ants in my plants!

REMF33

So I finally got round to potting on my 20 year old (probably very stunted due to infrequent potting on) olive tree, and it turns out that it's an ant nest in disguise. The tree seems ok. But I don't think we can continue with this state of affairs...! Any suggestions?

Pete.8

The ants wont harm your olive as such, but the air pockets they create can damage the roots and prevent water getting to the roots.
Like you I also have an olive, mine has been in a big pot for about 15 years and it also has a major side-line in ant accommodation.
So long as the tree looks ok I leave them to it, but some years it gets bad and leaves begin to yellow.
I try and evict them by flooding the pot over and over. It sometimes works, but they seem to have their own drainage system set up and the water often just flows straight out of the bottom of the pot - which is also starving the roots of water.
As a last resort I have used ant powder which does get rid of them and doesn't seem to have harmed my tree. But they still come back eventually.

Seaweed extract is an excellent tonic for olives. Despite the colour, it's a mild fertilizer and contains lots of micro nutrients that are vital for plant health and will be missing from the compost of long term potted plants. I try and remember to give mine some about once every 6 weeks in the spring/summer.

I would think some fresh compost and a bigger pot is needed anyway, but the ants may well be back - and they will appreciate the extra space

BenDover

Did you have the pot sitting directly on the ground or on pot feet?  If it was directly on the ground then it makes it very easy for the ants to get into the pot from underneath.  In my experience, if pots and containers are raised off the ground, ants don't tend to take up residence.

REMF33

It is still sitting on the lawn, potless. Hopefully it will surivive the (warm) night, like this. Last time I looked, the ants seemed to have disappeared. Into inner chambers, or scarpered?
It was sitting on the ground/soil. I will see if I can find anything in the garden to raise it off the ground once it's been repotted.
I wondered about putting diatomaceous earth on the plant.
I have to say, although I was a little horrified when I discovered the ant colony (especially as I had been trying to get into the root system to tease a few out - to no avail - on the other side, before turning over and finding the ants), I also found it fascinating. I could see ants transporting grubs around the chambers.
I do seem to have a terrible ant problem this year, in general.

Butterfly66

Please re-pot is ASAP. Although a mild night, the plant will have been losing moisture constantly and roots aren’t designed to be exposed

REMF33

ok. Will do it shortly (was too late last night.) I hope I've not killed it off.

REMF33

Ok done. Will pot it on properly later. I may try some nemasys on it. It actually produced olives last year for the second time ever (in more than 20 years.)