Ants tending aphids on Tomato plant
Too many ants! Plants are seriously damaged by their aphids. Production is stalled, plants die. Not ok.
Bad year! Ants are on beans, cucumbers, okra, even tomatoes! It’s become clear the usual hosing off the aphids isn’t enough. Hosing uses too much water, it waters your plants too much, which the ants like! With big tomato plants jammed in cages, you can’t get to the center and fuzzy plants don’t like to be watered on their leaves anyway. The aphids the ants tend are almost impossible to get off those fuzzy backed leaves – especially the stiff haired cucumber leaves. You can’t hard spray them off cucumber flowers because it blows the flowers away too. Argh.
Where do those aphids come from?! Some farming ant species gather and store the aphid eggs in their nests over the winter. In the spring, the ants carry the newly hatched aphids back to the plants. Queens that are leaving to start a new colony take an aphid egg to found a new herd of underground aphids in the new colony. As aphids feed, they often transmit plant viruses that can sometimes kill the plants, and the honeydew they make, that the ants feed on, favors the growth of sooty mold. This is a very destructive black fungus that spreads on plant leaves. Not only do ants protect and farm herds of aphids, but also cottony scales, mealybugs, soft-type scales, and whiteflies. Bad juju in the garden.
OK. So it’s either spray with a killer mix, or bait to end the colony. Enough already. Spraying is immediate; baiting takes a few days to a week. Do both to save your plants sooner.
- Insecticidal soaps are quick but temporary. Drench ant colonies with solutions of insecticidal soap, which are nearly non-toxic highly refined soap. It will not eliminate ants deep in the nest.
- Neem Oil, organic, is a maybe. Some report it works and swear by it, others say it doesn’t work at all. Probably depends on what kind of ants you have. Some say premix works for them, others say get the 100% stuff. It is not long lasting, repeated sprayings are needed.
- The Stinkies! Tea Tree Oil, herbs like Peppermint or Rosemary, Cinnamon, Eucalyptus sprays work and smell great! These can be used a couple of different ways. Crush the leaves, sprinkle on an ant line and they vanish. Or, use one cup of water to ¼ cup of peppermint or spearmint. Mix in your blender, strain into a handheld pump sprayer. Put it where you want it! Repeated sprayings needed. Some say you need less of Tea Tree and less frequent sprayings.
- Food Grade Diatomaceous Earth is fossilized remains of plankton; it looks like an off-white talc powder. It kills insects with exoskeletons, all kinds of them! It is perfectly safe for mammals, in fact, is eaten daily by some humans. To work it has to get ON the ant, and if it is even dew dampened, doesn’t work. It doesn’t attract ants, so they don’t invite their friends, and it isn’t ‘shared’ with the other ants. So yes it works, and no it doesn’t. If your plants are suffering now, it’s too slow to use.
- Vinegar A half to a liter down the hole kills, but the ones that escape merely move. Remember, vinegar is also an herbicide. Be careful.
- Water? Ants can live submerged in water for several days. That’s why the hose down the hole doesn’t work. So you need a little fire power, boiling hot water, to kill them.
‘Permanent’ Solution! Borax, plain old grocery store 20 Mule Team Borax kills the colony. It really works without fail. It’s cheap, a little goes a long way, and you can use what’s left to do your laundry!
Spray Mix 1/2 cup of sugar with 1 teaspoon of borax (20 mule team) with 1 cup of water to make a spray and spray on their trail where they enter the house (garden) and in 3 days they will be gone. Spay around the windows and doors to keep them out. When the spray dries they eat the crystals and take them back to the nest and POOF they are gone. At the garden, do this on a WINDLESS DAY, and be very careful not to get it on your plants. It’s an herbicide.
Per April Sanders, here’s how the BAIT thing works: Worker ants only feed on liquids. They take solid food back to the nests, where it is given to larvae. Then, the larvae convert it to liquid and feed it back to the worker ants [all the worker ants!]. Straight boric acid or insecticide will kill ants, but the worker ants will eat it rather than taking it back to the nest because it is in liquid form. Making a paste ensures the poison will get to the nest.
The first bait recipes I found were sugar and Borax. So I tried it. I found a lot of dead ants, meaning the Borax was not getting back to the nest, but the Borax was definitely killing the ants. After reading April’s explanation, I am now adding cornmeal to the mix. It is a ‘solid’ the ants have to carry back to the nest for processing. So sugar to attract the ants, cornmeal to carry home, Borax to do the job.
Here’s the skinny on cornmeal! Neither cornmeal nor grits cause ants to explode or jam up and starve because ants don’t eat solids. Cornmeal does disrupt ants’ scent trails until they lay down new ones. Yes, the ants might move, due to disrupted trails, and that might be only a few feet away. It appears to stop ants, but they are merely feeding close to their nest at your expense! They take the stuff home, let the larvae convert it to liquid, and they get it back in the form they can eat.
April explains that cornmeal is a medium to carry the poison. ‘Mix cornmeal with a slow-acting liquid insecticide or boric acid to make a paste. Slow-acting insecticides are the most effective way of controlling ants, according to the Colorado State University Extension. Choose one made specifically for ants for best results, and add it a little at a time to the cornmeal until you have a thick paste.’
- Sugar ants. Bait is serious. This means you are out to kill the colony, a ‘permanent fix.’ Bait is easy to make, a cup of very warm water, 1/2 c of sugar, cornmeal, 2 tablespoons Borax, make a paste. Set it out in a way birds, pets or children can’t get to it. Put it out AFTER you have watered, at the base of plants the ants and aphids are bothering. The ants will go for the sugar and lay off your plants. Scout ants take it home to the colony, and it is spread to all the ants. It isn’t an instant fix, but it works in a few days to a week. REMOVE while you water, replace afterwards.
- For grease or protein ants, Golden Harvest Organics bait: Mix three parts peanut butter with two parts jelly and add one tablespoon of boric acid per six ounces of mix. Add cornmeal for your solid. Place the bait on pieces of paper or stuff it into large straws (safer so birds won’t get into it,) and place it where you see ants foraging.
Make your own SAFE bait containers!
- Small diameters of pipe or unchewable tubing keeps bait safe from birds, pets and small animals. Swab the inside of the end of the tube with a Q-tip to be sure the paste is stuffed far enough away from the end of the tube for a small creature to reach. Place out of the sun, or make some shade for it, along the ant trail.
- Make holes in a jar lid, toward the center, so if it gets wet, falls over or you lay it on its side, your bait doesn’t ooze out. Put your bait in the jar, put the lid on tight. Lay it on its side, butt end facing the direction you water from, so if you accidentally water, the water doesn’t get inside. Lay it on its side along the ant trail, but especially near a plant the ants have been tending, for their easy access. They will go to it and stop tending the aphids. Don’t put it in full sun so it won’t bake your bait or be too hot for the ants to want to get into. If the lid surface is too slick for purchase, sandpaper or scratch it with a rock so the ants can get a grip. Containers are safe for you to handle when you want to move them or add more bait or remove while you water. If you make holes in the sides, make them high so the bait doesn’t seep out.
When I say Borax really works, I mean it! BE VERY CAREFUL. Besides a bugacide, it is an herbicide, used to kill weeds! It can’t tell the difference between a weed and your veggie plants. When you put down your bait, do not water later, forgetting it is there, and get it in your soil or on your plants. Take up your baits before you water. Definitely don’t do it before rains.
More ant & Borax details from an undated UCCE article on ‘New Research’ by Nick Savotich says: ‘The Argentine ant, being a honeydew feeder, has a strong preference for high carbohydrate liquids. High sucrose-based baits, (50% solution), were found to be the most preferred. Various concentrations of boric acid as the toxicant were also tried in combination with the high sucrose baits. It was found that the lowest concentration of boric acid, 0.25%, was as acceptable to the ants as was the sugar solution alone. Higher concentrations, 0.5 – 2%, tended to inhibit acceptance. Boric acid is an excellent toxicant for ants. However the next step is to determine whether this very low concentration (0.25%) is adequate to destroy whole colonies of the Argentine ant.’ So you see, it doesn’t take much of that 20 Mule Team to do the job.
For best results lay out a fresh bait daily. Lay it in areas where you see regular activity and near their points of entry if you know them. Don’t be diligent washing away their trails, you want them to find the bait spots easily again and again. All the workers in the colony can follow each others trails, so even if you killed off the first foragers, their partners will follow the trail they left.
Stop them before they start! Maybe you have been over watering? Ants make their colonies near a water source, and soft over watered plants are aphid friendly. When you find ant colony entrances, put a few drops of dish soap around, down the nest hole, fill in/bury the nest entrance. If they have taken up residence in your compost pile, turn that compost more frequently and water it a little less!
Predators! Groundbeetles, humpback flies, parasitic wasps, praying mantids and the yellow-shafted flicker all dine on ants. Plant flowering plants like cilantro, celery, carrots, food to bring the beneficial insect predators. You are lucky if you have woodpeckers because they are voracious ant eaters.
Wear gloves, wash your hands when you are done working with any toxic stuff, and remove your baits promptly when you are done with them.
Next year, put down your baits before you do plantings the ants and aphids love. Knock back the ant population from the get go! No, dear garden friends, we will never be ant free, nor do we want to be. Ants aerate our soil, clean up scraps and seeds, feed on fleas, termites, and other pests, are a food source for birds and other insects. As with all creatures, they play an important part in a healthy planet. Balance is a practical peace.