
While ants can usually become an unwanted plague in the house, they are useful in gardens. They represent an important part of the ecosystem. As a rule, they cause maximum damage to young plants/trees. However, it usually leads them to fruit trees for a less than acceptable reason, requiring swift action to protect the trees and fruit. The plant advisor reveals what needs to be done, when and why.
ant infestation
cause of an ant infestation
If the Formicidae running around in the garden, this does not usually bother hobby gardeners or garden owners - usually the opposite is the case. They distribute seeds in nature, keep various pests out of the gardens and aerate the soil. But when they climb a fruit tree en masse, aphids and/or psyllids are usually behind them. Unless they are on fruit trees, an ant migration on trees does not normally take place. Aphids and fleas, which suck the sap from fruit tree leaves, are excellent sources of carbohydrates for the Formicidae.
aphids
Aphids as donors for ant food
Ant colonies select trees on which there are many aphids/fleas. The reason is that they get their food from them. To do this, they “milk” them aphids and leaf fleas nearly. They love the sweet juice that the lice and fleas ingest by sucking on the leaves.

This preference for the sweet juice and thus also for the aphids and fleas goes so far that they transport aphids that have fallen down back up the trees. It is often the hard-working insects that bring the lice onto a fruit tree on purpose. They even offer them protection from their predators. It is important to them that they are/stay in large numbers on a fruit tree so that their entire colony can find a delicacy in them.
Preferred fruit trees
In principle, all types of fruit trees can be infested by ants if aphids or fleas can provide them with food. But especially that cherry tree with sweet cherries is endangered. If there are aphids in the vicinity, the hard-working insects prefer to settle them on a cherry tree, even if an apple tree is closer. This is explained by the particularly sweet leaves and flowers that a cherry tree has. Following this, the pear tree before the apple tree its position on the list of preferred fruit trees. They are also very fond of infesting orange tree, which spend the summer in pots on the terrace.
tree damage
Old fruit trees
In the case of old fruit trees that are ten or more years old, tree damage is generally not to be expected. However, it depends on how big the colony is and where it accumulates. They usually move around the tree trunk. Here they dig tunnels in the ground and, in the worst case, can expose the roots. As a result, the supply of nutrients could be disrupted and the fruit tree damaged accordingly. However, dying off is hardly to be expected in the case of old, large trees with a strong, extensive root system.

Young fruit trees
The situation is different for young fruit trees with still tender roots and sparse foliage. The aphid infestation can lead to leaf curling and wilting. The tree is weakened as it grows, which has a negative impact on the next blossom and the fruit stock, especially on a cherry tree. In the worst case, the tree can also die because the aphids deprive it of all energy and/or insufficient energy can be absorbed through the construction of the earth tunnel and exposed roots.
fruit damage
You don't have to worry about the fruit on a cherry tree or other fruit trees, because ants only nibble on the surface of the fruit. The aphids/fleas are limited to the leaf sap. When you harvest fruit, it should always be washed. In this way, the hard-working insects are washed away. The fruit remains fully consumable.
combat
When to react to an ant infestation?
In general, larger ant colonies should be freed from young easter trees to prevent damage. In the case of older specimens, intervention is only necessary in exceptional situations.
These are given if, for example:
- the cavity created by the tunnel construction poses a risk of injury, such as twisting the foot
- the tree is weakened for other reasons
- the ants overflow to adjacent usable areas and cause a disturbance there, such as terraces or sandpits
- unexpected damage to the tree and/or flowering/fruit formation decreases
There are several ways to get rid of ants on a fruit tree and fight them permanently.

insecticides
Insecticides are available in specialist shops that kill ants and aphids as well as fleas. This measure is not advisable, because it interferes with the ecosystem in your garden. If you use a chemical preparation, the harvest is at the same time or no longer safe to eat.
Boiling water
Basically, the starting point of a fight is always the anthill, which is located in root or near the fruit trees. In rare cases, an anthill can also occur on the tree trunk or in branches. Dousing the burrow with boiling water is effective, but only advisable if the burrow is farther from the trunk, otherwise tree roots could be damaged.
Since not all the ants are in the burrow, repeated watering over a few days is necessary to be able to combat all the ants. At the same time, the aphids / fleas must be combated so that they do not attract new ant colonies.
ant bait
Special ant baits usually contain toxic insecticides that kill the crawling insects. by certain attractants they are lured into cans where they ingest the poison. There are different modes of action. Some work immediately and others only after a few hours. In the latter case, the ingested poison can also be passed on to the offspring. The ant baits should be placed close to the affected tree and out of the reach of small children and pets. To be effective, they need to be placed around the fruit trees for a few weeks.
relocate ants
Because they are farm animals and valuable for nature, resettlement is recommended instead of fighting them.
duct tape
Wrap double-sided tape around the bottom of the trunk so that it completely breaks through the ant trail and there is no other way out than via the tape. Some ants will venture onto the tape and stick. Most will relocate as the tape breaks the "scent trail".

chalk
Using circles works similar to double-sided tape. Draw a strong chalk line around the trunk as densely as possible. This irritates the ants, takes away their scent trail and causes them to move.
fragrances
You have to have a little patience when driving them away by laying out certain scents on the tree. They work best when laid out on the ground around the tree trunk. The more intense the scent, the faster the ants will be driven away. For this reason, you should change the scent source at least once a day - better in the morning and in the evening, so that the scent intensity is kept high and the Formicidae retreat.
The most suitable fragrance dispensers include:
- Essential Oils
- vinegar
- lavender
- onions
- garlic
- cinnamon powder
- lemon peels
- thyme
- marjoram
- wood wool

The most environmentally friendly and animal-friendly way of relocating is to use wood shavings to do it yourself.
Proceed as follows:
- Fill the clay pot with wood shavings
- place it face down on the ant trail
- the ants will see the wood shavings as a new burrow and move there
- after the “move” is complete, without turning it over, pick up the pot with a shovel
- Set the pot down in a more suitable place
- the new place should be at least 30 meters from the tree
TIP: If you regularly hose down your fruit trees with a strong jet of water, you can prevent ant and aphid infestations.