This Month in Your Garden- August 2024

Coastal Region- Brad Fowler

• Make sure to scout the lawn regularly for pests. Armyworms and brown patch/large patch are a couple of common issues that can cause major damage if not treated quickly.
• Final applications of turf fertilizer should be complete before the end of August. Make sure fertilize based on a soil test and the specific needs of the turf.
• While it may be hot, it is still important to be conservative when watering. Many plants that can be grown in South Carolina are adapted to hot and dry conditions.
• Start planning for the fall by conducting a site analysis to determine any gaps in the landscape that may need to be filled in. It is important to get a plan together early so that desired plants can be sourced before the desired planting date.
• Pole beans, eggplants, and kale are just a few vegetables that can be planted in August to be harvested in the fall.
• A final planting of fast-growing annuals like zinnias can provide some nice color in the landscape going into fall.
• Baits applied at the end of August are a great way to control fire ants throughout the fall.
• Stay cool and enjoy the last few weeks of summer plantings while preparing the landscape and garden for the fall.

Peas planted for the fall garden.
Brad Fowler, ©2024, Clemson Extension

Always keep an eye on turf for insect and/or fungal damage.
Brad Fowler, ©2024, Clemson Extension

Midlands Region- Jennifer Weaver

August Garden Color

All Natives!

• • Loblolly bay (Gordonia lisianthus) is an evergreen tree with fragrant, camellia-like flowers, although hard to find commercially.
  • Sourwood (Oxydendron arboreum) blooms from June through August.
  • Summersweet clethra (Clethra alnifolia) flowers have a spicy fragrance.
  • Wild indigo (Baptisia spp.) blue false indigo and yellow wild indigo were used by Native Americans and settlers to produce a blue dye.
  • American beautyberry (Callicarpa americana) clusters of berries are a food source for many songbirds.
  • Smooth hydrangea (Hydrangea arborescens) and oakleaf (Hydrangea quercifolia) have beautiful white blooms.
  • Buttonbush (Cephalanthus occidentalis) flowers from June through August.
  • Seaside goldenrod (Solidago sempervirens) is often found near beaches and salt marshes.

Other Non-natives

• Common crape myrtle (Lagerstroemia indica). Crape myrtles are available in many different sizes. Choose a variety that fits your landscape and can grow to its full height without the need to prune it regularly.
• Rose of Sharon or althea (Hibiscus syriacus)
• Butterfly bush (Buddleia davidii)
• Blue mist shrub or caryopteris (Caryopteris x clandonensis)
• Spotlight on tree problems in the landscape – Water – too much or too little this summer?
  • What causes stress in trees?
    • The most common causes are drought, overcrowding and damage to the trunk or roots.
    • Drought weakens the defense mechanism of the tree. It can reduce the ability of the tree to isolate infection and prevent spread throughout the tree.
      • This can occur from
        • root damage during construction
        • lack of rainfall
        • overcrowding
    • Trunk damage invites infection by creating points of entry for pathogens. Keep string trimmers away from tree trunks!
    • Root damage also creates entry points for pathogens and reduces the tree’s ability to absorb water putting the tree under stress which makes the tree more susceptible to infection.
    • Provide good tree management practices to reduce drought stress and mechanical damage.
  • Foliage Diseases in Trees
    • Many of the common foliar diseases are fungal. Some can be lethal, while most are merely unsightly. Careful attention must be paid to disease identification before administering any control treatment.
    • Chemical injury can also mimic some of these diseases, so ask if herbicides have been used in the vicinity of the tree.
    • Protective control measures are not generally warranted for most leaf spots unless the health of the tree is in danger. Usually little can be done except to rake and destroy leaves in the fall to prevent a source for next year’s infection.
• BENEFICIALS – DID YOU KNOW? Syrphid flies, commonly known as hover flies, sport bodies often marked with brightly colored yellow stripes. Because of this, they are commonly mistaken for wasps or bees. This resemblance is a form of mimicry – mimicking the appearance of an insect that delivers a sting – to ward off predators. Even hover flies appear similar to bees and wasps, they are harmless as they are flies and do not have a stinger.
  • The larval stage is carnivorous feeding on a variety of things such as aphids, caterpillars, thrips, mealybugs and leafhoppers.
  • The adult stage is nectarivorous consuming honeydew, nectar and pollen.
  • Hover flies are considered a biocontrol agent or a beneficial insect to farmers and gardeners because they can potentially reduce the severity of pest outbreaks.
  • When hover flies are abundant they may reduce aphid populations by 70-100% therefore greatly reducing damage to plants.
  • Preserve hover flies by providing adequate sources of nectar and pollen and even overwintering habitat since most overwinter in leaf litter. Also, consider restricting the use of herbicides as they can reduce the floral and nectar sources which are key to the hover fly survival.
  • Hover flies are active year-round in warmer southern climates.
• Pruning in late summer and fall – prune out dead, diseased or broken wood but don’t do any major pruning.

Hover fly larva on strawberry leaf.
Tom Bilbo, ©2024, Clemson Extension

Adult hover flies are one of many pollinators that feed on nectar and pollen. They live 3 to 4 weeks.
Paul Thompson, ©2022, Clemson Extension

Upstate Region – Ginger Long

The Upstate region and all of South Carolina are in a state of drought, according to the National Integrated Drought Information System website drought.gov. Some areas in the Upstate are in a moderate to severe drought.

During a drought, water lawns with one inch of water per week. If you have an irrigation system, adjust the sprinkler heads so they are not watering the driveway, sidewalks, or the street to conserve water.

Trees, shrubs, and perennials should be watered in the early morning when the temperatures are cooler and there is less evaporation. To conserve water, consider installing soaker hoses or a drip irrigation system in landscaped areas.

Evergreens such as Leyland cypress and arborvitae are sensitive to drought, and needles can turn brown. Be sure to water consistently.

Mulch helps conserve moisture in the soil. It also keeps the soil temperature cooler in the summer. Add 2 inches of mulch around trees, shrubs, and in landscape beds.

Fertilizer that contains nitrogen should not be applied to warm-season lawns any later than August 15, which is two months before the average last frost date. This includes fertilizers marketed as winterizers.

Annual summer flowers will continue to bloom with regular watering and fertilizing. Cut back leggy stems and remove old flowers to encourage more blooms.

Plant marigolds and mums for fall blooms. Marigolds bloom until frost, longer than most mums.

African marigold Antigua™ Yellow (Tagetes erecta) bloom until frost.
Ginger E. Long, ©2024 HGIC, Clemson Extension

There are many perennials that bloom in August. Add Turk’s cap, toad lily, cardinal flowers, and Japanese anemones to shady areas. Add asters, salvias, Joe pye weed, and black-eyed Susans to sunny areas.

Toad Lily (Tricyrtis hirta) is a shade perennial that blooms in August.
Ginger E. Long, ©2024 HGIC, Clemson Extension

Black-eyed Susan (Rudbeckia ‘American Gold Rush’) grows in part shade to sun.
Ginger E. Long, ©2024 HGIC, Clemson Extension

In the vegetable garden, set out transplants of broccoli, cabbage, and cauliflower. Sow seeds for beets, Brussels sprouts, carrots, collards, cucumber, kale, mustard, peas, radish, spinach, summer squash, and turnips.

Georgia Southern Collards are an heirloom variety.
Barbara H. Smith, ©2023 HGIC, Clemson Extension

Georgia Southern Collards are an heirloom variety.
Barbara H. Smith, ©2023 HGIC, Clemson Extension

Set out broccoli transplants in August.
Barbara H. Smith, ©2023 HGIC, Clemson Extension

Plant crimson clover seeds in August so it has time to establish before the first freeze. It will bloom next spring. Cut it and allow it to decompose for green manure.

Sow crimson clover seeds in August for a colorful display next spring.
Barbara H. Smith, ©2019 HGIC, Clemson Extension

Look for crimson clover seeds that have been pre inoculated with a rhizobacteria coating.
Barbara H. Smith, ©2019 HGIC, Clemson Extension