May Gardening Tips

Go on garden tours and visit arboretums and garden centers to gain new ideas about plant materials and design.

Plant

Bare-root plants, evergreens, container-grown trees and shrubs (including roses), ground covers, perennials, annuals, tropical water lilies.

Continue to plant summer bulbs.

Transplant summer bulbs.

Transplant summer bulbs potted up in April after danger of frost is past.

 

Prune

Needle evergreens putting out new growth.

Complete pruning of spring-flowering trees and shrubs.

Train and trim espaliers and topiaries.

 

Fertilize

Needle evergreens with 5-10-5 or 10-10-10 (lightly, after pruning),

Roses with 5-10-5 or aged manure (monthly).

Annuals and container plants with water-soluble fertilizer.

 

Watch for

Anthracnose, aphids, bag worm, black spot, black vine weevil, hemlock wooly adelgid, lace bug, leaf beetle, leaf miner, mildew, mites, rust, sawfly, scab, scale, slugs, tent caterpillar.

Lawn care

Complete major lawn work. Feed new and established lawns with 12-6-6. Set mower at 2 1/2” to 3”.

Mow and water regularly. Leave short clippings to aid in nourishing lawns. Compost long, heavy clippings.

 

Bulb care

Deadhead bulbs, but leave the foliage to mature and turn yellow before removing to aid in nourishing bulb.

 

Rose care

Begin summer rose care program of deadheading, spraying, and watering.

 

Chores

Finish spring cleanup. Mulch newly planted trees and shrubs with wood chips, shredded bark, salt hay, gravel.

Mulch azaleas, rhododendrons, laurel, pieris with a thick acid mulch (pine needles, oak leaves, compost).

Dig and divide early blooming perennials after flowering.

Pinch back chrysanthemums and asters to thicken plants and delay blooms.

Set stakes, poles or trellises for floppy perennials and vines

Begin weeding.

Compost garden cuttings unless diseased. Add a layer of 5-10-5 and keep moist to hasten decomposition.

Begin watering if season is dry. Put fish out in lily ponds

 

In the Vegetable Garden

Sow warm-season vegetables and herbs. Transplant warm-season vegetable seedlings to the garden.

Set cutworm collars.

Watch for cutworm, cabbage worm, other caterpillars and leaf miner.