Garden work heats up this month
June can be filled with so many projects that it often feels important to devote every free minute to the garden. With burgeoning weeds to pluck, mulch to spread, and fading blossoms to snip so new buds will emerge, many gardeners can't imagine pulling themselves away from the welcome demands of pleasant work.
When the American poet e.e. cummings wrote, "the earth laughs in flowers," he must have been thinking of June. Roses, peonies, baptisias, alliums and countless other plants always make this a laughter-filled month.
Trees and shrubs
Fertilize roses with a second application of liquid 20-20-20 fertilizer after the first flush of flowers. Continue to monitor for black spot. Remove infected leaves immediately and begin a spray program with an approved fungicide. Most products must be reapplied following any rainfall.
Deadhead hybrid tea roses as soon as flowers fade. Many shrub roses are self-cleaning and don't require deadheading. When in doubt, lightly prune old blossoms to keep plants looking attractive.
Pinch off 1 inch of sticky new green growth on azaleas and rhododendrons to increase next year's flowers. Mulch these acid-loving plants with shredded pine needles and/or shredded oak leaves.
Continue to prune all spring-flowering shrubs immediately after they flower.
Small evergreens, such as boxwood or yew, can be lightly pruned after the new growth fills in to maintain a formal character.
Flowers
Deadhead annuals and perennials.
Continue to spray emerging summer-blooming lilies with anti-rodent products if rabbits and deer have been a problem. This fall, plant allium, daffodil or fritillary bulbs next to lilies and other deer favorites to discourage browsing.
Fertilize annuals in containers, baskets and window boxes with a quarter-strength balanced fertilizer every seven to 10 days. Always water the plants before adding liquid fertilizer.
Continue to pinch off new growth of chrysanthemums, asters and tall sedum.
Monitor succulent new growth for signs of aphids (puckered stunted leaves). Hose down affected plants to knock off the aphids.
When cutting peony blossoms to bring indoors, remove as few leaves as possible from the plants.
Hand pull invasive garlic mustard before flowers have set seed and when soil is moist, getting as much of the root system as possible. Try to disturb soil as little as possible.
Vegetables and herbs
Stake or cage tomatoes as they begin to grow.
Harvest peas, early raspberries and all cool-season greens and vegetables as they ripen.
If squash vine borer has been a problem, cover small transplants of squash, cucumbers and zucchini with row covers to prevent moths from laying eggs on vines. Remove row covers when plants begin to flower.
Pinch top growth of herbs to keep them from flowering and to intensify the oils and flavor of the foliage. Snip sprigs of fresh herbs for use in cooking all season and to encourage plants to produce more growth. Freeze or dry extra for future use.
Plant pumpkins at the first of the month. If you gently carve names in developing pumpkins, the letters will enlarge as the pumpkins grow.
Lawn care
Seed bare areas of lawn with appropriate grass seed mix and starter fertilizer. Keep area moist until seeds germinate. Do not mow for several weeks until roots develop and new grass thickens up. Mower blades should be sharp to lessen damage to grass that is not fully developed.
Rain and warm water will push grass to grow fast. Mow high (2-to-2 inches) so individual blades of grass can shade each other during the heat. Leave grass clippings on the lawn to decompose and return nutrients to the soil, but break up large clumps that might block sunlight.
If grubs were a serious problem in the past (more than ten to 12 in a square foot), treat the affected areas with a product containing imidacloprid.
Denise Corkery is a horticultural writer for the Chicago Botanic Garden in Glencoe.