Ant Problem - HELP!

Chandler, AZ(Zone 9b)

Hi all!
The past year has seen a significant increase in ants in my yard. These ants will devour cactus flower buds often before they open on any cactus close to the ground.
To make matters worse, if thrashers peck a chunk - even a small one - in the cactus itself, the ants come in and clean out the plant until it is nothing more than an otherwise healthy-seeming husk!
Tephrocactus are especially susceptible to the latter to the point that I can't keep any around for more than a year (seem to be popular targets of thrashers because of the lack of dense spination).

I've tried a couple varieties of ant stakes with only limited success.
I've also tried spraying the yard with insecticide that attaches to the hose that is supposed to kill them.

I guess it could be worse, but does anyone have anything in particular they find most effective?

The latest was my first bloom from my Coleocephalocereus aureus in the pictures. There is nothing left of the flower this morning but a nubbin (the photos were taken last night).


Thumbnail by Minime8484 Thumbnail by Minime8484
Prosper, TX(Zone 8a)

I use beneficial nematodes for any ant problems I have including the native and non native fire ants.

Mesa, AZ(Zone 9b)

Hi Tristan,

WOW, those are some voracious ants. Plenty of ants in the yard here, but I have not seen them do anything like that. They tend to go after me before they go after the cacti. They do seem to visit the extrafloral nectaries on the Ferocacti that I have growing. On the Ferocactus emoryi they started piling up sand on the crown of the cactus for a while. Not sure why, I kept washing it off and eventually they stopped doing it. You can see the sand on the attached picture.

Not sure I have anything really useful for you regarding the ants. Do you know where their nest is? I guess if you can get them there you might be able to get rid of them, otherwise they will likely keep coming back.
Because we rent the house we live in, we are obliged by our lease agreement to get the outside base of the house and the fence line sprayed by an exterminator once a year. That definitely cuts down on critters coming into the house, maybe it helps against new/different ants migrating into our yard too. I'd prefer not to have to do the spraying, since it does not really discriminate between the good and the bad bugs - though it seems to not affect the flying critters and is pet save in a few hours. However, we definitely noticed an increase in stuff making it into the house, the one time we were a few months late in getting it done.

Good luck finding a solution!



Thumbnail by mcvansoest
Prosper, TX(Zone 8a)

Simply the best methods for bad bug eradication is by a beneficial friendly product. Around here and I assume elsewhere 90% of exterminators use potentially toxic insecticides that unfortunately end up killing all or most of the natural beneficial predators to the pest insects. Where as believe it or not many pest insects and critters can and do buil up resistance to these insecticides there by making it more harmfully to the soil and water supply cause of the continual use and frequency to spray stronger and longer lasting insecticides. For my if it's not safe in the bottle then it's not safe in the ground cause what you use affects people a whole lot longer than what's at hand and usually ends up in our food and water supply.

Fountain Hills, AZ(Zone 9b)

I'd bet I have tens of millions of Argentine ants. They are everywhere in astounding numbers. They don't bother me or the pups or the plants, though I wonder if they farm aphids. I'm guessing not, since aphids may actually be larger than them. Ant control can be a tricky business, since some types of ants effectively control a wide variety of other garden insect pests.

Prosper, TX(Zone 8a)

Hey German I'll trade you for some of your Argentines if you'll take a million or so imported fire ants....Seems the only ants I have from Argentina are the rover ants and they are more fun to watch than eradicate. Here it's mostly fire ants which I despise no matter what and in ETX I had fungus ants which I like even less than fire ants. I target the destructive ones and do no harm to the semi beneficial ones unless they are in the ground with the grubs and fire ants.

Surely you folks in AZ have fire ants?

Fountain Hills, AZ(Zone 9b)

Yes, fire ants are around, my mother had to deal with them in Scottsdale. But they aren't out in the desert where I live, and I'm not complaining. As long as the Argentines stay out of my house, I'm happy to leave 'em be.

Prosper, TX(Zone 8a)

This isn't ant related but what type of soil and substrate do you have where you live German Star?

Baja California, Mexico(Zone 11)

We have ants all over the place here and I have found it impossible to control them in any long-term way. They are seasonal, so there's a brief break in the winter, maybe that's because of the rain. Inside the house we control them by putting out drops of boric-acid laced sugar water, which is pretty cheap and effective (and nontoxic). They carry off most of the corpses which is a bonus.

They do like to collect piles of dirt on top of the Ferocacti. Some times there's fruit in there, but other times it must be extrafloral nectar. I try to blow them off when I see that kind of action.

In general ants in the patio garden are the sentinels of new growth, flower buds, and plants in crisis because they see opportunities to farm sucking bugs in those situations. The ants aren't the killers, the mealies and aphids are. That means control is at best temporary (ants will return after a plant is squeaky clean) unless I introduce a systemic, which is my measure of last resort. So whenever I see an ant trail to a container, I try to figure out what they're doing and put an end to it. They can set up wall-to-wall scale on a flower bud within days.

There are just as many ants in the garden as on the patio, but the plants in the ground seem to benefit more from natural controls. I imagine there's quite a bit of predation out there. I see a good number of spiders nesting under the pots on the patio, which I take as a good sign. (Though the black widows and scorpions like the same places, so you have to look twice.)

Fountain Hills, AZ(Zone 9b)

Couldn't say, ground is hard as a rock, and requires a pickax to negotiate, and that's the good spots where there isn't much caliche. I still remember the very first plant/Agave I added to my landscape. I didn't have a clue what I was doing and actually tried to dig a 7-gal hole with a shovel -- hahaha!. It took me three hours and a fair quantity of spilled blood as I recall, some of which was spent attacking a caliche deposit with a hammer and chisel. I've since upped my game considerably in the yard tool department.

Mesa, AZ(Zone 9b)

Hello Minime. I've been able to keep the ants under control by using Andro. It looks a little like fine sawdust; you sprinkle it around where the ants are and they carry it back to the nest and it wipes out the entire colony. I've used this for years. As soon as I see and ant infestation I treat them to a helping of Andro. So far I have not seen and collateral damage to birds, pets, or skinks.

Prosper, TX(Zone 8a)

Caliche for you and limestone chalk for me.

Chandler, AZ(Zone 9b)

Quote from 48flash :
Hello Minime. I've been able to keep the ants under control by using Andro. It looks a little like fine sawdust; you sprinkle it around where the ants are and they carry it back to the nest and it wipes out the entire colony. I've used this for years. As soon as I see and ant infestation I treat them to a helping of Andro. So far I have not seen and collateral damage to birds, pets, or skinks.

I went ahead and tried far, it looks to be working. My in-ground Pereskia grandifolia, which can't manage to keep a leaf intact long before the ants chewed them up, seems to be getting new leaves that are undamaged, and I am not seeing as much ant activity as I had in the past.

Thanks for the suggestions - will post again with any progress (or lack thereof)!

Perth, United Kingdom(Zone 7b)

Sounds odd hearing of ants damaging cacti, I thought ants were largely beneficial to the nectar producing cacti that attract them. At least with Ferocactus, I thought the whole nectar producing thing was to attract ants that would in turn destroy damaging insects that threatened flower buds etc. Maybe they're alien species ants that don't behave as natives would?

Sun Lakes, AZ(Zone 9a)

Yes, DMersh, I have small brown ants all over my Ferocactus and they do no damage at all. My understanding is that they are beneficial as you said. I've seen Minime8484's plants and they are definitely eating the flowers so maybe it is a different type of ant--more like a black carpenter ant? I didn't actually see the ants in person. It does appear the Amdro that was suggested is working.

Baja California, Mexico(Zone 11)

The ants in my garden are not beneficial to any plants that I can tell. Maybe in the wild it's different. But here where there are ants, the sucking bugs are often soon to follow. Ferocacti included.

Sun Lakes, AZ(Zone 9a)

The little brown ants run all around my Ferocactus in the summer when they are active and the plants are in bloom. They definitely don't do any harm to them or the buds.

Baja California, Mexico(Zone 11)

After my F. latispinus developed scale secondary to an ant party on the crown, I became less inclined to view the ants as benign visitors.

Indian Harbour Beach, FL(Zone 10a)

Hope you have the ants under control .... If not, try cinnamon. Seriously, orchid growers use it all the time because of its antiseptic properties and sprinkle it on any pruning cuts ... Good for any plant and not just for orchids. I always keep a container handy (get it from the Dollar store), and have learned that it can be very helpful in keeping ants away from your potted plants -- they just don't like it.

San Marcos, TX(Zone 8b)

For fire ants here in Texas, we use a bait product called Amdro which targets the queen of the colony. Can't say for sure if it will work for Argentine ants. It's about as environmentally friendly a product as you can get, though since all that's required is to sprinkle some of it around the mound. The workers feed it to the queen and in a few days the mound is dead.

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