Our tips are based on recommendations from the North Carolina Cooperative Extension Service but also include our own suggestions.
Although the timing differs somewhat, you may also want to view the excellent Missouri Botanical Garden
monthly gardening guides, divided into Tips & Tasks and Pests and Problems. Pests and Problems has photos and
detailed discussions of each problem, emphasizing environmentally-friendly management.
Tips & Tasks
Remember to change direction when mowing your lawn. Travel north to south on one mowing and east to west on the next cutting.
- Mow often enough so that no more than ⅓ of the grass height is cut, and leave grass clippings on the lawn.
Clippings decompose quickly and can provide up to 25% of the lawn’s fertilizer. If grass clippings are too
plentiful, collect and use them as mulch or let them dry a bit and add to your compost pile.
- Mow fescue lawns to 3–3.5″.
- Mow Bermudagrass using a reel mower set at ¾–1″ or a rotary
mower set as low as possible without scalping.
Hopefully, you have read our LAWNS page and properly prepared your cool-season lawn for the heat and drought
that is normal in our area. The page contains detailed watering instructions, which differ depending on whether you are keeping your lawn
green or encouraging dormancy.
If you have a fescue or bluegrass lawn, you can start preparing it now for reseeding in September.
Bermudagrass lawn maintenance calendar
NC CES: AG-431
Tall fescue lawn maintenance
calendarNC CES: AG-367
Tips & Tasks
Do not fertilize woody plants. Fertilization now stimulates new growth that will not harden off properly in the fall and will make your tree or
shrub more likely to suffer frost/freeze damage.
If drought threatens, set priorities. Trees come first, followed by shrubs, then perennials.
- Drought stress occurs when water lost through plant leaves exceeds either the water available to the plant in the soil or the water the plant
is able to absorb via normal physiological processes. Warm summer breezes increase plant water loss. Most plants need 1–1.25” of water
- Hard downpours can run off without soaking in, so plants can need watering even after a 3” rainfall.
- Clay soils absorb water at only ~ ¼” per hour, so soaker hoses are a great way to water. For large areas or lawns, cycle
sprinklers on and off so that water has a chance to soak in and reach the roots: water for 15 minutes, turn off to let water soak in, water
again for 15 minutes, turn off, etc.
- Water deeply to soak the soil 4–6” deep.
- Avoid wetting plant foliage. The best time to water is late night–early morning, which minimizes evaporation and ensures that if foliage
is wetted, it dries quickly. This minimizes conditions that favor fungal disease.
- For trees, water around the drip line and as far as 3x the drip line — even tap-rooted trees usually spread their roots
widely and shallowly in clay soils.
In a sunny location the temperature at the soil surface can be higher than the air temperature and bare soil will rapidly dry out. Mulch plants
to a depth of about 3”, keeping it away from plant crowns, to conserve moisture and suppress weeds.
Cut off the faded flowers of annuals, phlox, shasta daisy and daylily to encourage a second flowering (or for annuals, continual bloom). If
annuals are spindly or leggy, trim them back by as much as ½ their current height to rejuvenate.
Prune “bleeder” trees like maple, dogwood, birch and elm this month. You can prune off water sprouts by gentle rubbing. Prune
off spent crape myrtle blossoms to prolong the flowering period, but only prune branches with a diameter less than that of a pencil.
Do not prune shrubs. Pruning now stimulates new growth that will not harden off properly in the fall and will make your shrub
more likely to suffer frost/freeze damage.
Watch for root suckers on grafted roses and remove them promptly. These represent the rootstock species and not the hybrid you purchased.
Suckers are usually very vigorous and can steal all of the resources from the top graft. They often have foliage that is distinctly different
from the top graft.
- This is still a great time to take semi-hardwood cuttings of azaleas, holly, rhododendron and many other shrubs.
- You can divide and transplant bearded iris.
- While you can safely divide or transplant many daylilies now, some cultivars rot when divided or transplanted in hot, humid conditions. The
problem is not well understood. It is safer to propagate daylilies in mid- to late September.
- Start cool-weather annual seeds indoors for for fall planting. Try foxglove, pansy, alyssum, snapdragons, ornamental cabbage
(kale) and primroses. Pansy seeds germinate well when stored in the refrigerator (not freezer) for 10–14 days before planting.
- Sow perennial seeds of hollyhock, delphinium and stokesia outdoors to produce healthy plants for next spring. Lay the finished flower stalks
of foxglove on the ground where you want new plants to grow or sprinkle the seeds from the dried pods.
- Plant lycoris (spider lily), colchicum (autumn crocus) and sternbergia bulbs.
Pests & Problems
Use preventive measures for blackspot, powdery
mildew, cankers, rust and botrytis on roses. Rugosa and Lady Banks roses are generally immune to disease. See the
Earthkind trials for other genetically resistant,
but not necessarily immune, cultivars. Currently, all roses are considered susceptible to
rose rosette, so monitor for symptoms (especially on
Knockout® roses) and carefully remove infected plants.
Beneficial insects share the same plants as insect pests. Use low-toxicity pesticides when possible, spray only if needed, and
spray at dusk when the bees have all gone home. Always read and follow label directions for safe pesticide application.
- Aphids can attack tender new plant growth. They can
be washed off with a forceful stream of water. Severe infestations can be controlled with the relatively environmentally benign insecticidal
- Lace bugs also can attack new growth, usually only on
azalea and rhododendron, but sometimes on pyracantha, cotoneaster, quince or hawthorne. Dark spots about the size of a pinhead on the lower
leaf surface are diagnostic. The best defense is to plant genetically resistant varieties and to maintain plant vigor. For control of severe
infestations where there is no evidence that natural predators are present, repeated applications of insecticidal soap or horticultural oil can
be effective. When a history of lace bug infestation exists, insecticides can be applied to the lower leaf surface, usually 2 applications
~2 weeks apart. Monitor the plants about once a month for reinfestations.
- Fall webworms are often mistaken for Eastern tent caterpillars, but do no lasting harm to trees.
Tent caterpillars are active only in spring, while webworms become active beginning in mid-summer. Treatment is not necessary, but you can open
the web to expose the caterpillars to predators.
- Slugs can attack soft new growth. Holes in leaves or
on leaf margins and a silvery slime trail in the morning indicate slug damage. Slugs hide under boards, stones or debris
during the day, so populations can be reduced by managing habitat. See the link for additional suggestions.
- Japanese beetles vary in numbers
from year to year. Control by any method is difficult to achieve unless it covers a significant area. This requires careful monitoring and the
coordinated effort of an entire neighborhood. A recommended alternative is to keep plants healthy (weak plants are more susceptible), to
remove beetle attractants such as prematurely ripened or diseased fruit, and to plant resistant species. See the link for details on beetle
lifecycle, monitoring, control, and species susceptibility.
- Kudzu bugs are a new pest from India and China that look
somewhat like an olive lady beetle. They feed on all types of legumes (note that wisteria is a legume) and congregate on figs, magnolias,
bronze fennel, redbuds, roses and peppers. Because they are so new, control strategies are still experimental. Carefully brushing them into
soapy water is one approach (they release an irritant when crushed). Some predatory insects like assassin bugs and predatory stink bugs
appear to be finding them, which may help to control population size.
NC CES has additional information.
- Flatid planthoppers look like mealy
bugs at first glance, but they usually do little damage and do not require treatment.
- Monitor for pests:
remove bags by hand — sprays cannot penetrate them
- Manage vines such as trumpet creeper, blackberry and poison
ivy, and remove “weed” or unwanted trees from your landscape.
- Weed management in landscape beds.
Weeds are always a challenge and the approach can differ depending on whether the weed's life cycle is annual,
biennial, or perennial. For instance, perennial weeds can reproduce in four different ways: seed, roots, stems and/or stolons. However, as summer
ends, weeds with every lifespan tend to produce seed. Killing or removing weeds before they seed is critical for control. Weed in bed areas
either by spraying or by hand. If hand-weeding, it is easier when the soil is damp. See the link for detailed insturctions.
One year's seed
is seven years' weed.
Tips & Tasks
- Transplant broccoli, cabbage and cauliflower plants in mid-August.
- Plant beets, Chinese cabbage, cucumber, kale, kohlrabi, lettuce, mustard, radish, rutabaga, spinach, squash and turnip.
Vegetables need at least 1” of water each week to remain productive. In sandy soils apply 1/3” of water every third day to keep
the top 6–8” of soil moist. In clay soils, water once or twice a week. Water early in the morning. Watering late in the day
Pests & Problems
|Vegetable · herb||Monitor for:|
|Broccoli, cabbage, cauliflower||worms|
Avoid blossom end rot by keeping
soil consistently moist and not over-fertilizing.
|Basil||downy mildew Leaves will
look yellow and spores will be visible on the undersurface of the leaf. Flavored basils, such as lemon or cinnamon, are less susceptible. If you
confirm infestation, you can report your findings to
- Pinch back basil, catmint, catnip and lemon basil to prevent flowering and keep them bushy, but allow some basil plants to bloom to
attract bees. Sow a new crop each month to harvest leaves.
- Each time you need a few chives from the garden, cut generously to encourage new growth. Snip the extras into short segment, put them in
a plastic container and store in the freezer.
- Swallowtail butterfly larvae (caterpillars) love fennel, parsley, dill, rue, and composite flowers like Queen Anne's Lace. Plant extras so
that both you and the caterpillars can enjoy them. Add some joe-pye weed to feed the butterflies once they appear.