Ants

Question from Robin:
ANTS, the demons on all levels. I told my husband our property would implode if the ants left. They completely destroyed my strawberry bed the year before no matter what I tried. Moved the bed and again within two months they destroyed the strawberry plants. They LOVE the plants, not the berries. Bought Grangettos Teal Baits…no use, tried cornmeal, Terro off to side of the beds etc. Have not tried your suggestion of worm castings. That will be my next ploy. Any additional thoughts?

Very much appreciated.

Answer from Pat:
Ants are indeed a huge problem in Southern California. They are very harmful in gardens because they carry with them all manner of pests, especially aphids which they milk for their honeydew. I have found that having a heavy population of beneficials such as birds and ladybugs and lacewings plus many other miniscule beneficial insects and arachnids will help keep aphids away, but they will not keep away the ants that bring the aphids.

Ants, especially Argentinian ants, are also most mysterious creatures. They disappear for months sometimes with no apparent reason and then suddenly reappear. This is said to be due to the temperature and other factors such as sources of food they either do or don’t like. But then here at my place for a year, ever since I put a heavy layer of mulch all over the ground in my garden I have had few ants in the garden and none in the house. That worries me. What if the mulch I used, which was delivered by truckload from a reputable company, actually contained pesticide residue from other properties? I do not allow any kind of spraying with chemicals on my property but what if the mulch contained some? On the other hand, if it was simply the oils in the woods and leaves that went into it then this could be a natural ant control.

Speaking of organic controls, wouldn’t it be nice if we could each have a pet anteater? Short of that I do indeed find that ants can be cut off at the pass by spreading a layer of dry bagged earthworm castings under the plants (as described in the section on citrus in the February chapter of my book and mentioned on other pages also. ) Make sure that the foliage, for example of a citrus tree, does not come down and brush the ground thus opening up another pathway for the ants to travel up onto the tree. Dry bagged earthworm castings worked so well for me that the results lasted for several years, especially around rose arbors where we spread a pretty heavy layer over the ground. For years ants shunned those arbors and stopped their little parade up the posts. The same worked for a reader who spread a hefty layer around a tropical passion fruit vine that was heavily infested with ants. Since then no problem.

On one occasion a friend of mine who had heard me talk about the corn meal solution lifted a rock in her garden and found a swarm of ants under it. These ants were swarming under the rock and up cracks in the concrete path right next to her swimming pool and were carrying eggs up from a wet spot down below. This is when she tried the cornmeal trick and by golly that time it worked for her. She took a handful of cornmeal and threw it onto the ants. They went crazy. The next day the cornmeal was all gone and so were the ants. I read somewhere that the ants carry it down into their burrows. We all know how cornmeal can get a fungus. It was said that a fungus grows on it down in the burrow and gives off a gas that kills the ants. I am hoping someone will do a study and find out if this is really true. But as of now I cannot find a scientific basis for any of this. The original source of this trick also stated that the ants ingest the cornmeal but we know that could not be so because cornmeal grains are too large. The ants cannot eat the cornmeal because it is too large for them, but perhaps they can eat a tiny bit of the oily substance or dust that sticks to the individual grains. I do not know this for sure.

My feeling is that this cornmeal trick is worth trying on swarms of ants but it definitely will not work on runs.

There is another factor adding to the mysterious and nefarious activities of ants and that is the time of year. As long as there are plenty of aphids making honeydew, scientific information seems to suggest that honeydew will be the only food the ants are going to eat. It has been discovered that at other times of year they will eat oils or meat, such as dead bugs, but this all depends on the time of year.