Sit around any table at a summer social gathering and the talk will eventually turn to fire ants. Everyone has their own idea about how to kill fire ants, including folk remedies and “common sense” ideas. Some of these remedies do kill some fire ants, but few of them have any real effect on the fire ant population in a yard. Many of them are illegal or even dangerous to attempt.
A number of these are listed in this article, with the reasons why they are not effective or good ideas.
1. Grits will kill fire ants. The idea behind this control is that fire ants will eat the grit pieces, which will then swell inside their stomachs and cause them to explode. This is completely false. Fire ants do not eat solid food, but instead transport it to their larvae and place it on a larva’s “lip.” The larva spits digestive juices on the food, breaking it down into a liquid form. The liquid food is them distributed to the entire colony. Sprinkling grits around fire ant mounds actually provides food for them.
2. Boiling water kills the mound. Boiling water will kill almost any insect it touches, including fire ants. There are two problems with this method, though. The first one is our inability to pour boiling water throughout the entire mound, killing all the queens and eggs. We may kill some of them, but we will not kill the mound. We will also kill all plants and microorganisms in the soil. The second problem is one of personal safety. Handling and transporting several gallons of boiling water to each mound is dangerous and can require a quick trip to the emergency room.
3. Gasoline or kerosene will kill them. Gasoline and kerosene will kill insects. There are three problems with this method. First, we have the same problem that we do with boiling water - we generally can’t get gasoline or kerosene into the entire mound. Second, it is illegal to pour fuels and solvents onto the ground due to groundwater contamination. Intentionally pouring gasoline or other chemicals on the ground is a criminal act in South Carolina and can result in fines of up to $10,000.00 per day. Also, every fire ant mound has a tunnel leading down to groundwater, so any product applied to a mound - including fuel - has a small but open channel directly to groundwater. This also applies to various other chemicals, including brake cleaners, bleach, household cleaners, and so forth. Fire ant baits and insecticides are tested with this in mind to make sure the groundwater is safe when they are properly applied. And third, fuels and solvents are dangerous to handle in this fashion, especially gasoline. The results can be catastrophic if someone that is smoking walks down-wind of a gasoline-treated mound, or if someone flips a cigarette butt onto a mound recently treated with solvent or kerosene.
4. You can drown them if you pour enough water on them. This is true, but the problem is once again making sure that the water saturates or floods the entire mound for a long enough time period to suffocate the fire ants. Add to this fact that many of the fire ants may be “flushed” out of the mound alive and well and you can see why this method is ineffective. (Fire ants will actually “raft” together during a flood, floating to dry ground.)
5. Soapy water will killthem. The idea behind this treatment is that the soap will break down the waxy coating on their bodies, which retains water among other things. The ants will then be unable to retain water so they will dry out and die. Yes, soapy water can cause problems for fire ants, but we will not get it into all the nooks and crannies of the mound. We also have to be careful with groundwater contamination. Some of the cleaning agents found in various detergents may include phosphorus, which is a great nutrient for landscape plants when applied in proper amounts, but whichalso will cause prolific weed growth in ponds and lakes.
6. Granular laundry detergents will kill them. This assumes that the fire ants will eat the laundry detergent. The fire ant can smell approximately 5,000 times better than humans, so they will not be tempted to eat those aromatic (or even low-fragrance) detergents. Adding water takes us back to the soapy water method, with the same problems.
The best control for fire ants is a properly applied bait or insecticide. Many of these products are relatively inexpensive (baits generally cost $40 per acre per year to apply) to use in the home landscape. All of them are much more effective, when properly applied, than the methods mentioned above and much safer. Be safe - follow label directions of your chosen product and use it only where specified by the label.
More fire ant information is available on the Clemson Home and Garden Information Center:
Home Lawn Fire Ant Control
https://hgic.clemson.edu/factsheet/fire-ant-management-in-the-home-lawn/
Home Garden Fire Ant Control
https://hgic.clemson.edu/factsheet/controlling-fire-ants-in-the-vegetable-garden/
May Yard and
Garden Tips
(http://www.clemson.edu/laurens)
Watch out for:
Flowers
•Japanese beetles - these pests will defoliate plants in short order. 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 dusts due to the problem with application - a spray made using the liquid form of the product will work fine. And spray after 5:00 pm 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
•Bag worms - bag worms can kill a tree if it is heavily infested. Inspect your trees periodically - bagworms seem to like juniper, arborvitae, and pines, but they are 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 week 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 the hulled seed at this time of year (you can seed with unhulled seed in the fall). 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. See the Home and Garden Center’s irrigation publications for more information, espcecially the publication on Irrigation Time of Day. Spring and fall are good times for disease to blossom, so do not allow your irrigation scheduling to increase these problems. 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, and see How Much Water to determine how much water you are actually applying, and Determining When to Irrigate to help determine when your plants need water. 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
•Vegetables - Some planting times for more common vegetables (See Planning a Garden for a full list and planting depths and spacings):
oCucumbers - Apr. 15 - May 15
oCantaloupes - Apr. 15 - May 15
oLima beans - May 1 - 15
oMelons - Apr. 20 - Jun. 30
oOkra - May 1 - 15
oPeppers - May 1 - 30
oSouthern peas - May 1 - June 30
oSweet potato - May 10 - June 10
oSquash - Apr. 15 - May 15
oTomato - May 1-30
All pamphlets referenced in this calendar may be found online: 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.
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.
