|There is no way you can rely on the calendar to plan what you need to do for your bonsai. In April, May & June this year I probably had three days total that all my trees needed watering. And only a few more that they really needed to be checked. Then from July 5 to August 24 (7+weeks) there was not a drop of rain and a lot of temps above 100. You just have to know what needs to be done and then do it.
When it rains days on end, tilt the pots to aid drainage and to make sure they are not clogged up. When it is hot and dry, maybe water 2 to 3 times a day and protect plants and especially the pot from direct sun.
It is probably not late enough for the bonsai to go into their pre-dormancy slow down period. If they are still growing, continue twig pruning and other summer care. If air layers have developed roots they may be separated and potted.
In Sept and Oct there will still be some days with pretty hot temps. So as the sun changes its angle make sure that the pots do not get too hot in the late afternoon sun. Also watering now becomes harder. As trees slow their growth they do not take as much water. Neither will they transpire as much on the cooler days. So check each one separately and water as often and as much as the individual tree requires.
Check the trees you still have wire on. When the cooler days get here some trees will expand their branches and get wire cuts rather quickly. You need to check them periodically over the winter also. Cut the wire off. You can easily break the branches trying to unwrap the wire and it's just not worth trying to save the wire. Work from the outside end of the wire back so that you do not overlook a small piece of wire. If you have trouble seeing each twist of the wire don't cut, just unwrap the wire (with care). If you miss a turn of the wire you will make an unsightly bulge and the limb will probably have to be cut off. If you need to reapply some wire take care to not follow the same path.
Help your trees go into dormancy. The general rule of thumb on fertilizers is to stop giving nitrogen early in September and fertilize with one that has a formulation like 0-10-10 or 0-0-10. They will need less water as they quit active growth but on warm days trees with green foliage will still transpire and will have need of that water. Most tropicals have a dormant season also but it is usually caused by dry conditions rather than cold. These types need to be hardened also by cutting the fertilizer to halt active growth and give them lighter watering. This will enable them to withstand the transfer to the greenhouse better.
Fruiting bonsai spend a lot of energy growing fruit. They should not be allowed to fruit heavily each year. They benefit from a light fertilization at this time. Flowering bonsai especially need to receive the minor elements. Get a good fertilizer, such as the Espomaplant-tone fertilizers, that include them in their mix for good color development. They should be listed on the label.
There is not too much to be done on deciduous trees at this time. Bugs and other problems are usually not a matter of concern since the foliage will be dropping soon. Evergreens and tropicals will still need to be watched for their insect problems, especially the spider mite which will be active into fall. Use the organic spray formula to control them. If we should have a stretch of damp weather you should be watching for fungal problems, leaf spot, mildew, etc. Treat fungal with potassium bicarbonate, (baking soda-sodium bicarbonate-will work about as well). I would be okay with using a 1% hydrogen peroxide solution at this time of the year for fungal control.
The organic spray formula is one tablespoon each of liquid seaweed, fish emulsion, 5% apple cider vinegar, and molasses in one gallon of water. Spray top and bottom of leaves and trunk thoroughly on a regular basis (7-10 days). If you miss getting scale in their vulnerable crawler stage, you may have to go to a systemic.
Pruning and trimming "can" be done any time that there is not a lot of sap flowing but is usually advisable to do it during dormancy. Sap flow is indicated by the foliar activity of the plant like in the spring. If your tree went into summer dormancy which sometimes occurs during hot weather then the cooler weather might result in a larger sap flow in late summer or early fall. If your plant gets a flush of new growth it would be advisable to postpone large pruning cuts for a while. Basically let your tree tell you when it is ok to operate.
Two other things you can do now. You should prepare your winter quarters and you should study your evergreen trees to determine if you need to do any restyling later on this fall. Bonsai in Texas should be a year round sport, you don't need to cover them completely like up north. Try to put them where you can see some of them. Just remember that they will still need to be watered and evergreens will need some sun. A mulch cover over the pots on the ground will minimize temperature extremes.
Don't wait for the freezing weather to be forecast to check on the place you expect to winter your bonsai. Make sure that it is clean and that you will be able to check the water needs of the trees. It should be somewhat protected from winds but should have some air movement to help prevent molds from developing. Being in a location where you can see the trees would allow you to enjoy the winter silhouette, i.e. the branch structure and twiginess, that is a great part of deciduous bonsai.
Do not be in a great hurry to put your trees in winter quarters. Keep them where you can enjoy them as long as possible. That way you experience the color change and all that occurs in the fall. Know when the freeze can be expected and then listen to the weather forecasts and put them down in the place prepared before hand.
By John Miller - Reprinted From 2015|