Here in the U.K autumn is rapidly giving way to winter and it’s now time to complete some very important work to ensure your bonsai have a good dormant season. Neglect this work at your peril.
When keeping bonsai it is important to follow good nursery practice. It’s good for your bonsai and it’s good discipline for you too. It’s important to have respect for our bonsai and a little winter care can make a BIG difference to how well our plants perform next spring and summer.
Now that leaves have fallen it’s time to have a good clean up. Keeping your bonsai garden clean is vital if you are to keep healthy trees. In general we do not recommend pruning at this time, pruning scruffy trees now can result in die back and some other problems. If your trees need a prune leave the work until next year just before you see signs of life.
Following these simple steps will make your bonsai look good and will improve your overwintering success.
1. Remove the remains of shed leaves of deciduous trees. Sweep the soil surface clean and remove coverings of moss, weeds and any liverwort. This improves air circulation through the soil and will help prevent root rot. Make sure drainage holes are clear and clean, slugs in particular love those little nooks and crannies. Also remove any fruit still remaining. This will prevent it rotting and harbouring pests. It will also stop pigeons breaking ramification from the upper part of trees as they perch on top and try to pull the fruit off.
2. Trees that have become green with algae should be sprayed with our Algae Cleaner. Remove sphagnum moss that may have formed around the base of the tree with a brass brush. Deadwood areas should be scrubbed clean inside and out and preserved with appropriate products – Bonsai Deadwood Preservers. For more information on preserving deadwood see our article Preserving Bonsai Deadwood. This work will prevent fungal infection and will rid the tree of many overwintering pests. It will also ensure craggy bark survives the winter.
3. Benches should be scrubbed or pressure washed and then disinfected with a product like Jeyes Fluid. Spray down the underside too. A lot of pests can spend winter hidden in your benches, particularly if they are wooden, just waiting to crawl all over your lovely bonsai in early spring.
4. Clean up and dispose of leaves and other detritus. This material is a MAJOR carrier of pests and fungal disease. If you have ground cover such as concrete, Mypex or even gravel give that a good soak with Jeyes Fluid too.
These few simple steps are just good nursery practice and if followed will prevent a whole host of summer problems that are common to all bonsai. A little work now will prevent a lot of problems next year and your bonsai will look a lot better too.
To read more about winter care of bonsai see our Guide to Overwintering Outdoor Bonsai