May Top Tips


• Begin planting warm season annuals.
• Fertilize annuals bi-weekly with Miracle Gro liquid fertilizer or apply Osmocote slow release granular 14-14-14 (good for 4 months).

• Begin to pinch back mums to promote bushy growth and more blooms. Repeat every two weeks throughout the season until July 4. Up to 1/3 of the foliage can be removed each time.
• Divide hardy water lilies and other perennial water plants.


• Plant summer bulbs such as caladiums, dahlias, cannas, elephant ears and gladiolus and fertilize with bone meal or 6-6-9 fertilizer.
• Once spring bulb plants have flowered, cut off old blooms (do not allow to set seed) and allow the foliage to die to the ground naturally or next year’s flower production will decline. Bulbs can be moved once the foliage dies. Fertilize with bone meal or 6-6-9 fertilizer.


• Take houseplants outdoors when nights will remain above 50F. Most prefer only direct morning sun and can be gradually moved to full sun areas if necessary for the plant.


• Begin planting sweet corn as soon as white oak leaves are as big as squirrel ears. Isolate sweet, super sweet and popcorn varieties to prevent cross pollinating.
• Make new sowings of warm-season vegetables after harvesting early crops.
• Set out tomatoes, peppers, eggplants and sweet potatoes after soils have warmed—usually mid to late May.
• Growing lettuce under screening material will slow bolting and extend harvests into hot weather.
• Remove rhubarb seed stalks as they appear.
• Keep asparagus harvested for continued spear production. Control asparagus beetles as needed. Use permethrin when needed.
• Watch for striped and spotted cucumber beetles now. Both may spread wilt and mosaic diseases to squash and cucumber plants. Treat early on permethrin.
• Control caterpillars on broccoli and cabbage plants by hand picking or use biological sprays such as B.T. or permethrin.
• Place cutworm collars around young transplants. (Collars are easily made from aluminum foil.) Cutworms can also be prevented with permethrin granules.


• Weed & Feed can be applied if you haven’t already done so. The earlier the better! (Must be applied to a wet lawn, then don’t mow for 24 hours.)
• Watch for sod webworms emerging at the end of the month. The first indication of them is usually birds pecking in the grass. The webworms cause saucer sized brown patches throughout an area. The leaf blades are chewed off at soil level. Treat affected areas with Permethrin soil insecticide.
• Treat slugs in your garden with organic diatomaceous earth.


• Monitor pines, especially scotch and mugo for sawfly activity on new shoots. Treat with permethrin.
• Canker worms (inch worms) rarely cause permanent damage to ornamentals. Use B.T. or permethrin.
• Scale crawlers are active this month. They look like small black, brown or white hard discs on stems. Infested pine and euonymus should be treated with horticultural oil at this time.


• Prune unwanted shoots from fruit trees as they appear.
• Mulch blueberries with pine needles, rotted sawdust or peat moss. Feed monthly during growing season with aluminum sulfate—they are very acid loving plants.