The fruits of the blackberries are special in that they usually only ripen on the blackberry vines with a delay from the end of July until autumn. However, it can sometimes happen that the existing blackberry fruits do not want to ripen at all.
Why aren't my blackberries ripening?
If blackberries do not ripen, this may be due to the blackberry gall mite, which attacks individual fruit bodies and prevents them from ripening. To combat it, we recommend cutting back infected plants in autumn and spraying them with rapeseed oil in spring.
Often only parts of the blackberries are not ripe
It may seem strange to you that only certain parts of the blackberries on your blackberry plants may not want to ripen. This can be explained by the fact that blackberries, like raspberries, belong to the so-called collective drupes, whose fruits are made up of many individual fruiting bodies and seeds. If the blackberry gall mite sucks on individual fruit bodies, only the affected parts no longer mature. However, the remaining part of a blackberry fruit is usually no longer attractive for picking.
Manual control measures
An important measure to combat the blackberry gall mite in its winter hiding place is to cut the infected blackberry plants. The tendrils should be cut back as far as possible in autumn and the dried cuttings should be burned in a controlled manner. This means that only significantly smaller numbers of the mite can overwinter near the blackberry plants.
Injecting with biological agents
Chemical agents to combat the blackberry gall mite are available from specialist retailers, but they sometimes put a strain on the fruits intended for collection in summer. But there is also a spray that allows the fruit to be consumed safely after washing. To do this you will need the following things:
- a bottle of ordinary rapeseed oil
- a spray bottle with a fine nozzle
- some water to dilute the oil
Add just enough water to the rapeseed oil in the spray bottle to give it a sprayable consistency. Ideally, spray the young shoot tips of the blackberry vines with this liquid in spring. Blackberry gall mites that are hit will die without the plant or its fruits being contaminated by the oil.
Tips & Tricks
Pests can sometimes only be controlled in your own garden for a short time if they permanently migrate back in from neighboring gardens. If there are neighbors' blackberry plants near your blackberries, simply point out the problem with blackberry gall mites to your neighbors. He will probably be grateful for this tip and the pests can be repelled more comprehensively.