May: To Do in the Garden

by Gary Crispell, EMGV

Rhododendron in bloom. Photo by A. Laine.

Ahh, May. The lovely month. The month for mothers, proms, college graduations and the first great beach weekend—Memorial Day. It is generally not too hot and rarely too cool. The month of balmy days that lead to enchanting evenings on the veranda (deck, patio, veranda—whatever). Enjoy the evening.  There’s gardening to be done on the morrow.

Lawn Care
Warm season grass people: It is your turn. If you didn’t fertilize the lawn in April, get to it. A good slow release fertilizer that meets the requirements notated in your SOIL TEST results is in order. Also, sharpen those mower blades.

Cool season grass folks: Just mow it, but not less than 3 inches high. “Do not,” he repeated, “fertilize cool season grasses until Fall.”

Fertilizing
Speaking of fertilizing; long season vegetable crops like tomatoes, beans and squash (among others) will benefit from a side dressing six to eight weeks after germination. (What?! You didn’t start your own from seed? You bought plants at a Big Box? Give them a week or two in the ground and then side dress.)

While you have the bag open throw some fertilizer at your summer annuals and perennials, too.

Azaleas and rhododendrons and camellias and other ericaceous (acid-loving) plants will benefit from a shot of acid fertilizer about now.

Planting
May is the second-best time in the veggie garden. (Everybody knows harvest is the best time.) It is time to plant beans (snap, pole, bush limas, etc.), cantaloupe, cucumbers, eggplant, okra, southern peas, peppers—sweet and hot, pumpkins, squash, watermelon and, for you non-competitive types, tomatoes.

Gladioli bulbs may be planted now as may begonias, geraniums and other annuals that you didn’t plant in late April.

Pruning
Spring flowering shrubs (e.g. azaleas, camellias, etc.) may be pruned as soon as the blooms fade.  Azaleas may be pruned until July 4th without cutting off next year’s buds.

Overgrown hedges can still be pruned.

Keep pinching back garden mums until mid-July.

Hand prune azalea and camellia leaf galls. They are generally not harmful to the plant, but are unattractive.

I realize your grandmother always cut back the daffodils and iris and other spring bulbs as soon as the flowers faded. I urge you to resist the temptation to carry on that tradition. The bulbs need that foliage to make the sugars that will provide the energy to bloom again next year. Wait until the foliage itself yellows before whacking it off and relegating it to the compost heap. The bulbs thank you.

Spraying

  • Always, always ONLY spray when necessary and READ & FOLLOW label directions.
  • Monitor rhododendron species including azaleas for borers. Spray if necessary.
  • Spray iris beds for iris borers which you probably will not see.
  • Scout for and spray as necessary for bag worms. They are on the move this month.
  • May is a good time to begin to try to eliminate poison ivy/oak (Rhus radicans) and Japanese honeysuckle (Lonicera japonica). Best wishes.
  • Begin spraying squash vines for borers.
  • Monitor the blueberry plants for borers. Spray as necessary.
  • Continue the never-ending spray programs for roses, fruit trees and bunch grapes.
  • Other insect pests active now include azalea lace bugs, boxwood leaf miners, euonymus and tea scales, spider mites (especially on coniferous evergreens), the ubiquitous aphids and the bane of my gardening existence—white flies.
  • If (or more likely when) your tomatoes show signs of blight, begin a fungicide regimen.

Other Things To Do in May That Could Quite Possibly Include the Garden

  • Dance around a May pole.
  • Celebrate Cinco de Mayo.
  • Mulch stuff.
  • Put out a flag on Memorial Day and thank a veteran.