Of course, grubs in flower pots are annoying, but not a disaster. Because in contrast to an infestation in open garden soil, the infestation radius is clearly limited here. In order to get rid of the pests, simple, mechanical and biologically gentle measures are recommended.
Engraved grubs can be driven to the surface by wetness
countermeasures
If a container plant takes care of itself, this can be an indication of a grub infestation. This is because grubs eat roots of living plants, and not just outdoors. If you discover an infestation, the following countermeasures are advisable:
- Manual picking
- flushing out
- Drift upwards through wetness
- nematodes
Manual picking
The most obvious and direct method is manual collection. To do this, loosen the root ball from the bucket, shake off the soil carefully and pick out the larvae as thoroughly as possible. Because of their yellowish-cream-white color and their size of about 5-7 centimeters, they are also easy to recognize in the dark soil.
The problem with the method is that it is somewhat tedious. On the other hand, you will hardly discover any grubs. It is also not good for plants with a dense root system that cannot be penetrated with the fingers.
flushing out
Especially with densely rooted plants, you can try to flush out the pests with a strong jet of water. Of course, the root system must be sufficiently robust to avoid damage. But even with this method, some grubs can slip through the net or get out of sight with the flow of water, causing them to wreak havoc again a few meters away.
Drift upwards through wetness
Like earthworms, grubs are driven to the surface of the earth when it rains. You can use this habit. Put the root ball of your container plant in a soaking bath and wait for the animals to show up on the surface. You can then collect them from there. But even this method does not claim to be a complete removal.
nematodes
A fairly effective and biological variant is control by predatory nematodes. Certain nematodes of the predatory genus Heterorhabditis use larvae of pests such as May beetles, June beetles and garden beetles or vine weevils as hosts and kill them in the process. You can buy suitable nematodes in garden shops or on the Internet. The animals enclosed in clay granules can simply be removed with the irrigation water.
preventive measures
Repot regularly
Engraved grubs like firm ground. Therefore, as in the open garden soil, it is also important to keep the soil loose and weed-free with potted plants. Never leave plants in the pot so long that the root ball becomes completely solid and compacted. It's not good for the plant anyway.
Insect net for beetle flight
In order to deter May, June and garden chafers from laying their eggs in your flower pots, it is advisable to stretch insect nets over the tubs during their respective flight times. This is not particularly complex and only necessary when the adult beetles fly - and this only happens every few years, especially with May and June beetles and lasts only a few weeks in May and June.