|Maybe it's time for a reminder that articles like this are always just guidelines. Each tree in your backyard is a special case and you should look at it individually each time you water. Be sure it is not getting stressed. Is it really healthy? Any signs of problems --wilting, color ok, leaves good? Does it need attention immediately? If so place it aside and come back to examine it and take appropriate action. I have repotted deciduous trees in July but not in the normal manner. At an abnormal repotting special attention is needed during the repotting and for the after-care.
Learn to think in terms related to plant characteristics instead of calendar periods (i.e. use 'when dormant' instead of October, 'candle growth' instead of April, etc). That will enable you to read bonsai articles correctly whether written in Japan, Florida or wherever. Note that some tree cultivars (like the cork bark black pine) are notably weaker than the standards of the species and require different pruning and care.
You should have your winter quarters ready. Select one for deciduous trees that will be out of the sun. Air circulation is good but too much wind will desiccate them especially in freezing temps. Be sure you will be able to check their watering. Clean up all debris.
Most important in winter is to keep the soil moisture at a proper level. This sometimes is hard to do because the trees do not use as much water as when they are growing. However the cold winds will dry out the tops quickly. I believe that most winter damage in Texas is due to lack of water rather than to low temperatures. Mulch helps keep the roots warm and retards evaporation but it makes for difficulty in seeing if the soil is damp enough. Most soils with enough organic material to keep the tree happy in the summer will be too wet if watered daily in the winter and wet cold means root rot.
Before putting the trees into winter storage treat them for over-wintering insects and eggs. Dormant oil spray is good on trees with no green, foliage or buds. A dilute solution of lime sulfur is an old gardener's dormant spray for insect and fungus control. Use it on very cool days and dilute it 1 part lime sulfur to 20 parts water. Be sure to read the label on your bottle in case there are different strengths available. This solution should also be applied to bench tops, posts and the soil surrounding them (if you have gravel instead of grass) to eliminate hiding eggs and spores. If you have a greenhouse treat it also before the weather gets too cold to put your plants outside or move them to one end while you treat the other end.
At this time of the year deciduous plants do not need fertilizer. Evergreens will continue a slow growth and will benefit for a light fertilizer feeding. Use one with a lower nitrogen (first number) like 0-10-10 or 8-8-8 at no more than 1/3 the recommended feeding rate.
Watering should be done with care during the cool and/or cold weather. Deciduous trees will use some water to replace what is lost to winds and evaporation. Evergreen trees will need a little more but not as much as in summer. The easiest way is to sort your pots into groups, those that dry quickly, those that are slower to dry, and those that seem to stay damp. This will let you water faster and yet not over-water the ones staying damp. Make a note to repot the ones staying too damp.
Repotting of hardy trees can be done anytime the trees are dormant. However it is safer to do that chore in the spring as the buds are swelling. New roots will start forming immediately upon repotting in order for the tree to absorb water. If you do repot in the fall you should protect the new roots from freezing during the winter. Do you need to change the pot? Making notes at this time while getting the trees ready for winter will give you 3-4 months to find the proper pot.
When trees go dormant which indicates a reduced sap flow they may be pruned, that is have major limbs removed. Trimming may also be done while the leaves are off the trees and you can see what you are doing. Evergreen types will probably still be active. Pruning them should be held until later. Foliage can be removed when half has turned color to remove some pathogens and to enjoy their winter silhouette.
BIG NOTE: If you have a tree that is weak and unhealthy you should not attempt to style it in any way, just get it happy by adjusting its soil, feeding and getting rid of any parasites. Styling just adds to its stress and problems.
By this time any tropical you have should be under cover. Most do not like the temp below 50 degrees. All tropicals should be checked and treated for any insect problems since any insects will multiply fast when they get into warmer quarters. Spider mites and scale can be especially damaging if the plant is moved in the house where the humidity is low.
The semi-tropical plants like crape myrtle, pomegranate, pyracantha and some south Texas natives need to go dormant to stay healthy over a long time but they cannot take much cold on the roots. They will be killed by temps somewhere between 25 and 30 degrees. These I set down on the ground and mulch for light freezes and then bring into a protected area for the colder winter. Sometimes I will let them go dormant for a month and then take into the greenhouse to start early and I can enjoy their new foliage in January.
By John Miller - Reprinted From 2015|