Fire Ants in Mulch

Hi all, my mini orchard is newly established (1yr4mos old) and I’m trying to figure out the cause of death of my Methley plum tree. The Scarlet Beauty 10’ away from it is doing great, but the Methley did not survive.

When about to dig it up, I noticed a ton of fire ants in the mulch around the tree. Could the ants have killed the tree? Should I avoid planting a new tree in the same area with all these ants? Is there a safe way to kill the ants and still be able to plant here soon to avoid an awkward gap in the middle of my row of trees?

Here’s a picture of the base of the tree if it helps:

I also have a fig tree with a ton of fire ants in the mulch as well (they are endemic all over my yard), and the whole main trunk seems dead (brown when I scratch it), however it’s growing new green shoots from the base. I thought this was indicative of frost damage, but could this be from the ants too?

Do you have rabbits in the area? Will it be possible a rabbit damage? Iknow my rabbits stripped /filed my plum/fig tree to the ground

Fire ants can kill a young tree. You need to come up with a plan to control them in your yard. They will be an ongoing problem.

I have fire ants here… in my compost pile… and they often get in the beds I make for raspberries, blackberries, fruit trees… Never had any of those die.

If you will mess with them every day for about a week… they will relocate somewhere else… perhaps somewhere you can poison and kill them.

I had a nest in with my illini black berry row last year… but they were not right in the middle at the base of any canes… more on the outer edge of the mulched area. I left them alone… nothing was harmed.
Blackberries produced well, and after fruiting, produced really nice primocanes.

Hate them… but they are here … but I have never had a fruit tree, berry bush, cane fruit that actually died because the planting hole or bed was infested with fire ants.

Good Luck

PS. found this online…

Why Fire Ants Nest Near Trees

Fire ants like to nest near trees because the soil is not disturbed by foot traffic or mowing. Ants need soil that is likely to be undisturbed in order for the colony to thrive. The tree also gives them a source of food and water because they will prey on other insects that could harm your trees.

Adult Trees

Fire ants pose no danger to trees that are well planted and matured. These trees have solid root systems that are not likely to be disturbed by the fire ants. In fact, the fire ants may help your trees to thrive because they will eat other insects that damage your trees or their roots.

New Trees

New trees or saplings should be protected from fire ants. These trees do not have solid root systems yet. This means that the fire ants could expose roots and allow them to dry out in their attempt to churn the soil for their colony. If you have new trees with fire ants nesting nearby, you will need to address the fire ant problem promptly to protect your tree.

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Sounds like they could be a problem for young newly planted tree if the planting hole is infested.
I have never had that problem here…

Here’s three Fire Ant pesticides registered for use in FL. All contain Pyriproxyfen.

Distance® Fire Ant Bait
Esteem® Fire Ant Bait (approved for range land)
Reemit™ Fire Ant Bait

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I poked around a bit more and discovered the fire ants were almost entirely in the mulch and none in the soil at all.

However, I did discover what I think the problem actually was:

The 1/4” drip ring that I had around the tree broke off of the 1/2” mainline, so every time the irrigation turned on, that tree was getting flooded with way more water than it needed :person_facepalming:. Will have to make sure I do more regular drip line maintenance checks at each of my trees from now on.

It was enough water to even saturate my half sandy Florida soil, so I’m betting the tree roots were so waterlogged they weren’t getting any oxygen at all.

Gonna remove the mulch from that area so it dries out a bit and repair the drip line before I plant anything else there.