How to survive frost raspberries in the garden and pot
In order for raspberry plants to survive the icy temperatures in winter well, they need warming protection, especially in tubs. Outdoor raspberries are tougher, but they also appreciate a little attention during the cold season. Wintering raspberries is guaranteed with a few tips.
Berry bushes are hardy and can all overwinter outside just like raspberries. Strawberries, red currants, goji and blackberries usually tolerate about -20 degrees. Raspberries and gooseberries can withstand almost -30 degrees. Blueberries and black currants can even easily withstand temperatures beyond -30 degrees.
However, even if a plant is hardy and frost does not affect it much, it still has one weak point: its roots. These are more sensitive than the above-ground part of the plant, but are crucial for its survival. Some plants can freeze completely above ground and still resprout in the spring if their roots have survived the winter well. Therefore, we should pay special attention to the roots running shallowly below the soil surface when overwintering raspberries.
Is it possible to overwinter raspberries indoors?
Overwintering raspberries indoors is not a good idea. The plants need the cold temperatures to go into hibernation. Indoors it is much too warm and the air is too dry. Light is already scarce in winter anyway – indoors the plants then reach even less sunlight. Under these circumstances, the plants become stressed and more susceptible to pests.
Can raspberries be overwintered in the cellar?
The cellar is usually colder than indoors, but it is also darker. Conditions are not ideal and a raspberry is much better off outside in the winter – even if it is freezing. With adequate protection, your raspberry will much prefer to overwinter outside.
Winterizing raspberries: In a pot, they need frost protection
In the pot, the roots are defenseless against the cold temperatures if no measures are taken. Frost reaches them effortlessly through the pot and soil. It is therefore essential to insulate the planters sufficiently to protect the roots.
This depends on the exact location of your raspberry. On terraces at ground level there is a risk of ground frost, while on higher balconies icy winds may be more of a problem. It also makes a difference whether mild or very cold winters are the norm in your region. The more sheltered your raspberry plant is, the less lush your frost protection will need to be.
- Styrofoam or wooden board as a base.
- Insulating protective fleece (garden fleece, jute, bubble wrap, or similar)
- Robust cord for fastening
- Leaves, straw or fir branches for mulching
Before you get started with your insulation, it’s a good time to check for pests and diseases. Even though most pests can’t survive the frost, this makes sense. After all, every now and then there are very mild winters and surprisingly cold-resistant crooks. Once the coast is clear, you’re good to go!
- Start by covering the soil, for example with a layer of leaves. This will provide good moisture balance and keep you warm.
- Then wrap the planter generously with a fleece or other fabric. There are, for example, jute bags especially for planters, but also an old blanket is suitable. Make sure that you will still be able to water the raspberry later. You can then secure the whole thing with a sturdy cord in case the protection doesn’t hold on its own.
- For extra security, you can fill the spaces between the fleece and the pot with leaves or straw, which will provide additional insulation.
- Once everything is well wrapped, you can move your raspberry to a protected spot.
- Once you have found the perfect spot, you can grab your wooden or styrofoam board and place it under the pot – this is important in case of ground frost.
- If you have more plants on the terrace, you can also place them in groups. This way they can support each other and intercept wind and rain.
If you don’t want to go to so much trouble to protect the containers and you have a greenhouse at your disposal, this is also a good place for overwintering. Here it is especially important to water regularly!
Raspberries in the garden: frost protection as needed.
Outdoors, your raspberry usually doesn’t need extra frost protection. But again, it depends on where exactly you live. In regions with very cold winters, it is advisable to cover the soil around the plant with leaves, for example, and additionally with fir branches. Such a mulch layer protects the roots from the cold.
Freshly planted and still young raspberry bushes should also be somewhat protected in their first winter. However, you only need to protect the root area.
Wintering raspberries: don’t forget to water them
Note that your plants must be supplied with sufficient moisture even in winter, otherwise they can dry out. If it hardly rains or the tubs are protected against a house wall so that rainwater cannot reach them, you must water regularly, especially if the air is very dry. It is best to choose frost-free days and water in the morning or at noon, as it usually gets colder at night and there is a greater risk of frozen soil. However, if you have the tubs sufficiently well protected, this danger should be rather small.
Beware of too much winter sun
While light is important for raspberries, you should be careful not to expose them to too much sunlight, especially in late winter. Some winter days are still cold, but the sun can warm up some areas quite a bit on patios or balconies. Potted plants sense this warmth and, at worst, think that spring is just around the corner and it’s time to resprout. Of course, that’s not a good idea when it gets frosty-cold again at night or when it’s cloudy. You should then put the plants in a shadier place or cover them with a light fleece or similar.
Wintering raspberries: Cut back or wait until spring?
Whether to cut back plants in the fall or wait until spring is often a matter of controversy. There are the “tidy up” types who like to sweep the garden clean in the fall and make a neat start to the winter. Another approach is to just leave everything alone. Depending on the plant, there are good arguments for both sides.
With raspberries, it depends mostly on what variety it is: Summer or fall raspberry or a twice-bearing raspberry? The easiest way is to cut off the older shoots of summer raspberries and twice-bearing raspberries right in the summer after harvest. You can also wait until spring, but then it’s a little harder to tell older and younger shoots apart.
Fall raspberries should be cut back completely in the fall after harvest. A second deadline is February or March, before the new shoots sprout.
I have 30 years of experience and i started this website to see if i could try and share my knowledge to help you.
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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.
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