We are certainly living in interesting times, with most of us confined mainly to home as a result of COVID-19. What a great opportunity to get out among your trees and give them the attention they have possibly lacked over the very hot summer months.
Most of us have probably lost at least a few of our bonsai this year, due to the punishing conditions. I myself have lost several, sadly. I find it best to dispose of dead trees quickly and rearrange the remaining trees to fill in any empty spaces on the bench. This helps me not to fret over what I have lost, but rather to focus on what I have left.
While the weather remains warm, it’s a good time to repot many species, particularly evergreens like pyracantha, cotoneasters, olives and star jasmine etc. Recently repotted trees will need protection if the nights suddenly become cold within the first couple of weeks after repotting.
It’s a good idea to tidy up conifers as well. Remove any dead or overly dense foliage on junipers and reduce the needles on species such as pines or cedars by removing any that are on the undersides of branches. New shoots on these species normally only grow from locations on the branches where there are needles, and you don’t normally want new shoots growing straight up or down, but rather, sideways. Remove unwanted candles as well on pines, leaving no more than two at any junction.
Now it is too late to prune back figs; they should be left until the warmer spring weather returns later in the year. While the weather is still warm maximize the amount of sunlight they receive, but if the nights become cold move to a more sheltered spot.
Keep fertilising to build up strength for your trees to handle the colder months ahead. Keep using low nitrogen food to prevent a rush of soft new growth as this may be damaged over winter. Feeding of deciduous species is particularly important to maintain health in the tree over the winter dormancy. Sunny days and cool dry nights will hopefully enable maples and liquidambars to show a lovely display of autumn colour before the leaves fall.
Autumn is a good time to do any wiring on trees, as the tree’s growth is generally slower over autumn/winter and the wire can be safely left in place for longer. Wiring done in spring, on the other hand, needs to be constantly checked, or unsightly cutting in can happen alarmingly quickly.
Watering can most likely be reduced at this time, as the heat of the sun has eased off somewhat, but be alert nonetheless, particularly if it suddenly becomes windy. Recent rain and still weather has probably made intense watering unnecessary already. It’s still important not to allow your trees to dry out.
Last but not least, keep up with the weeding! Remember it’s your trees you want to nurture, not the weeds!