|Why don't you give bonsai a present this year. The Texas State Bonsai Exhibit is finally progressing but could use more donations. Find full details about the new area in Zilker Park, Austin and you can also donate on the web at:|
Make checks payable to and or send donation to:
25515 Stormy Rock
San Antonio, TX 78255
Try to find some good material for enhancing your collection. It is hard to find decent material in a landscape nursery. If the club has a dig scheduled, be a part of it. There are many places where you can find one or two specimens to dig, in town as well as in the country. The problem is in finding a place with enough material to warrant taking the whole club. If you know of a possible location or have a friend with some land (it doesn't have to be very close) tell one of the officers about it. This comes under the heading of 'be an active member'. The rest of the group especially your program chairman will appreciate it.
The big thing this month is to make sure that the bonsai do not dry out and to protect the roots from freezing. Do not leave them up on their benches. Know which species should be left outdoors. They may be set on the ground. Add a dense mulch to the pot rim and then add a looser mulch on top.
Evergreen types especially and deciduous to a lesser extent should not have the root ball subjected to alternate freezing and thawing. That process tends to tear and damage the roots. Placing the trees on the ground and using a mulch will minimize this problem.
Deciduous trees should not be placed where they receive winter sun. After a period of dormancy, the heating of the tree could possibly cause it to break dormancy prematurely. If that happened you would need to keep it above freezing the rest of the winter. After they go dormant they have no need for any sunshine.
While they are dormant examine the twigs, branches and trunks carefully for scale insects, scale are sucking insects that usually cover themselves with a hard impervious shell that is very resistant to insecticides. Some are pretty small and look like specks. You might want to search online for something like 'scale insect bonsai' and get some pictures. Horticultural oils (available at garden stores) work good by filling their pores and smothering them. Oils can be applied now and you get a more thorough coverage while the trees are dormant. The only other way is to use a systemic insecticide (make sure it is labeled for scale) during the growing season.
Since the trees are not using as much water during dormancy it is easy to overlook checking on them. The low humidity usually found during winter helps dry the soil. Winter sun can be pretty hot and if it shines directly on the pot it will hasten the drying process. Winter will usually also be more windy. Therefore, however you bed down the trees, you need to check the dryness often. The same trees that needed more water last summer will also need to be checked more often during the winter. I think that more trees are lost during the winter to having the soil dry out than from the actual cold.
Especially watch the plants that will need repotting next spring. Pots full of circling roots do not have much soil to hold water but those that had a lot of organic matter in the soil mix may be soggy. Organic matter that has composted during the summer will be very fine textured and hold on to the water a long time and may also interfere with drainage.
Plants have different degrees of hardiness for their top growth and their roots. The reason being that the ground acts as a large reservoir of heat and here in Texas seldom freezes more than an inch or two down. Therefore, plants like the pomegranate and crepe myrtle which are at the northern extent of their range outside will only be hardy to 32 degrees in pots.
Any plant that you are unsure of should be protected from freezing. This can be a problem because if they are not kept cool after they go dormant they will break dormancy and start to grow too soon. Growing without sufficient light causes long spindly growth which you cannot control. My best solution for this when I lived in town was to have a long platform with two wheels that I pulled into the garage on nights where freezing was forecast and kept outside at all other times.
The cold weather will keep any insect problems under control outside. You should use a dormant oil spray to kill over-wintering insets and eggs. A dilute spray of lime-sulfur can be used on deciduous trees if they have no green at all which will also control fungal spores but be sure to follow label directions carefully. You should watch for damage from rodent types, rabbits, squirrels and rats. They will seriously prune branches and strip bark in short order.
A caution on lime sulfur --the same stuff we use on jin and shari. The liquid lime sulfur is pretty caustic so should be used with caution. If used as a dormant spray application should only be made to fully dormant plants, deciduous trees with tight winter buds, not on very warm days, and only when diluted as directed on the bottle.
Bonsai in greenhouses or indoor bonsai will need to be watched for the normal indoor problems. Low humidity, spidermites and scale are the biggest problems here. Trying to keep the humidity up by placing your trees on a humidity tray can possibly give you some soil problems, root rot or some other fungal disease. I basically use the same controls in the greenhouse that I use outside all year.
You can take advantage of the winter slowdown by getting pots ready for spring, clean and sharpen your tools, study what changes you would like to make on your trees and so forth. Making notes about what needs to be done on an individual tree is great but if you are like me the notes and trees are usually a long way apart. If you place a colored stake or ribbon on the tree you will see instantly which one needs what done. For example, I am using red for needs repotting, purple - needs a new pot, yellow - serious pruning, orange - should be restyled etc. These can be put on during the year if you make that kind of decision as you are doing general routine work.
By John Miller - Reprinted From 2015