05/15/2026
May Garden Tips & Planting Advice
Dead-head tulips.
Mow grass when it reaches 3-4 inches. Set the mower to 2 1/2 to 3 inches.
Hold off mulching until the soil is warm.
Plant lettuce, beans, corn and carrots.
Plant tomatoes when the lilacs bloom. Sprinkle a teaspoon of Epsom salts into the hole where they go to provide magnesium.
Plant marigolds, zinnias and nasturtiums in and around vegetables and flower beds to repel insects. Plant gladiolas at 2 week intervals.
It's time to w**d dandelions, before they flower and set seed.
Fertilize any bulbs that are up.
Stake peonies and other tall growing plants before they get too big.
Cut back tall perennials like bee balm and phlox to control height.
Harvest rhubarb by grabbing it at the base of the stalk and pulling firmly away from the crown, twisting just a bit. Be sure to throw the leaves into the compost as they are poisonous. Prune spring blooming shrubs just as soon as the flowers have faded. Deadhead lilacs. Check lilies for red lily leaf beetles. Dispose of them by crushing them.
Don't forget to deadhead bulbs as well. Leave the foliage, but take out the spent flower heads. Slugs chewing the hostas? Combine 9 parts water to common household ammonia and spray it on just before dark. When the slugs hit this, they will dissolve.
Check apple, cherry, and other fruit trees for tent caterpillars. As soon as the tender new leaves emerge so will the caterpillars. If you have to spray with insecticide do it after bloom is finished to protect the bees.
Plant annuals no sooner than May 30th.
https://www.andovergardenclub.org/a-new-england-garden-by-the-month