June Garden Tips

June Tips

June celebrates summertime!  Most gardeners have started their summer plantings and maintenance.  With the warmer weather upon us, water at cooler times to conserve water.

Indoor Plants

  • Keep plants away from air conditioner drafts.
  • Going on vacation?  Soak house plants thoroughly and allow to drain.  Place them in a plastic bag and tightly tie the opening.  Sticks in the soil will keep the bag away from the foliage.  Plants such as African violets should have small holes in the bag for air circulation.
  • Make sure you feed your plants now that they are in their growing season.
  • Keep a watch on the individual light needs of your plants.

Lawn and Landscaping

  • It's still not too late to aerate.
  • You may still overseed or reseed stubborn areas.
  • Fertilize now if you didn't during April or May.  Better yet, lay down about an inch of compost.
  • Make sure you add at least 1 inch of water per week if it doesn't rain.
  • When grass reaches 3 1/2 to 4 inches, cut only the top 1 inch with your sharp mower blade and leave the clippings on the lawn for nourishment and to help prevent weeds.
  • Continue to keep a diary of everything you have planted, especially since there is new growth.
  • Watch for areas of your garden that are not doing well, analyze them, and plan for changes.
  • Reuse any containers that support root growth and that provide adequate drainage to spruce up your patio or front porch.
  • Note where shadows fall so that you can later move sun-loving plants.
  • Record which plants have the fewest problems and their growing environments.

Perennials, Annuals and Bulbs

  • It's still not too late to plant annuals such as petunia, coleus, geraniums and impatiens.
  • You may also plant sunflowers, marigold, cosmos, sweet alyssum and zinnia.
  • Be sure to deadhead annuals that have already bloomed.
  • Most herbs need no fertilizer and little water, so water only during prolonged dry spells.
  • You may also plant bulbs of dahlia, canna, tuberous gladiola for later blooms.  Glads may be planted every week from now till early July for continuous displays and cuttings.
  • Perennials that have flowered in the spring can be dug up and divided now to prevent over-crowding.  This includes irises, Oriental poppies, primrose and Coronicum daisies.
  • Pinch off spent blooms to keep flowers coming.
  • If you stayed on top of your weeding, continue to do so.  They will start growing more vigorously now.
  • Take your time and remove weed by hand if possible, especially the flowers.  There will be much less work later.
  • Practice integrated pest management (IPM).  Use pesticides least toxic to fish and wildlife.
  • Try to provide an environment that is beneficial to predatory insects, such as lady bugs, by planting a patch mixture of crimson clover and hairy vetch.
  • For hanging baskets in cool, shady locations, use tuberous begonias, ferns, impatiens or fibrous rooted begonias in combination with trailing plants, such as English ivy.
  • Watch for and control blackspot and powdery mildew on rose foliage.
  • Remove foliage from spring bulbs after it turns yellow and begins to dry.  Set out bedding plants to cover the bare spots using care not to damage the bulbs.

Trees, Shrubs and Groundcovers

  • Summer plantings of shrubs are possible if you use container-grown plants.  Water the newly planted shrubs frequently.
  • Prune rambling and climbing roses after they bloom.
  • Take softwood cuttings now to start new plants of spirea, boxwood and azalea.
  • Make sure that you adequately mulch around trees and shrubs to reduce groundcovers and grasses.
  • Prune out damaged or dead branches on shade trees.
  • Watch for any unusual growth or diseases and contact your Extension agent.
  • If you do not have much room to landscape, consider using some of the many dwarf varieties available.  These are plants that have slow growth and stay small, so there is little pruning maintenance.  There are numerous dwarf evergreens, flowering trees and shrubs from which to choose.
  • Trees and shrubs growing in containers can be planted anytime during the growing season but planting in June gives plants a full season to become established before winter.


  • All herbs can be planted this month.
  • It should be safe now to plant vegetables such as beans, peas, potatoes, lettuce, carrots, corn and chard.
  • Corn, eggplant, peppers and tomatoes should be planted as soon as possible.
  • Start successive plantings of carrots, lettuce, spinach, chard, kohlrabi, beets, parsnips, radishes, turnips, bush beans and peas to expand your harvest season.
  • Keep a close eye on the quality of your spring crops.  Hot weather causes lettuce to bolt and become bitter.  Plant a warm season crop as soon as the spring vegetables are harvested.
  • In most cases, blossom-end rot on tomatoes, peppers, squash and watermelons can be prevented.  Do this by maintaining uniform soil moisture by mulching and watering correctly, planting in well drained soil and not cultivating deeper than one inch within one foot of the plant.  Also avoid the use of high nitrogen fertilizers.
  • Continue planting warm season vegetable crops such as beans, squash and cucumbers.
  • Leftover vegetable and flower seeds may be stored in a cool dry location to be saved for planting next year.
  • Harvest your lettuce, peas, carrots, radishes and onions now.  Plant another quick maturing vegetable or plant more of these varieties for continuous growth.
  • Continue to thin out your lettuce plants.  They should be about a foot apart.
  • If you want best results, this is the last month to plant your warm-season vegetables (eggplant, pepper, squash, tomato and beans).
  • Pinch the tips of your broad beans off to prevent aphids.
  • Transplant Brussels sprouts into the garden now.  Plant approx. 3 ft. apart.


  • ​Aphids are still here.  Knock them off plants with a strong water hose spray or use insecticidal soap spray.
  • Using milky spore disease (Bacillus popilliae) will only be effective if most of your neighbors use it also.
  • Bats can be an effective way to control insects.  One big brown bat can eat 3,000 to 7,000 insects each night.  Attract bats by building and placing bat houses in your yard.
  • Pick up all leaves and faded flowers and add them to the compost.  These are a favorite hiding spot for slugs and snails.
  • Turn and dampen your compost often.  Flies will breed in the grass clippings if you do not turn it regularly.
  • Harvest early season fruits and vegetables including strawberries, lettuce, radishes and peas when they are at the peak maturity.
  • Avoid disease-encouraging conditions by watering early in the day, so plants have a chance to dry off before nightfall.

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