Spring
Ground frosts are still around so hold off in planting out until, for me at least in South Wales, the second half of the month. Crops such as sweetcorn can be planted out if protect can be erected.
Keeping on top of the seasonal tasks becomes even more important. As the ground warms up the weeds will burst into growth and in a matter of a week or two your garden can be overgrown. Constant weeding is important now more than ever.