Ants

[ElieEstephane]

Has anyone had previous occurences of ants in their pots?
Ants seem to be showing a liking to my cactus pots recently (start or autumn) and im not comfortable with that. Is their presence harmful? And no they are not attracted the secretions from root mealybugs as im sure my plants are bug free.
So far i had a case were they were storing tons of eggs in a pot of mammillaria haageana in the shade where i physically removed them and flushed several times with water and another case whe1re a 2 inch clump of ants was hiding under and in a pot of espostoopsis in full sun from sunrise to sunset. Im talking about the small ants that around 2mm.
If they are harmful, can anyone suggest non chemical solutions? (although ant pesticide is readily available at my hands).
Thanks in advance.

[Marzhattan]

Hey Elieestephane, I also was having this problem about a month ago, something that I noticed was that they were nesting themselves only on my plants potted in plastic pots and so I resolved this by repotting most of my collection onto clay pots and they have stopped infiltrating my cacti. It got really bad to the point where I would tap the plastic pots and what seemed like hundreds of ants would come scattering out of their nest in my cacti, flushing them out didn't work because they would return by the end of the week.

[7george]

Yes, I have. When pots are close to the ant-house they would see potted or planted in the ground cacti like part of their environment. I found that putting saucers under pots make them put their eggs underneath and not to enter these pots or dig tunnels inside. I don't want to use insecticides against my ants. If needed I'd move or transplant cacti away.

[greenknight]

Moisture ants - there are a number of species. They are attracted to dampness, and when the surroundings become dry they move into your cactus pots. They'll move their whole colony when they find a better location within their range. When you dry out your cacti for the winter there's a good chance they'll move out.

I've had this (they're very common in this area, multiple species of them), they never persist in the cactus pots. They don't seem to harm adult cacti, but I did have them destroy a batch of seedlings. I protected my next planting by spreading flour around them, they won't crawl through dry powder - I imagine diatomaceous earth would be even more effective, or maybe red pepper.

As I said, they don't harm mature plants directly, but I have seen them farm aphids - they might do the same with mealy bugs. In any case, they're really, really annoying to have in your plant pots!

[DaveW]

Not had them in pots, but did have an ants nest under an Echinocereus in my greenhouse centre bed once. They kept on excavating soil and dumping it on top of the plant, semi-burying it. Also I suspected they kept nipping off any roots invading their tunnels therefore the plant just stagnated. When I moved the plant to a pot the plant grew again and flowered within a few months, plus I also cleared out the ants nest in the bed. They were also milking the nectar glands of a Ferocactus in the bed as well, plus had a trail along the wall and out through a tiny hole to get outside the greenhouse.

I would repot your affected plants and feed the ants eggs to the goldfish, then put down one of the commercially available ant killer products, or if none available locally see:-

http://tipnut.com/ant-killer/

Don't think we have moisture ants here since the UK is always wet therefore they don't need to search for moisture.

[ElieEstephane]

Thanks for all the replies!
I did apply some pesticide and most if not all ants disappeared. But we had some rain so i'll check later if i need to reapply pesticide.
Those ants are really annoying!

[FaeLLe]

You can also get ant nematodes, in the UK Green Gardener stocks them.