What can I do to control fire ants in my raised beds?
You can use a fire ant bait with the active ingredient Spinosad. Several companies manufacture it these days and you should be able to find a container of it in any decent garden center or garden department. Please note: pay attention to the label. You want a BAIT, and it will be labeled as such. It will be granulated. Spinosad is also used in other formulations (liquid, etc.) but that is not what you want.
Spinosad is approved for organic use. Just read and follow the directions. The last thing you want in your raised beds are fire ants.
Since Knowledge is Power having good, reliable information is always a good thing to seek. The Texas A & M Fire Ant Research project provides just that.
Here is a link that might be useful: Fire Ant Control
Chris...I should add that a trade name for Spinosad is 'Conserve', and you may find that term on a label rather than Spinosad (which is the active ingredient).
the big box stores stopped carrying conserve products in my area. I have been having to chase them out with soapy water with little results.
Chris, Spinosad is easily purchased on line. I find myself comparing prices and ordering more and more on line as gasoline prices rise. While you are waiting for delivery it's fresh orange juice for breakfast, then chop orange skins in the food processor and scatter these over the garden and mounds. This method does not kill but seems to encourage the ants to move on a bit to another area, hopefully out of your garden.
I am having the same problem. The little bastards moved in just a couple weeks after I put in the raised beds. Ugh, it gives me the creeps. I've been using the suggestions in Howard Garrett's book and so far nothing has worked. This is what I've tried:
1. Use a soil drench containing orange oil. This does kill the ants on contact, but it seems to have no residual effect. As in, the ants will mill about inches away from where I poured the orange oil acting not the least bit repelled. The orange oil will harm your plants so I don't want it too close to where things are already planted. It's a good thing to use on mounds, but unless you can manage to get the queen, it just kills some ants and the rest move a few inches away.
2. Spread dry molasses. Again, this is supposed to repel ants and has no effect whatsoever. The ants are very happy to remain in my comfy beds.
I've also heard beneficial nemotodes can help, but I haven't been able to find any. I placed an order for a spinosad based bait on Amazon today, as none of the stores in my area carried it. I hope the spinosad works.
Fire ants here in SC seem to be becoming gradually outcompeted by another ant (forget name) that while it is more of a pest in the sense of entering houses too at least does not bite.
There is however another tiny ant I am now seeing here that has a worse bite than a fire ant. Not worse when it bites, you can barely feel that, but it does not heal up and stop itching for many weeks and gets scabby first.
BTW: where fire ants formed large recognizable mounds I would push a stick down into the mound and pour in a little full-strength ammonia solution, then push the hole closed. The killing vapors would fill all the tunnels and chambers. Ammonia is a natural compound, though here made in a chemical plant of course. It will be later oxidized to nitrate by soil bacteria and just become a fertilizer.
This worked for me:
1) I dug out 2 shovel-fulls of dirt centered where the ants had set up camp in my bed. I flung the dirt ~15 feet away. Of course there were still zillions of ants crawling area in the corner of my raised bed.
2) I mixed 1 gallon of water with ~3 tablespoons of molasses and poured it all over the affected area.
3) I filled in the hole I had dug with compost.
I checked 24hrs later with a shovel...they seem to have gone bye-bye! It's only been one day. Not sure if they'll eventually try to return.