Provided by the Clemson University Cooperative Extension Service
(http://www.clemson.edu/laurens)
Watch Out For
Flowers
Japanese Beetles
These pests will defoliate plants in short order, so 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 dust due to application issues; a spray made with the liquid form of the product will work fine. Spray after 5:00 p.m. to help protect our honeybee population.
Fruits
Fireblight
Inspect fruit trees for fireblight. If you had problems with fireblight last year, you will need to spray your blooms this year to prevent the spread. The best defense is a fireblight-resistant variety. See Fireblight for more information.
Lawns
Lawn Diseases
It’s time to begin watching for problems with brown patch and dollar spot in warm-season grasses, especially if you had problems with one of them last year. See Brown Patch Disease of Lawns and Leaf Diseases of Lawns for more information.
Chinch Bugs
Watch for chinch bugs in your warm-season lawn. See Chinch Bugs for more information.
White Grubs
The bacteria Bacillus thuringiensis does a nice job on Japanese beetle grubs, but it does take a little time to build up in the soil. Bacillus thuringiensis does not, however, control other types of grubs. See White Grub Management in Turfgrass for more information.
Trees
Bagworms
Bagworms can kill a tree if it is heavily infested. Inspect your trees periodically. Bagworms seem to like 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 will also take care of the problem. See Integrated Pest Management (I.P.M.) for Evergreen Bagworms for more information.
Oakworms
Oakworms and canker worms may appear in the spring and defoliate oak trees. This will not kill the trees, but it will add some stress to them. The trees will develop more leaves. The chemical carbaryl (Sevin, etc.) will kill the worms, but treatment of a large tree is not practical nor safe and therefore is not recommended. However, if you have a small oak tree (less than 10 feet tall) infested with them that can be safely sprayed, an application of this insecticide will control them. The bacterium Bacillus thuringiensis (Dipel, etc.) will also control oakworms and will not affect predatory insects. See Oak Diseases and Pests for more information.
Vegetables
Garden Insects
Keep an eye out for corn earworm, cucumber beetle, and squash vine borer in the garden. See Insect Pests of Sweet Corn and Cucumber, Squash, Melon & Other Cucurbit Insect Pests for more information.
Blossom End Rot
Check your tomatoes for blossom end rot on the fruit as it begins to form. This is usually an indication of a calcium deficiency. Place a handful of gypsum (land plaster) in the soil beside the tomato at planting (or later) to prevent this. Foliar sprays such as blossom end rot spray will also help alleviate the problem. Nothing will “heal” the fruit with rot on it, so remove and discard them. See Tomato for more information.
Things To Do
Flowers
Bulbs
You should be planting your summer- and fall-flowering bulbs in April and May, such as dahlias, gladioli, cannas, and lilies. Be sure to plant after the soil temperature reaches 55 degrees F. See Summer- and Fall-Flowering Bulbs for more information.
Fruits
Spray Fruit Trees
Continue spraying your fruit trees with a fungicide (Captan, etc.) every 7 to 10 days to provide the beautiful fruit you look forward to. Do not use any insecticides on the trees until less than 10% of the blooms remain — you certainly do not want to hurt your bee pollinators. The fungicide will have no effect on them.
Lawns
Lawn Fertilizer
You should apply a complete fertilizer to your warm-season lawn this month. See Fertilizing Lawns for more information.
Fire Ants
If you broadcast baits, apply your first treatment during the last week of April or the first few weeks of May. Be sure to apply fresh bait, and do it at the correct time of day. Fire ants only forage actively when the ground temperature is between 70 and 95 degrees F. See Fire Ant Management in the Home Lawn for more information.
Lawn Aeration
Any time your warm-season lawn is actively growing is a good time to aerate. David Parker relates that you should “aerate as long as you can stand it, then go over the yard once more.” See Aerating Lawns for more information.
Lawn Establishment
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. If you are planting Bermuda by seed, use hulled seed at this time of year. Wait until next fall for cool-season grasses (fescue). See Lawn Establishment for more information.
Nutsedge or “Nutgrass”
Nutsedge is very difficult to control. There are two main types in our area — purple and yellow. You must identify which you have before you begin treatment. Herbicides must be applied when the nutsedge is actively growing, which means decent soil moisture and warm conditions. See Nutsedge for more information.
Irrigation
You may be irrigating late this month if we have a dry spring. One inch per week is the appropriate amount for most lawns and vegetables (except sweet corn and yellow squash, which may require up to two inches depending on growth stage). Include rainfall in this amount. Do not irrigate every day. There are a few exceptions to this rule, such as potted plants, but only a few.
Ponds
Pond Stocking
May, June, and July are good months to stock bass in a fishing pond. See Stocking & Harvesting Recreational Fish Ponds for more information.
Vegetables
Planting Times for Common Vegetables
| Vegetable | Planting Dates |
|---|---|
| Cucumbers | Apr. 15 – May 15 |
| Cantaloupes | Apr. 15 – May 15 |
| Lima Beans | May 1 – 15 |
| Melons | Apr. 20 – Jun. 30 |
| Okra | May 1 – 15 |
| Peppers | May 1 – 30 |
| Southern Peas | May 1 – Jun. 30 |
| Sweet Potatoes | May 10 – Jun. 10 |
| Squash | Apr. 15 – May 15 |
| Tomatoes | May 1 – 30 |
See Planning a Garden for a full list and planting depths and spacings.
All pamphlets referenced in this calendar may be found online at:
http://www.clemson.edu/hgic
The Clemson University Cooperative Extension Service offers its programs to people of all ages, regardless of race, color, gender, religion, national origin, disability, political beliefs, sexual orientation, gender identity, marital or family status and is an equal opportunity employer.
