- Apply a general-purpose fertilizer around established shrubs and roses.
- Mulch the soil after a rain or watering.
- Stake herbaceous perennials as growth emerges.
- Sow seeds of half-hardy and tender annuals inside, or buy plug plants and grow on in a frost-free place.
- Harden off bedding plants sown earlier in spring.
- Sow hardy annuals in situ.
- In late spring, thin hardy annuals sown inside.
- Plant evergreens, and move any that are in the wrong place.
- Prune early-flowering shrubs and climbers after they have bloomed.
- Cut back ornamental grasses as they start to grow.
- Make new shrubs and climbers by layering.
- Start taking softwood cuttings from new shoots.
- Sod or sow new lawns, and repair worn-out lawns.
- Apply a spring fertilizer, and a weedkiller, to lawns.
- Cut the grass with the blades quite high.
- Keep weeding.
This list was found in Learn to Garden: A Practical Introduction to Gardening. I did modify the list a little.