Have you found fat white larvae in the potting soil? Then they are probably grubs. Not all species are harmful, but there are also root-eating larvae that should be combated. We explain how you can fight grubs in flower pots.
Are all grubs in flower pots harmful?
First of all: not all grubs are the same. The collective term refers to the larvae of four species of beetles, including both pests and beneficial insects. These are:
Rose beetles – grubs: They are useful in the garden, but harmful in the flower pot
Their larvae are considered beneficial insects in the garden because they actively participate in the formation of the hummus layer in the soil. They feed exclusively on rotting plants. These white larvae have no place in the flower pot, as they attack the roots of the plants due to the lack of a food source.
How to recognize rose beetle larvae:
If you place them on a smooth surface, they will turn on their backs and move forward.
Here's how you can get rid of rose beetle larvae:
You can move them to a flower bed or, even better, to the compost heap.
Rhinoceros beetles – grubs in a flower pot
The larvae of rhinoceros beetles are significantly larger than those of the other three species. They only eat rotten pieces of wood. In the garden they feed on dead wood, in the flower pot they stay in rotting wooden trellises or in the upper layer of cow mulch.
How to recognize rhinoceros beetle larvae:
At up to 10 cm long, the larvae of rhinoceros beetles are significantly larger than the other three species and have a cylindrical body.
How to get rid of rhinoceros beetle grubs:
Water the plants from above with the garden hose until the larvae emerge from the soil. Then pick it up and place it near a bush or tree. Alternatively, you can wait until it rains really heavily - the heavy rain will also bring the larvae to the surface.
It's better not to kill the beneficial insects in the garden, but simply to relocate them. If you have the bucket on the balcony, you can bury the beetles in the root area of a tree in the nearby park. This means the larvae have enough food and also do something good for the environment.
Harmful grubs in the flower pot: Fight the May and June beetles
Unlike beneficial insects in the garden, the next two types of beetles are pests. The May beetles and June beetles have larvae that look very similar. But some appear in May, others - in June and often in large numbers.
Not only the larvae, but also the beetles feed on healthy plant parts such as roots, shoots and leaves. In the event of an infestation, the entire plant is at risk. You should therefore definitely fight them - even in the flower pot. We list different variants on how you can do this.
Geraniums are poisonous to cockchafer grubs
1. Have it onceGrubs in a flower potHave you seen it and now want to replant the pot? Then clean thoroughly, dispose of soil and plant with geraniums first. They are inedible for the grubs and can drive them away from the flower pot.
2. If you plant young plants, you can cover the soil with garden fleece in April to prevent new eggs from being laid.
3. If large potted plants are already infested with pests, you can use nematodes to combat the larvae. They are tiny and feed on the pest's grubs.How to use nematodes against fungus gnatsfind out here.
4. If the flowers tolerate it, you can fertilize them with calcium cyanamide. The fertilizer is toxic to the grubs and acts like a mild herbicide.
5. Regularly collecting grubs after every heavy rain can also work wonders.
6. They can attract natural enemies of beetles such as birds and hedgehogs. Sometimes you don't need to do anything, the animals recognize the flower pot as a natural source of food.
7. To avoid an infestation, stop lighting the balcony and terrace in the evenings from April onwards. The light attracts larvae and beetles, which are active early in the morning and late in the evening.
8. As a preventive measure, you can also cover the soil in the bucket with river stones or coarse-grained gravel to prevent egg laying.
9. Plant the flower pot with ground cover plants. They will cover the soil and make cockchafer access difficult. This is how you turn the flower pot into an unpopular nesting place.
10. It doesn't help if you have only protected one pot from the pests and it is then placed in the middle of an easily accessible area or near accessible flower pots.
Sometimes caterpillars can also be found in the soil. What it is and what you can do about itfind out here.
