Perennials: Continue dividing, transplanting and staking. After a thorough weeding, mulch the beds with 2 to 3 inches of light material. Continue spraying roses with horticultural oil and a fungicide and feed once a month.
Flowers: The danger of frost should be past, but always keep “a weather eye out.” Purchase tender annuals and plant among the perennials for constant color. For a display in patio pots, use fresh potting soil and a slow release fertilizer. If there is a cold snap cover the plants with flower pots. Deadhead pansies to keep them blooming. Zinnias do not like to be transplanted but can be seeded into peat pots now and will receive little shock when planted out later pot and all.
Vegetables and fruits: Harden off (that is acclimatize to cool nights, direct sun and strong breezes) seedlings of eggplant, peppers, and tomatoes before planting in the garden. To harden off properly, start the adjustment period on a cloudy day — an hour in a sheltered location, then half a day, all day and finally an overnight before planting. Give a water-soluble fertilizer boost at half rate. Wait to mulch until the soil is thoroughly warm.
Trees and shrubs: Broad leaved evergreens are recovering from winter burn, although some older rhododendrons will not recover. Prune out obvious dead wood, but look for green wood that shows life even though the leaves may be brown. Fertilize with acid-type fertilizer, keep watered and mulched. It is normal for hollies, rhododendrons, boxwood, taxus, etc. to shed old leaves now.
Lawns: Do not mow where naturalized bulbs are ripening. Keep lawns mowed at 3 inches. Leaving the clippings can reduce fertilizer requirements by at least 30 percent.
Houseplants: After repotting wait a month or so before fertilizing, until new roots develop. It is too early to transfer houseplants outside.
General: Mother’s Day plant sales are everywhere. A good time to stock up and plant something beautiful for your mother.
Susan Henry is a master gardener with Cornell Cooperative Extension of Westchester