When replanting or repotting flower boxes, an unpleasant surprise sometimes awaits: grubs comfortably basking in the ground! It doesn't help here - the root-eating pests have to be taken care of. We'll show you how.
How do you remove grubs in the flower box?
Grubs in flower boxes can be removed by mechanical collection or rinsing, a dipping bath that drives the larvae to the surface of the soil, or the use of predatory nematodes. Insect protection nets and garlic plants help prevent beetles from laying eggs.
How do grubs get into flower boxes?
Every 2-4 years, May and June beetles enter an imago phase in the cycle of May and June beetles, which is quite long for insects. In zoological terms, imagos are the adult beetles that only live for a few weeks to prepare the next generation. During these weeks they have the following tasks:
- Eating
- Mating
- laying eggs
The fulfillment of the first task is still all too painfully familiar to earlier generations of people: up until the 1950s there were real plagues of May beetles that stripped entire forests of leaves. After mating, the males die again and the females lay their eggs before they die. And to do this, they select places that provide a good source of food for the hatching larvae - i.e. wherever plants with tender, nutritious roots grow. Flower boxes planted with flowers, herbs or vegetable plants can also be chosen.
How to remove the grubs?
Mechanical: collecting or rinsing
The grubs should first be removed purely mechanically - preferably manually. If possible, remove the entire planting from the box by tilting it on its side and carefully loosening the contents. If the plants are already established and have a developed root system, you can search for the pests relatively quickly. Rinsing out the roots with a jet of water can also help with sorting.
Strategic: Dip or nematodes
Things are a little more difficult with young plants that are still tender. Because they can't really be removed from the box without damage and examined for grubs on the still young roots. A dipping bath can help here, completely soaking the earth and thereby driving the grubs to the surface. They can be collected there. The use of predatory nematodes (€7.00 on Amazon) is also recommended here, preferably in addition.
Note
If you have other planters on the balcony, be sure to check them for grub infestation.
Prevention
It is also advisable to put insect protection nets over the flower boxes or to plant garlic as a deterrent during the flight times of May and June beetles. This prevents the beetles from laying eggs.
