Rake and Remove Debris
Rake out dead leaves and branches from beneath the azaleas and rhododendrons. The debris may harbor eggs and fungal spores from last year's pests. Don't put the material on the compost pile. Discard it as yard waste according to your town or city's policy. Use degradable paper bags if permitted.
Leave a Margin for Mulch
When applying wood mulch, leave 8 inches between the mulch and the base of your home or any building. Mulch directly against a building can be troublesome because mulch can contain insects including native (not invasive Formosan) termites that could infest building wood. Leaving an open buffer area helps to reduce that possibility. If you see eggs and ant-like critters in a bag of mulch, don't panic. Though they're not likely to be the Formosan type, it's a good idea to notify the store and your local Extension agent as a precaution.
Feeding Shrubs and Perennials
After removing leaves, dead branches, and other debris from beneath the evergreens, give them a spring boost - slow-release fertilizer. Azaleas, rhododendrons, and hollies might need an acidic fertilizer (for example, Espoma HollyTone) and iron; apply as directed. Used coffee grounds are a good acidic fertilizer; just sprinkle them on the soil. Be sure to check the soil pH (acidity or alkalinity) at the shrub's root zone, though. State Extension services provide soil testing at reasonable cost. Quality garden centers may do free pH testing if you bring in a soil sample.
Top-Dress Bulbs as Leaves Emerge
For healthier plants now and better bloom NEXT year, lightly fertilize spring- and summer-flowering bulbs as shoots emerge and after the soil has thawed. A specially formulated, slow-release bulb booster, bulb tone, or bulb food is best, but 5-10-10 is okay in a pinch. Do not fertilize spring-flowering bulbs near flowering time or after bulbs finish flowering. They need to go dormant for the summer, and fertilizer will encourage growth.
Pot Up Tender Bulbs
Check the tender bulbs -- dahlias, tuberoses, cannas, gladioli, caladiums, elephant ears -- you stored in peat moss last winter. Pot up the ones starting to sprout. This will give them a head start. Keep them indoors in a sunny spot or under a grow light until there's no chance of freeze. When warm weather's certain, transplant them into the garden and display them in containers.