Not all planters are winterproof. Frost is particularly bad for buckets made of wood and ceramics. It is important to protect them as best as possible.
In spring and especially in summer, lush flowering and green plants in tubs are a source of joy and beautify gardens, terraces and balconies.
As soon as the temperatures drop towards zero at night, you should think about how to protect not only your plants from the first frost (see tips at winterschutz.de), but also the planters. After all, you'll want to stock the boxes with flowering plants again in early spring.
Different materials tolerate frost differently
When moisture in the ground freezes, it expands. With some materials, this can cause the bucket to burst. This is particularly the case with ceramic pots, for example.
Even wood will not survive the winter without damage if it is not cared for and prepared. Wood is a natural material and must be regularly treated with a protective varnish.
Plant pots made of fiberglass (a mixture of fiberglass mats and plastic) are best suited. These are particularly stable, weatherproof and UV-resistant (Source: pflanzkuebel-direkt.de)
But probably the biggest advantage compared to buckets made of stainless steel, terracotta and concrete is the relatively low weight. So you can also easily transport the large plants.
Basic rules for wintering
In principle, of course, only plants that are declared as hardy may remain outside. The following rules apply to these plants:
❶ Create a drain for the irrigation water
Ensure that irrigation water always has the opportunity to drain downwards. To do this, however, you must drill holes in the bottom of the container before planting, if they are not already there.
Note: If the irrigation water cannot run off, the flower pots will freeze to pieces.
❷ Check drainage
Check that the drainage in the flower pot is working properly. It is best to put a layer of stones on the ground for this. The plant pot should be at least onetenth of its height must be filled with the drainage.
A potsherd in front of the drain hole can also be very helpful here. In the video from helpter.de you will find more detailed information on the subject of "drainage in flower tubs".
❸ raise bucket
In general, your plants should not stand directly on the ground in winter, as this would prevent the water from draining properly. Even the otherwise so typical coasters are not a better solution in winter. Too much water can collect here during rain or melted snow, which quickly freezes overnight.
So it's best to put the buckets up. Chairs, stools or other winter-proof frames are suitable for this.
❹ Protect tubs in very severe frost
At extremely low temperatures, it is advisable to wrap the planters themselves with bubble wrap or another insulating material such as fleece. If you want to keep the natural charm of your garden, you can use coconut mats in addition to straw mats or jute felt:
❺ cover potting soil
Cover the soil with straw, leaves or special mats to protect the plants from severe frost.
Tips for overwintering non-hardy plants
For plants that are not hardy, other preparations must be made. A frost-free place with enough windows, for example a conservatory or a bright garage is ideal for this.
Non-hardy plants should not be left outside and should not be exposed to freezing temperatures. A basement room with neon lights or similar will not work as the plants need real daylight. In addition, there must be enough space between the planters so that they can still be easily supplied with water. It is usually sufficient to water the plants once a week.