Coastal – Christopher Burtt
- Begin fertilizing lawns based on soil test results.
- With mower blades sharpened, mow the lawn at the appropriate height for the turf species.
- Look for thin areas in the lawn and plan to topdress with compost or re-sod.
- Turfgrass needs about 1-inch of rain a week. When irrigating the lawn, do it early in the morning, once or twice a week, to equal an inch total.
- Most shrubs should have been pruned by now, with a few exceptions. If any spring-flowering shrubs have not been pruned, such as azaleas, do so now. Deadheading is a great way to encourage annuals, perennials, and reblooming shrubs to continue producing new flowers.
- Plant warm-season vegetables and annuals, such as the heat-loving vegetables like okra, peppers, watermelons, and eggplant.
- Harvest any vegetables that are ready, such as onions, potatoes, or garlic.
- Now is the time to monitor the water needs of the garden. Keep in mind that annuals and vegetables (with smaller root systems) may need water daily depending on the plant. Water in the morning and avoid wetting the leaves to help mitigate disease spread.
- Scout plants often and consistently to stay on top of the infestations. Also, begin to watch for Japanese beetles as they will soon be emerging and wreaking havoc.
- Look for plant disease issues that may arise due to heat, humidity, and stress. Remember, prevention is key, and keeping plants healthy is the best form of prevention.
Midlands – Carmen Ketron
- Direct seed heat-loving vegetables, including okra, pole beans, and southern peas.
- Purchase and plant sweetpotato slips.
- Transplant out the last warm season transplants, including eggplant, peppers, and tomatoes.
- Fertilize your warm-season lawns such as centipedegrass, zoysiagrass, St. Augustinegrass, and bermudagrass, according to soil test results.
- Keep an eye out for weeds emerging in lawns. Identify the weeds and hand remove young ones.
- Late plantings of warm-season annuals can be planted in the ground or in containers. Coleus, zinnias, and flowering basils can all be planted to brighten up a garden bed.
- Source mulching material and apply after plantings have become established to conserve water and reduce weed pressure.
- Deadhead older flowers to encourage continued flowering through the season.
- Stop spraying your shrubs with pesticide emulsions like neem oil and horticultural oil when the temperatures reach above 85°
- Keep an eye out for scale insects in their crawler stage.
Upstate – Cory Tanner
- Prune azaleas and other spring-flowering shrubs as soon as possible after their flowers have faded since they bloom on last year’s growth. Finish pruning before the end of May.
- Harvest blueberries every 7 to 10 days. Utilize bird netting to protect ripening berries.
- The leaves of most spring bulbs may be removed once they have collapsed and turned brown.
- Fertilize warm-season lawns (bermudagrass, zoysiagrass, centipedegrass) according to soil test results, but do not fertilize cool-season lawns (tall fescue) during the summer.
- Vegetable gardens need at least one inch of water per week (either rainfall or irrigation) to guarantee good yields.
- Plant heat-loving vegetables such as tomatoes, okra, watermelon, sweetpotatoes, butterbeans, and southern peas.
- Don’t apply broadleaf herbicides on days of excessive heat (greater than 90 °F) or high wind speeds (greater than 10 mph) to limit volatilization (liquid transforming to gas form) and drift of herbicides, respectively. Otherwise, accidental damage to nearby vegetable and ornamental plants may occur.
If this document didn’t answer your questions, please contact HGIC at hgic@clemson.edu or 1-888-656-9988.
Original Author(s)
Christopher Burtt, Urban Hort. Agent, Charleston County, Clemson Extension
Carmen Ketron, Urban Horticulture Agent, Darlington County & Florence Master Gardener Coordinator, Cooperative Extension, Clemson University
Cory Tanner, Horticulture Program Team Director, Clemson University