Wintering in the garden and on the balcony
Although blueberries are hardy and usually survive freezing winter temperatures well, blueberries in pots especially need winter protection. Let’s take a look at how to get our “fat blues” through the cold season well. What all do you need to consider when hibernating blueberries?
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Blueberries or blueberries? And what about raspberries?
Strictly speaking, most of the blue berries in our gardens are cultivated blueberries. This term is used to distinguish them from wild forest blueberries. These are much smaller, both the plant itself and the berries. But we also like to call our Bodo blueberry, because its berries are so wonderfully thick and blue – and after all, in English we also say blueberry.
Just like blueberries, many other berry bushes are very robust and hardy. Most blueberry varieties can easily cope with temperatures as low as -16 degrees. Raspberries and blackberries are also hardy. Currants and gooseberries are also hardy and do not necessarily need winter protection outdoors.
While blueberries are intended to be the main focus of this article, all of the tips related to overwintering apply to the other berry bushes as well.
Robust berries – How to overwinter blueberries
Blueberries are hardy perennial shrubs. They lose their leaves in the fall and then overwinter “naked” to grow new leaves in the spring. Fresh, new shoots also grow from the ground each year.
But even if a plant is hardy and frost does not affect it much, it has one weak point: its roots. These are more vulnerable than the above-ground part of the plant, but are crucial to its survival. Some plants can even freeze off completely above ground and still sprout new shoots in the spring if their roots have survived the winter well. Rhubarb, for example, has mastered this trick. Fortunately, this does not happen with blueberries.
In some years, however, it can be that it is already quite mild in late winter and the blueberries sprout anew. If there are night frosts in March or April, these young shoots are particularly at risk of frost damage. You can protect the plant in such a case with a fleece to warm its “cold ears” a bit. However, this is only necessary for the rest of the winter if temperatures fall below -20 degrees.
With blueberries, you should be more concerned about keeping their feet as warm as possible. This is especially important for tub plants, but even in the open ground root damage in winter is not excluded.
Overwintering blueberries: This is how it works outdoors
Blueberries and other berry bushes do not normally need to be protected from frost outdoors. However, berries are shallow rooted, which means that their roots tend to run shallowly under the soil. Therefore, if low temperatures or permafrost are announced, the plants will be happy to have a protective layer of mulch. Since this is useful all year round anyway, you may have already laid it around the plant anyway. Now in winter you can renew it again and spread the material thicker. Lawn cuttings or leaves are suitable. If the material is too light and in danger of being blown away during autumn and winter storms, you can additionally cover it with branches of coniferous trees or heavy bark mulch.
Your blueberries do not need more protection to survive the winter.
Wintering blueberries in a pot
In the pot, the roots are defenceless against freezing temperatures if no measures are taken. Frost reaches them effortlessly through the pot and soil. It is therefore essential to pack the planters sufficiently thick to protect the roots.
Of course, there are always exceptions. Perhaps you have a corner of your balcony or terrace that is so well protected that it doesn’t freeze or hardly freezes at all. Perhaps the winter will be particularly mild. In such cases, it is sometimes not necessary to pack the pot of blueberries extra. However, we think: better a little too much winter protection than frozen plants.
It is very effective if you place the pot on a wooden or polystyrene plate. So the blueberry is already protected from ground frost. In addition, you can protect the entire pot with materials such as jute or special garden fleece. Such a fleece is available in different thicknesses. Note that thin fleece is not as tear-resistant and may not be reused as often. You can also leave some space between the pot and its packaging and fill the space with leaves or straw, which will provide additional insulation.
From above, you can protect the soil with a layer of mulch, just as you would do outdoors.
Also in winter: Do not forget to water
Note that your blueberries must be provided with sufficient moisture even in winter, otherwise they can dry out. This is especially true for potted plants. If your blueberries are protected by a house wall, so that rainwater cannot reach them, you must water them regularly.
But even outdoor blueberries may be thirsty if there is little rain and rather dry winter weather.
It is best to choose frost-free days. Water in the morning or at noon, as it usually gets colder at night and the risk of freezing soil is greater.
As I said, you can apply all the info from this text to raspberries & co as well. If you know how blueberries overwinter, you can also bring your other berry bushes well through the cold season.
I have 30 years of experience and i started this website to see if i could try and share my knowledge to help you.
With a degree a Horticulture BSc (Hons)
I have worked as a horticulture specialist lead gardener, garden landscaper, and of course i am a hobby gardener at home in my own garden.
Please if you have any questions leave them on the article and i will get back to you personally.