June Gardening Tasks
Expand the categories below to learn more about what you need to do this month.
Vegetables
Continue to plant heat-loving herbs including basil, Mexican tarragon, and rosemary. Pinch back basil and tarragon regularly to prevent flowering and enhance branching.
Make trellises or use stakes for tomatoes, cucumbers, pole beans and other climbing crops.
Keep an eye out for stinkbugs, leaf-footed bugs, bean beetles, tomato and tobacco hornworms, tomato fruitworms, flea beetles, corn earworm, cucumber beetle, and squash vine borer in the garden.
Harvest onions, garlic and potatoes from the spring crop. Check your tomatoes and other susceptible crops for blossom end rot on the fruit as it begins to form. This is usually an indication of calcium uptake issues complicated by uneven moisture and possibly other factors. Contact the Master Gardeners at the Hall County Extension Office for advice on how to deal with this disorder.
Use bird netting as needed to help protect ripening tomatoes and strawberries from hungry birds and other critters.
Monitor and treat garden fire ant nests as you find them. Use a spinosad-based bait, drench or a combination (add bait and then drench in a week or two). Spinosad is a natural insecticide and is safe to use around vegetable plots and other edibles.
Some planting times for more common vegetables:
Cantaloupe – March 20 – June 20
Melons - March 20 – May 1
Okra – April 1 – June 1
Pumpkins – May 15 - Jun.15
Southern peas – April 1 – August 10
Sweet potato – April 15 - June 15
Fruit Trees
Continue inspecting rosacaceous fruit trees (apples, pears) for fireblight. Prune as needed. Understand that the best defense is to use a fireblight-resistant variety.
Apple, pear, peach and plum all benefit from fruit thinning. Remove enough fruit so that there is no more than one fruit for every eight inches of shoot length on pears, apples and peach trees. On a plum tree, fruit can be spaced four inches apart. Pears and apples bear fruit in clusters. Removing fruit so that only one fruit per cluster remains is a common practice. If you don’t thin, you could experience fruit drop. Fruit drop is a natural process for many fruit crops and is the tree’s way of relieving stress of a heavy fruit load.
Use bird netting as needed to protect blueberries and strawberries from hungry birds and other critters.
Monitor and treat fruit tree or strawberry bed fire ant nests as you find them. Use a spinosad-based bait, drench or a combination (add bait and then drench in a week or two). Spinosad is a natural insecticide and is safe to use around fruit trees, blueberries, bramble fruit and other edibles.
Blueberries can still be pruned in June without harming next spring’s buds. Generally, prune other fruit trees when dormant.
Lawns
For shady areas where grasses don’t grow well, but mosses do, try replacing it with versatile ground covers like liriope, mondo grass, ferns or hostas. Of course, some kinds of zoysiagrass varieties and all types of centipedegrass tolerate bright shade part of the day. ‘Tifgrand’ Bermuda is also said to tolerate a little shade. Cutting back low hanging branches to let in more light sometimes helps if you want to stick with turfgrasses.
If you plan to plant a warm-season (centipede, zoysia, Bermuda, St. Augustine) lawn, the best time to plant is in the spring and summer. It's getting too late to plant Bermuda by seed (unless you seed with unhulled seed in the fall). Wait until the coming fall for cool-season grasses (fescue).
You can apply nitrogen to Bermuda and other warm season lawns this month. You can also apply a slow-release fertilizer to St. Augustine lawns (if you’re brave enough to try this turf species here) to help reduce chinch bug problems.
Remember, anytime your warm season lawn is actively growing is a good time to aerate.
Continue to monitor and treat fire ant nests. There are many insecticide products (baits and drenches) approved to use on lawns.
Continue watching for problems with brown patch and dollar spot in warm season grasses, especially if you had problems with one of them last year. Avoid overfeeding and overwatering.
Inspect warm season lawns for mole crickets this month. Eliminating these critters requires diligent work in June, July, and early August. White grubs are best managed by pesticide applications in late summer.
Make the second attack on your war with grassy weeds like crabgrass and goosegrass this month. You might need an additional application of a pre-emergent herbicide this month to compliment the one applied in February or March. This won’t affect existing grassy weeds, but will impact newly germinating grasses.
Spot treat for broadleaf and grassy weeds, using herbicides appropriate to the turfgrass you are growing.
Let grass clippings fall back into the lawn for nutrient recycling.
Check your mower blade for sharpness and sharpen as needed. Check your lawn mower engine oil and add or change according to owner’s manual.
Flowers
Japanese beetles will defoliate plants in short order. Keep a sharp lookout for them. If you find an infestation use carbaryl (Sevin, etc.), which is very effective. Observe all label precautions on mixing and use. Do not use dusts due to the problem with application - a spray made using the liquid form of the product will work fine. Don’t confuse skeletonizing damage from beetles with sawfly larvae (rose slug, hibiscus sawfly) – use a spinosad-type pesticide or carbaryl for control!
Prune back fall chrysanthemums this month to encourage more branches and bushier growth. Deadhead spent flower blossoms as appropriate to keep plant flowering. Remove flower stalks from iris. Mulch flower gardens for the summer to conserve moisture, control weeds and cool the soil. Water plants as needed. Trim spent rose blossoms. Check all plants for insects. Remove dead foliage from spring bulbs. Water and fertilize container plantings regularly to encourage growth and flowering.
Trees
Many summer flowering shrubs, like rose of Sharon, shrub-type roses and crapemyrtle, benefit from frequent light pruning during the warmer months to encourage further blooming. Azaleas and bigleaf hydrangea can still be pruned in June without harming next spring’s buds.
Mulch around the bases of trees and shrubs to conserve moisture. Water newly planted trees and shrubs as needed . Now you can prune the old yellowing foliage off of spring flowering shrubs. Do not damage tree trunks with mowers and string trimmers. Check for spider mite, scale, mealy bug, and whitefly damage on various shrubs and use appropriate insecticides to treat as needed. Clip hedges as needed to maintain shape.
Bag worms can kill a tree if it is heavily infested. Inspect your trees periodically - bagworms like evergreens such as juniper, arborvitae, and pines, but they will attack many broadleaf shrubs and trees such as rose, sycamore, maple, elm, and black locust. Hand-picking light infestations works well; applying the bacteria Bacillus thuringiensis (kuristaki strain) will also take care of the problem. Also, watch for spittlebugs in warm season lawns and on hollies.
You might plan to apply a second, light fertilizer application to trees this month if there is sufficient moisture and conditions promote good growth. Do not apply if growing conditions are poor or if there is a drought. If you fertilize trees in the summer, this month is the last time you should feed!
If necessary, now is another good time to prune most trees and shrubs. July and early August are the last months to prune azalea, dogwood, forsythia, redbud and rhododendron. They should be pruned after they bloom, but before bloom set in the fall. Avoid any pruning in the spring and fall if at all possible.
Houseplants
Fertilize regularly with a liquid or water-soluble fertilizer throughout the summer months to encourage growth. Wash leaves to remove dust. Take cuttings to start new plants. Prune and shape plants for added beauty. Repot plants as needed in 1" larger containers. Check for insect and disease problems and treat accordingly.
As always, if you have questions about gardening and landscape maintenance, don’t hesitate to call the Hall County Extension Office at 770-535-8293 or email us at mastergardener@hallcounty.org.