Monthly Tips and Tasks

  • Deadhead bulbs and spring flowering perennials as blossoms fade.
  • Watch for bagworms feeding on many garden plants, but especially juniper and arborvitae.
  • Thin seedlings to proper spacings before plants crowd each other.
  • Plant tropical water lilies when water temperatures rise above 70 degrees.
  • When night temperatures stay above 50 degrees, bring houseplants outdoors for the summer.
  • Apply a balanced rose fertilizer after the first show of blooms is past.
  • Rhizomatous begonias are not just for shade. Many varieties, especially those with bronze foliage, do well in full sun if given plenty of water and a well-drained site.
  • Most houseplants brought outside prefer a bright spot shaded from afternoon sun. Check soil moisture daily during hot weather.
  • Apply organic mulches as the soil warms. These will conserve moisture, discourage weeds, and enrich the soil as they decay.
  • Apply a second spray for borer control on hardwood trees.
  • Softwood cuttings can be taken from trees and shrubs as the spring flush of growth is beginning to mature.
  • Continue spraying roses with a fungicide to prevent black spot disease.
  • Tired of the same old foundation plantings? Find fresh ideas among the evergreens planted in the Dwarf Conifer collection.
  • Trees and shrubs may still be fertilized before July 4th.
  • Pruning of spring flowering trees and shrubs should be completed before the month's end.
  • Water turf as needed to prevent drought stress.
  • Mow lawns frequently enough to remove no more than one-third the total height per mowing. There is no need to remove clippings unless excessive.
  • Gradually increase the mowing height of zoysia lawns throughout the summer. By September, the mowing height should be 2 to 2.5 inches.
  • Mow bluegrass at 2 to 3.5 inch height. Turfgrasses growing in shaded conditions should be mowed at the higher recommendations.
  • Zoysia can be fertilized now while actively growing. Do not exceed 2-3 pounds of actual nitrogen fertilizer per l000 sq. ft. per year.
  • Repeat plantings of corn and beans to extend the harvest season.
  • Plant pumpkins now to have Jack-o-lanterns for Halloween.
  • As soon as cucumber and squash vines start to 'run,' begin spray treatments to control cucumber beetles and squash vine borers.
  • Set out transplants of Brussels sprouts started last month. These will mature for a fall harvest.
  • Soaker hoses and drip irrigation systems make the most efficient use of water during dry times.
  • To minimize diseases, water with overhead irrigation early enough in the day to allow the foliage to dry before nightfall.
  • Start seedlings of broccoli, cabbage and cauliflower. These will provide transplants for the fall garden.
  • Stop harvesting asparagus when the spears become thin.
  • Control corn earworms. Apply several drops of mineral oil every 3 to 7 days once silks appear. Sprays of Bt are also effective.
  • To maximize top growth on asparagus, apply 2 pounds of 12-12-12 fertilizer per l00 sq. ft., water well and renew mulches to conserve moisture.
  • Oriental fruit moths emerge. They are most serious on peaches where the first generation attacks growing tips. Wilted shoots should be pruned out.
  • Thinning overloaded fruit trees will result in larger and healthier fruits at harvest time. Thinned fruits should be a hands-width apart.
  • Enjoy the strawberry harvest.
  • Renovate strawberries after harvest. Mow the rows; thin out excess plants; remove weeds; fertilize and apply a mulch for weed control.
  • Summer fruiting raspberries are ripening now.
  • Begin control for apple maggot flies. Red painted balls that have been coated with tanglefoot may be hung in apple trees to trap egg-laying females.
  • Spray trunks of peach trees and other stone fruits for peach tree borers.
  • Prune and train young fruit trees to eliminate poorly positioned branches and to establish proper crotch angles.
  • When using any gas powered equipment, be sure to allow the engine a few minutes to cool before refilling empty fuel tanks.
  • A mailbox mounted on a nearby post makes a handy place to store and keep dry any small tools, seeds, labels, etc. frequently used in the garden.

June Pests and Problems

  • Indoor plants moved outside for the summer are very susceptible to scorch and sunburn. Acclimate plants gradually to avoid setting them back.
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Scorch, Sunburn, and Heat Stress
Leaf scorch on Japanese maple leaves (Acer palmatum





  • Early in the month scout for bagworms. If found, treat while the caterpillars are still small and most vulnerable.
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Bagworm (Lepidoptera) on lilyturf (Liriope





  • Dethatch zoysia lawns as new growth begins to keep the lawn vigorous and reduce disease problems. Stop fertilizing cool-season grasses until fall.
  • Prune spring-flowering shrubs immediately after flowers fade so you don’t reduce flowering for next year.
  • Monitor for plant bugs on phlox and treat at the earliest signs to reduce ongoing problems. Mildew is another common problem of phlox and many other ornamentals.
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Phlox Bugs
Phlox bug damage (Hemiptera) on phlox (Phlox
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Powdery Mildew - Outdoors
Powdery mildew on azalea (Rhododendron



  • Scout for Japanese beetles and lacebugs.
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Japanese Beetle
Japanese beetles (Coleoptera) feed on over 300 species of plants 
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Lace Bugs
White flecking on upper leaf surface on azalea (Rhododendron) caused by feeding of lace bugs (Hemiptera); heavy infestation 
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Lace Bugs
Adult oak lace bug (Hemiptera ) on underside of bur oak leaf (Quercus macrocarpa

  • Continue to treat for black spot of roses on susceptible varieties. You may also find damage from rose slugs and leaf cutter bees. Usually both are minor and don’t require treatment.
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Black Spot of Rose
Yellowing rose (Rosa) leaves with black spots are characteristic of black spot of rose 
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Rose and Pear Slugs (Sawflies)
Rose slug, a sawfly larva (Hymenoptera), and feeding damage on upper leaf surface of rose (Rosa) leaves 
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Leaf-cutter Bees
Characteristic damage of leafcutter bees (Hymenoptera) along edges of rose leaflets (Rosa

  • Scout for damage from thrips and leafhoppers.
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Thrips - Outdoors
Close-up of damage from thrips (Thysanoptera) on privet (Ligustrum
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Leafhoppers and Planthoppers
Leafhopper nymph (Hemiptera) on squash (Cucurbita) leaf 
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Leafhoppers and Planthoppers
The damage on this silver maple leaf (Acer saccharinum) is typical of feeding by leafhoppers (Hemiptera) but it could be caused by a true bug 

  • Common pests in the vegetable garden this time of year are cucumber beetles, squash vine borer, and squash bugs.
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Cucumber Beetles
Adult twelve-spotted cucumber beetle (Coleoptera) 
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Squash Vine Borer
The rotted crown of this summer squash plant (Cucurbita) was caused by squash vine borers (Lepidoptera) 
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Squash Bug
Squash bug (Hemiptera) on yellow squash (Cucurbita
  • Pollination problems of cucurbits can occur and flea beetles can be a problem on eggplants and many other plants.
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Pollination Problems of Cucurbits
Poor pollination can cause cucumbers (Cucurbita) to be misshapen and stunted. 
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Flea Beetles
Flea beetles damage (Coleoptera) to leaves of eggplant (Solanum melongena



  • The mimosa webworm may cause damage to mimosa and honeylocust trees.
  • Apply controls for apple maggot now.
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Apple Maggot
Apple maggot (Diptera) peeking out of its tunnel in an apple (Malus





  • Watch for clematis wilt, vinca stem blight, and peony blotch.
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Clematis Wilt
Clematis wilt progressing up a clematis vine 
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Vinca Stem Canker
Dead area in periwinkle bed (Vinca) caused by stem canker 
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Peony Blotch
Peony blotch on peony (Paeonia

  • Squirrels are making nests now and dropping leafed twigs. The remains of their feeding on horned oak galls may also be observed.
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Leafy squirrel's nest in tree 
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Gouty, Horned and other Twig Galls
Horned oak gall on pin oak (Quercus palustris) is caused by a type of wasp (Hymenoptera)