Winter protection of shohin-bonsai

Properly a problem that costs many worries for the lovers of the tiny trees around the world.

And the smallest of bonsais do need some extra attention trough their dormant period, with sometimes very cold winters in Europe.

You have to be aware of the very different climates we have around, and therefore use common sense when doing for instance a shelter for your Shohin-bonsai through the winter period.

There can be big differences in the climate locally in a little country like Denmark, and even more throughout Europe. And it will of course be even more drastic counting the rest of the world. This is just to tell you, that you have to be very careful to know which conditions your trees can adapt too.

Some guidelines for protection and daily care in the winter

If living in a place where the winter brings frost or even snow (like my place), one has to take some precautions to bring the trees safe through the winters.

Species

Be well aware of the species you have as Shohin-bonsai. Are they in general able to live in the climate you are living in? And, most important, do you know if they tolerate heavy frosts?

Storage room

I always place my bigger bonsais in a cold frame, or in a cold (not headed) greenhouse, from the start of November or when frosts starts to be steady (sometimes in December).

A greenhouse is in danger of getting to hot on a sunny day even when it is freezing. So either have it shaded or use a room that will not get headed by the sun. It does not need to be a very bright room, because many trees, even conifers needs only little light during the cold season in Northern Europe.

When spring arrives I take them out again. That’s around March to April. It all depends of the weather, and you will find me bringing some of my bonsais in and out a few times, because of shifting weathers. But only in the start and ending of the sheltering period. It can be necessary to protect from heavy steady raining periods in late autumn as well.

If temperatures should drop heavily, down to around – 15 Celsius/ 5 Fahrenheit, and rarely lover, I will take my bonsais to my cold basement where the temperatures are around 8 Celsius/ 45 Fahrenheit. But only until the temperature rises again outside. The trees needs the touch of frosts to kill over wintering insects and eggs in the bark, and to rest properly.

Protection from cold winds and sun

Shohin-bonsais needs protection for the cold winds, exactly as their bigger mates. It is very important to keep any bonsai from winds when their pots and soil are frozen, because the roots will not be apple to take up frozen water. And both wind and sun will dry out the leaves of especially evergreen species. But also when a tree has dropped every leave, it will still be transpiring through the bark and their buds. It may be slowed down very much, but the tree is still active through the whole winter period.

When a tree stands in a greenhouse the sun will still be able to heat up the leaves on a conifer to quite warm degrees, even when it is very cold. Therefore it is of big importance to shade a little when the pots and soil are frozen. Ells the tree will die from dehydration, when the leaves transpires damp in order to cool down the leaves.

A Shohin-bonsai is of course very sudden dehydrated, because of the very limited amount of soil and spare roots compared to the amount of leaves.

Winter exhibition

It is very satisfying to bring in a Shohin on a winter day. Just to observe the details of the naked branches and new buds.

Or even to bring them to a winter exhibition where the winter silhouettes of a leafless tree is very pleasing.

Just remember to bring them back after a day in the heat, so you don’t disturb the trees more than necessary.

Potentilla fruticosa