Astilba will overwinter well and will bloom Lush if you don't make these Mistakes. Talking about my experience
The beauty of Astilba is increasingly "settling" in gardens - there is something charmingly extraterrestrial in her seemingly fluffy appearance, she is elegantly combined with any other plants and is unpretentious.
However, on the eve of winter it needs special care. And guided by my personal experience, I want to warn you against mistakes that can destroy her!
Fertilizers
There are two mistakes that can be made in this area. The first is to decide that faded plants go into hibernation and do not need nutrients, which means that feeding can be postponed until spring, when they need strength for colorful flowering.
Personally, I was not so wrong, but I know for sure - then in the spring I will have to uproot what is left of the Astilba, who could not survive the winter due to exhaustion. The second is the opposite. This is when the gardener generously brings in all the minerals and more!
Personally, I managed to feed the astilba with nitrogen in late autumn, because of which the bushes began to grow young shoots, which, of course, froze out with the onset of cold weather, which weakened the astilba. In fact, on the eve of wintering, astilbe only needs potassium and phosphorus.
You can take superphosphate and potassium magnesium in equal proportions. For one bush, about 20 g of fertilizer in granules, just scattered around it, is enough.
Pruning
Many plants overwinter well just after sanitary pruning, and even a slight shortening. For several years I was afraid to shorten the astilbe too much, as a result of which some of the plants died by the spring, and the rest bloomed belatedly and sluggishly.
In fact, it turns out that astilba should be cut almost at the root, but so as not to affect the buds that form slightly above the soil level in the root part of the bush.
Shelter
It is believed that astilba can tolerate temperatures as low as -25 ° C. After one severe winter, a part of the aboveground part really survived on my bushes, but the root system is frozen!
I am sure that the situation was aggravated by the fact that these were plants over 5 years old - the underground part of which grows rapidly close to the surface.
To thoroughly insulate the astilba, little is needed - a fence is built around it of stones or sticks, boards, then they throw in textile material and fix it so that it does not blow away with the wind.
In a snowy winter, nature will take care of the rest - "covering" the astilba with a "blanket" of a thick layer of snow. If winter is expected to be snowless, you can additionally cover it with coniferous "paws" under the textile material.