Updated: Jan 7
There is often a short coming of Bonsai teaching and that is the use of seasons as an indicator for timing of techniques, there is an obvious flaw in this though as its not actually the season it self that allows us to perform certain techniques but rather the unique weather conditions. This means that for most people the timing of these techniques can be very different, Lets discuss a few examples.
Todays article wont be super long and extensive but its content might actually save a few of your trees. We have all heard things like we Re-Pot late winter / Early Spring or we do post harden prune late spring / early summer etc etc. But the problem is a lot of the time we are taught this timing through the use of season and not the actual triggers within those seasons that allow that work to be done, People in 2 neighbouring states might Re-Pot at 2 completely different times even though they are in the same season. I can re-pot 2 -3 weeks earlier then people i know who are only an hour and a half away from me.
Lets take a look at Re-Potting as the main example, like above we have all heard the theory that we Re-Pot late winter / Early Spring. Now this is all well and good but that only if you season changes right on cue and allows the triggers we need for that work to be done. For example end of winter is usually our deciduous trees, the reason for this is we want to wait for signs of metabolic activity to start to let us know the tree is active and waking up, we don't want to re-pot to early while the tree is still dormant because it wont actively repair the roots that have been cut and the longer those wounds are open the more chance of disease setting in. So we wait to see the signs of bud swelling which tells us the tree is waking up and is active but the tree isn't fully transpiring yet so this allows us a window of opportunity to get the trees root work done and we will still have 14 days for the roots to be repaired before the foliage fully opens up and starts needing to move water at a rapid rate. Now this activity in the tree can be different even in the same garden, some trees start to wake up earlier then others and some later, this can be an even bigger difference between 2 different climates, warmer climates the trees might start to wake up before the last month of winter, in cooler climates the trees might not begin to wake until the early weeks of spring. This depends on warmth and daylight. So you can see that following the end of winter / early spring method is really no good, you need to understand the actually reasoning behind those timings.
The same can be said for evergreens and conifers when it comes to re-potting, usually here in my climate i try and wait till over night temperatures are somewhere between 14 - 16c overnight, Because we know that roots grow during the night and a requirement for roots to begin growing properly is warmth, so if overnight temps are still low and i begin repotting my conifers and evergreens the roots might not grow and repair as quick as i would like them too. Now if your in a much cooler environment you also need to watch out for sudden cold snaps. I've known of places having nice warm weather for the first few weeks of spring then a sudden overnight cold snap back down to 0c. This could be the death of a freshly re potted tree. so understanding your environment properly is key. The people in these kind of environments might need to wait a few extra weeks or have a green house set up to house the trees for up to 2 weeks after re-potting for protection.
Now i know this was just one example but if you can start thinking like this for all techniques that are described as a season for timing then you will be better able to understand the work. Try and understand what in that season allows that techniques to be performed, is it day light houses, is it temperature? is it a certain action the trees takes in that particular season? take large bends for example, Autumn allows us to get this done because the weather is starting to cool to a temperature that is not too hot and not too cold so the tree isn't under temperature stress, but also autumn is the time where the new layer of cambium that was grown over the growing season hardens off which allows us to really crank on it without it splitting too much, if we do this during spring and summer while that cambium is still fresh and fragile we could completely severe it causing the branch to die.
So as you can see todays articles wasn't super technical but more of a mindset lesson that will allow you to better apply techniques based of actual knowledge of the technique and the species of tree you are working with. This could be a massive step up for your work and help your trees have a better survival rate when it comes to work, this is especially true for repotting, if we don't understand this process from both the techniques point of view and the horticultural point of view this is usually the techniques that people lose their beloved trees too.
Until Next Time, Enjoy Your Bonsai Journey.