June Garden Calendar

Trees & Shrubs

Prune all dead, damaged or diseased branches any time of the year. As weather becomes hot and dry, water deeply any trees or shrubs that have been planted within the past year. When pruning diseased limbs, disinfect your pruners between cuts. Use a 1-to-10 solution of bleach to water, or use the original Lysol (contains o-benzyl p-chloro phenol) diluted according to the bottle instructions.

Prune the flowering shrubs that bloomed in May after blooming and before flower buds form for next year. Also, prune boxwood and aucuba.

Large deciduous or evergreen trees should be pruned by a certified arborist. These include flowering trees such as cherry, crabapple, dogwood, peach, pear, plum, redbud and fringe tree, and evergreen trees such as pine, spruce and hemlock.

Diseases and Pests that Commonly Appear in June

  • Anthracnose on trees: Symptoms are dead areas or browned blotches on the leaves. On some trees (like ash) the diseased leaves will drop, and the tree will leaf out again. Other forms of anthracnose can be much more serious. Discula anthracnose on dogwood and Sycamore anthracnose can also affect buds and twigs, moving into stem tissue and causing stem cankers.
  • Physiological leaf scorch: Symptoms are browned leaf margins and tips. On some plants, there is also an overall yellowing of leaves. On hydrangeas, symptoms can also include irregular, dry, brown blotches and spots that appear burned.
  • Cedar rusts: Look for galls or orange tubular structures on Eastern cedar or other trees or shrubs in the juniper family. On apples, hawthorn, quince and others, look for yellow orange spots on leaves.
  • Rose slugs: The damage appears as irregular translucent or tan spots on the leaves. Eventually, the damaged areas die, and the spots become holes.
  • Black spot on roses: Black spot begins as small, black spots with indistinct “feathered” margins. Spots expand up to about half an inch and sometimes coalesce. The leaf usually turns yellow, starting around the spots. This disease can cause severe defoliation of the rose bush.
  • Euonymous scale: The tiny insects appear as a white and brown waxy crust on stems and leaves. The brown, oyster-shape scales are the mature females, and the more populous slender white ones are the males.

For more information on pests and diseases of June, see the June Diagnostic Lab Preview.


Mow Kentucky bluegrass and perennial ryegrass to 1.5-2.5 inches, and tall fescue to 2-3 inches. As the weather heats up, raise the cutting height to the higher number in these ranges.

Mow zoysia grass and bermudagrass to 0.5-1 inches.

Use a mulching mower and leave the clippings on the lawn to return nutrients to the soil.

Cool Season Grasses
(fescues, bluegrass, ryegrass): If you have this type of grass, you can relax a bit. Most of the broadleaf weeds have stopped growing so there is little reason to apply post-emergent weed killer. Look out for the emergence of crabgrass (treat with a product containing quinclorac) and yellow nutsedge (treat with a product containing sulfentrazone). If the weather is dry, irrigate at the rate of 1 inch of water per week in the early morning to maintain green, or allow lawn to go dormant. It will green up again in September. Do not fertilize this month.

Warm Season Grasses
(zoysia grass, bermudagrass): If this grass was damaged during the cold winter months, this is the time to cultivate, dethatch, fill bare spots, or plant an entire lawn of warm-season grasses. Early June to mid-August is also time to begin your fertilization program. Apply 0.5 to 1 pound of water-soluble nitrogen to the lawn every three or four weeks..

Vegetable Garden

Your spring planting should have been completed by the end of May. However, it is not too late to transplant tomato, pepper and eggplant seedlings. If your tomato seedlings have flowers prior to transplanting, pinch off the flowers. Bean, cucumber and squash seeds can still be planted in the ground.

Harvest what remains of cool-season crops such as peas, lettuce, broccoli, cauliflower and herbs, such as cilantro. Harvest lettuce early in the day when it is crisp. Once lettuce starts to set flower stalks, it becomes too bitter to eat. Harvest peas late in the day for best flavor.

Before using any pesticide, make sure you have properly identified the disease or pest. FCMGA plant clinics and Diagnostic Lab will help you with this.

Your garden will need 1 inch of water per week, either by rain or irrigation or both. Tomatoes may require 2 inches. Water more during periods of high temperatures and drought. Most herbs need less water and no fertilizer.

Fall Vegetable Planning
Plan now for the fall vegetable garden because some of it must be planted in early July. Planning should include the date of the first frost of fall. In Fairfax County, the first frost on the east and south side of I-395 and I-95 corridor occurs between Nov. 8-28; on the north and west, it occurs between Oct. 19-29. This gives a growing season of approximately 105 days to the east and south of the dividing line and 90 days to the north and west. Providing about a week for seeds to germinate at the beginning and about two weeks for harvest at the end, select vegetables that mature within the remaining timeframe.


To minimize loss of flavor, pick your strawberries early in the day. Do not remove stems or wash berries until you are ready to use them. Blueberries will be ready for harvest in June and should be picked every seven to ten days. Do not pick those with a red tinge, because they are not ripe.

For information about raspberries, see Raspberries in our Mid-Atlantic Region.

Flowering Annuals, Perennials

It is not too late to plant bedding annuals. Begin staking plants that will grow tall (e.g., cosmos) when they reach one-third of their mature height.

Remove spent flowers of cosmos, zinnia, marigold, scabiosa and others to maintain plant vitality and keep them flowering.

Before using any pesticide, make sure you have properly identified the disease or pest. FCMGA plant clinics and Diagnostic Lab are at your service for this purpose.


Don’t take your houseplants for granted. Inspect them regularly to detect the onset of pest problems. This month, you may begin to see small numbers of aphids, whiteflies, mites or mealy bugs. Keep the problems from exploding by bathing the plants in a spray of warm water or water containing an insecticidal soap. Make sure to wet all parts of the plant thoroughly. A cotton swab dipped in rubbing alcohol is good for removing small numbers of mealy bugs and aphids. Take care not to overdo it with the rubbing alcohol; too much will harm some plants.
A Guide to Successful Pruning, Shrub Pruning Calendar, VCE Publication
A Guide to Successful Pruning, Deciduous Tree Pruning Calendar, VCE Publication
A Guide to Successful Pruning, Evergreen Tree Pruning Calendar, VCE Publication
Maintenance Calendar for Cool-Season Turfgrasses in Virginia, VCE Publication
Mowing To Recycle Grass Clippings: Let the Clips Fall Where They May, VCE Publication 430-402
Maintenance Calendar for Warm-Season Lawns in Virginia, VCE Publication 439-522
Spring and Summer Lawn Management Considerations for Cool-Season Turfgrasses, VCE Publication 430-532
Vegetable Planting Guide and Recommended Planting Dates, VCE Publication 426-331
June Tips, Vegetables, VCE Publication
Vegetable Gardening in Containers, VCE Publication 426-336
Vegetable Gardening in Containers, Texas A&M Extension Publication E-45 3-09