Coastal Region – Brad Fowler
- Blossom end rot can be a major problem throughout the summer for tomatoes and squash. Provide adequate and consistent moisture to help mitigate the issue.
- Summer months, for individuals who have planted vegetables, means reaping the rewards of the hard work invested in planning and planting the garden. Don’t miss out on the best possible quality of those vegetables by harvesting them too early or too late.
Squash ready to be harvested.
Brad Fowler, ©2025, Clemson Extension
- While this might seem counterintuitive, be conservative when watering even as temperatures increase in June. Too much water can cause a variety of issues like brown patch and root disease in the lawn and ornamental plants.
- Certain lawn pests like fire ants and mole crickets may need to be managed during the summer. Be sure to identify insects properly before treatment and follow all label instructions when using pesticides.
Ground bee mounds may be mistake for mole crickets or other insect pests
Brad Fowler, ©2025, Clemson Extension
- While many indoor plants can be moved outside during the summer, they may be damaged if placed in direct sunlight.
- Use caution when trying to control weeds in the lawn this time of year. Turf may be damaged by herbicides when temperatures get above 85 °F. Additionally, herbicides do not need to be applied to turf that is under drought stress. Be sure to follow all label instructions.
Be cautious when treating weeds like clover in the lawn during the summer.
Brad Fowler, ©2025, Clemson Extension
Midlands Region – Jennifer Weaver
Watering Trees and Shrubs in the Landscape
- If you plant container grown and balled and burlapped (B&B) trees and shrubs, make sure you will be able to water them on a regular basis. Keep them moist (not saturated) until they become established, meaning they can survive on their own without supplemental water. Depending on size, this can take 1-2 full growing seasons.
- Generally, the safest and most effective approach is to irrigate regularly by slowly dripping a known quantity of water into the root ball of the plant.
- Water should be distributed evenly over the root ball. Apply within the plant’s dripline (outer edge of the leaf canopy).
- Avoid spraying onto the trunk or canopy of a tree. Select heads that minimize water spraying onto the leaves of shrubs to reduce the chances of fungal or bacterial disease.
- Be careful not to overwater, and apply the water only as fast as the soil can absorb it.
- Group plants with similar water requirements. If you match plants with their preferred growing conditions, they will require less water, fertilizer, pesticides and maintenance when compared to plants growing in the wrong location.
- Established plants need less irrigation than growing turf.
- Turf and landscape plants should be on different irrigation zones.
- Plant drought-tolerant species to reduce water usage, especially natives!
Make sure your irrigation heads are positioned to water the intended plants
and not something else (like a tree trunk).
Photo credit: UF/IFAS. 2024.
Snails and Slugs
Snails and slugs are present in the garden from spring to fall in cool, moist areas with shade and can be very destructive.
- They damage plants by creating irregular holes on leaves, flowers and fruit by scraping and chewing with their rasp-like tongues. Small succulent plant parts can be easily clipped by snail and slug feeding.
- Snails and slugs use slime they produce to glide along on a muscular foot. Look for silvery mucous trails to confirm that slugs or snails are the culprits, as their damage is similar to feeding by other pests such as earwigs, caterpillars and other chewing insects.
- Use a variety of steps to reduce their numbers if slugs and snails are a problem in your garden.
Slugs can cause serious damage to the foliage of hosta and many other low-growing annuals and perennials.
Joey Williamson, ©2019 HGIC, Clemson Extension
Summer and Fall Flowering Bulbs
Summer and fall flowering bulbs (some are classified as rhizomes, corms and tubers) such as gladiolus, agapanthus, dahlia, colchicum (autumn crocus), lycoris, lily and spider lily can be planted now.
- The bloom from June to September.
- There are options for both sun and shade, so choose accordingly.
- Colchicums are sometimes called “naked ladies” because the flowers appear without foliage in the fall. Their foliage, which is produced in the spring, dies back with the summer heat, leaving the flowers to bloom “naked” of leaves.
Deadhead and fertilize summer annuals regularly to keep them blooming.
When cutting rose flowers, remember to let 2, five-leaf leaflets remain on the growing stem. New shoots that develop from three-leaf leaflets are less likely to bloom. Because a new shoot will develop from the base of that leaf, be sure the bud is facing outward to keep the center of the plant open for good air circulation.
Autumn crocus, (Colchicum autumnal).
Image credit: Pixabay.com
Ornamental onions (Allium Spp.) are grown from bulbs planted in the fall.
Photo credit: C. Carignan, UME. 2023
Upstate Region- LayLa Burgess
- There is still time to direct-seed annuals like cosmos, zinnia, cleome, marigolds, and sunflowers for a late summer bloom. Ensure blooms until frost by staggering sunflower seed plantings a week or two apart. Direct seed perennials like coneflower, coreopsis, and goldenrods to extend the bloom into the fall.
Sunflowers provide nectar and pollen from summer to late fall.
LayLa Burgess, ©2017, Clemson Extension
- Gardeners can still plant dahlia tubers for a fall bloom. Set dahlias at a depth of 6 to 8 inches with a 3 to 4-foot spacing. Collect & save dahlia seeds in the fall.
- Tomato and pepper transplants may still be available for succession planting. Direct sow seeds for another round of summer crops, including beans, squash, southern peas, cucumbers, and okra. Plant pumpkin seeds in anticipation of celebrating a Fall harvest. Garden math: Most pumpkins mature between 85 and 125 days (read seed packet information). Determine when to plant pumpkin seeds by counting the days between planting and harvest to coincide with Halloween. Pumpkins are shelf-stable through Thanksgiving or later. Plan to preserve your pumpkin or make a pie.
Pumpkin carving is an exciting, family-fun activity during Halloween and Thanksgiving.
LayLa Burgess, ©2024, Clemson Extension
- Time to give those herbs a haircut. Prune the tips of herbs to encourage branching. Limit flowers by pruning to preserve the flavor of the leaves.
Dill (Anethum graveolens) has a beautiful, feathery leaf texture.
LayLa Burgess, ©2025, Clemson Extension
- If the thatch layer in your warm-season lawn measures more than half an inch, it may be time to dethatch. Dethatch the lawn with a vertical mower. Then mow over the turfgrass to remove the remaining debris and follow up with adequate irrigation.
- Root semi-hardwood cuttings of your favorite broadleaf, evergreen shrubs like camellias, azaleas, tea olives, magnolias, and banana shrubs now. Choose pliable new green growth that has begun to harden and turn brown to propagate.
- Continue to water recently planted trees to help plants survive the upcoming heat and drought of July & August. Apply a fresh layer of compost or mulch, no more than 2 to 4 inches deep, around the base of tree trunks to help conserve soil moisture during the hot summer months. Keep mulch 4 to 6 inches from the trunk base, with the mulch ring extending as far as the drip line for maximum tree protection and health.
- June is a great month to visit one of your favorite specialty gardens or a sustainable landscape demonstration garden while plants are fresh and vibrant.
Enjoy exploring the outdoors.
LayLa Burgess, ©2025, Clemson Extension
