Monthly Tasks - October
Based on San Francisco Bay Area Climate by Mitsuo Umehara
Early and Mid-October
Continuation of Needle Pine Work from September
Black pine, red pine - Remove old needles and cut back new branches. Wiring and transplanting trees can be done now, but be careful to notice new buds and avoid wiring were buds preparation has or will begin.
Five-needle pines - Allow 10 days rest in between the shaping and transplanting for better results.
Spruce - Eliminate excess branches and shape; hold transplanting for the spring. Spruce and cedar can now be wired.
Shimpaku, yew - Best season to do the shaping, wiring and transplanting. Don't forget the maintenance of shari as well.
Early bloomers -Don't wait till the foliage drops; it will be too late by then. Transplant now; the foliage will drop later and will form buds in the spring. Fruit tree work can begin now in earnest as leaves begin to display fall color.
Japanese maples - Some varieties, such as chishio and shindeshojo and the katsura (cercidiphyllum japonicum) tree will open much sooner than most other maples. They should be cut back and transplanted now. Remove leaves to limit mold, especially leaves that burn and begin to dry out. This is a perfect time to consider reworking tree apex and refining tops of the tree.
Quince, cherry variety - Change the apex if necessary and redirect branch tips if needed. Watch for the Crown Gall disease. Remove (prune) area. All the tools used and your hands should be disinfected with rubbing alcohol. (Some people prefer Hexol for tools because it doesn't remove lubricating oils.) Another disease similar to Crown Gall, but won't kill the tree is root-nuts. Root-nut will develop on the finer roots; looks like tiny pearls. It will not kill the tree, but will slow down the growth considerably so remove by pruning. It's a good idea to disinfect pots with infected trees. Scrub with dish washing liquid and then rinse with alcohol. Alternatively, many horticultural references suggest soaking the pots in a solution of one tablespoon bleach per gallon water for 10 minutes before rinsing.
All Trees Must Be Ready for Winter
Improve air and sun penetration.
Reduce the amount of water gradually.
Watch the sunlight and move the trees accordingly.
Fertilizer - Autumn feeding should be applied generously. (For more information see Fertilizer Basics
For flowering, fruit, and berry producing trees: Use low nitrogen fertilizer (look for bulb and bloom fertilizer) or Seaweed extract when you water.
For deciduous trees: Apply 0-10-10, such as E.B. Stone Ultrabloom
For Conifers: Continue to give them a generous amount of regular fertilizer
Trees with nice fall color - Maples, trident maple, Stewartia, elm, etc.
Mist-spraying the foliage before sundown will prolong the beautiful fall color. This should be done in areas with good water. South Bay areas will still have to watch for molds and fungus.
A small amount of liquid fertilizer will strengthen the tree, but a large amount will delay the fall colo
Late-October
Spray - Trees should be sprayed after all work is done - and on a dry day when no rain is expected for a day or two. Insecticidal Soap or Ultra-Fine oil, sometimes labeled Volck oil spray is safe for most plants. You may also use Neem oil which will treat fungus and bacterial infections as well as kill insects, but will damage / kill some varieties of trees. Read directions carefully before applying anything to your tree. Do not use oil that is old / oxidized / discolored as it may damage your tree.
Digging - After the ground is soaked from an autumn rain, you can dig low-land trees out of the ground. Roots should be cut on the pine trees being cultivated in the ground. They can then be dug up in the spring.
Fruit Trees - Leaving fruit on your trees is always enjoyable, but if too many are left on the tree will be weakened. Thinning out is necessary if you want to enjoy it again next year.