flowered shoots to keep the shrub within its boundaries.
Clean patio slabs and stonework to remove alge etc.
Trim back spreading alpines such as aubrietia and arabis after flowering.
It looks like we may be in for a dry summer so a water butt or other water collection system connected to the guttering is a good idea.