September Yard and Garden Tips

September 3, 2023

by Clemson Extension Laurens Office

September is here and there is hope for milder temps but there is much to do in the garden.

Watch out for:

Lawns

Lawn diseases – continue 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.
Spittle bugs – watch for spittlebugs in warm season lawns and on hollies. See Two-Lined Spittlebug 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 and Shrubs

Webworms – fall webworms should be appearing in pecan trees in mid- to late-August. Controlling the bottom 1/3 of the tree will be quite effective, even though we cannot reach the upper areas. Carbaryl (Sevin, etc.) is a good product for this. Observe all label precautions on mixing and use. Do not use dusts due to the problem with application – a spray made using the liquid form of the product will work fine. See Web-spinning Caterpillars for more information.

Vegetables

Blossom end rot – check your late 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 Tomatoes for more information.

Things to do:

Flowers

Bulbs – it’s almost time to buy your spring-flowering bulbs, such as daffodils, tulips, hyacinths, and crocus. Don’t plant them yet but wait for cooler weather. Store them in a cool place where temperatures will be 60 degrees F or lower. See Spring-Flowering Bulbsfor more information
Dividing – it’s time to divide spring and summer blooming perennials. See Dividing Perennials for more information.
Soil Test – now is the time to test the soil in your planned beds for plant nutrients. Soil tests usually take 10 days, so test now to have the results when you plant bulbs and beds. It is important to till in the lime needed (if any) for faster soil pH adjustment. You may also sample your vegetable garden now if you do not plan to add more fertilizer for late crops. See How to Collect a Soil Sample for information on sampling your areas.

Lawns

Fertilizer – it’s time for the second application of fertilizer for fescue and other cool-season grass lawns. Follow the recommendations on your soil test report for your lawn. DON’T fertilize warm-season grass lawns late in the fall! See Fertilizing Lawns for more information. If you have not soil-tested your lawn areas in the past 12 months, now is a great time!
Add Iron – applying iron to St. Augustine this month will provide dark green color without stimulating excessive growth. See Fertilizing Lawns for more information.
Aeration – fall is a great time to aerate cool season lawns such as fescue. Warm-season lawns (centipede, zoysia, Bermuda, St. Augustine) should be aerated in the spring and summer. See Aerating Lawns for more information.
Overseeding – many homeowners like to overseed their lawns with ryegrass for a green winter lawn. Mid-September is the best time to do this. See Overseeding with Ryegrassfor more information.
Lawn Establishment – if you plan to plant a cool-season (fescue) lawn, the best time to plant is between September 15 and October 15. Wait until next spring for warm-season grasses. Unhulled Bermuda seed can be planted now, but spring planting of hulled seed will provide a better stand. See Lawn Establishment for more information.
Henbit – this nice little lawn weed can be a problem. Treat now to prevent its return this summer. See Henbit 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 – as this month progresses you will probably need to cut back on your irrigation amounts. See the Home and Garden Center’s irrigation publications for more information. See How Much Water to determine how much water you are actually applying.

Ponds

Pond Stocking – September though January are good months to stock bream in a fishing pond. See Stocking & Harvesting Recreational Fish Ponds for more information.
Pond Liming – September though January are also good times to lime the pond bottom if necessary. See Liming Recreational Ponds for information on sampling the bottom and applying lime if needed.

Trees and Shrubs

Leaves – leaves are beginning to fall. If you have space and a little time composting is a great option; if not, you can also till them into any fallow beds you have or the vegetable garden. See Composting for more information.
Plan ahead – if you plan to plant some trees or shrubs this year, begin thinking about which plants you would like now, and find retailers that carry those varieties. You have plenty of time, but you certainly do not want to miss your favorite at the last minute.
Pecan Weevils – pecan weevils are those little critters that make holes in your pecans. Start treating for pecan weevils the first week of August, and continue treating once per week for 6 weeks. Place 5 ounces of liquid carbaryl (Sevin, etc.) in 10 gallons or more of water and spray the entire area under the tree, from trunk out to dripline. Repeat this for each tree. You will need to do this 2 years in a row to get rid of the pesky critters (they have a 2 year lifecycle). See Pecan Planting & Fertilization for more information.

Vegetables

Garden clean-up – half the tomato disease battle in a vegetable garden is sanitation. As tomatoes end their production remove them from the garden and take them to a landfill. Many diseases will over-winter on old infected leaves and stems. (A good practice for any plants you have had disease problems with this year).
Make a note – sketch out where you planted various vegetables in your garden. This will come in handy next spring when you plant, so you can rotate your crops to help prevent disease.
Vegetables – Some planting times for more common vegetables (See Planning a Garden for a full list and planting depths and spacings):
o Spinach – Sep. 15 – 30
o Turnips – Sept 1 – 15

All pamphlets referenced in this calendar may be found online:  http://www.clemson.edu/hgic or http://www.clemson.edu/cafls/departments/esps/factsheets/.

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.