Jaberwky17
Shohin
As a four year newbie, I feel like I’m starting to see results and am trying to pay attention. But something happened this past week to cause me a bit of surprise. I’m pretty sure I know the answer but thought I’d toss it out for comment and advice. I suspect that my entire collection of varying trees are suffering from root stress caused by overheating from sun exposure.
My background and setup:
I’m in NW Minnesota on the ND border – zone 4B. My collection lives on a pair of bonsai benches with great sun exposure and decent protection from rain from the deep eave above. They get great morning and afternoon sun, then lose evening sun when the eave shadow gets long. The benches are against a south-facing wall which has a light tan vinyl siding. My soil mix is a mostly inorganic, and about ¾ of the trees have this mix (adjusted slightly by species), and about ¼ are in heavy organic soils they came in until next potting season. some trees which need more protection (maples) live under the bench with dappled light.
Last season one of the small junipers I got from a Facebook auction seller arrived in fairly poor condition – browning tips and die-off starting almost immediately. The seller suggested the plant was suffering from root stress, caused by the dark pot getting too hot in the direct sun and overheating the tender roots. OK, I’ll buy that for a nickel – so I put that juni and another that seemed to be in the same boat on the bench with a large bushy pine in front. The juniper foliage got filtered sun and the pots were well-shaded. I noticed good recovery on both junipers this season so far – lots of new growth and color improvement.
Fast forward to this past week – we were going on vacation for a few days that were forecast to be in the upper 90s for several days straight. Rather than subject my trees to that heat and ask someone to come water a ton, I put everything in my attached, insulated, un-air conditioned garage on a bench. The garage has north facing windows so there is light, but not direct. Upon our return after 4 days in the garage, almost every tree, regardless of species, showed tremendous growth. The cotoneaster had 2”+ shoots, all junipers had way more healthy growing tips, the elms had 3,4, even 5 pairs of leaves on new shoots. The black pine second growth candles were noticeably longer. Everything was super happy.
I think it’s clear that my trees are enjoying the cooler pot temps but I was surprised to see THAT dramatic of a change in ALL the trees. My question becomes – how to set up my outdoor space to prevent the overheating but still allow the necessary sun exposure that some of these trees require? Am I missing something or is happier/cooler roots the likely effect of what I’m seeing?
My background and setup:
I’m in NW Minnesota on the ND border – zone 4B. My collection lives on a pair of bonsai benches with great sun exposure and decent protection from rain from the deep eave above. They get great morning and afternoon sun, then lose evening sun when the eave shadow gets long. The benches are against a south-facing wall which has a light tan vinyl siding. My soil mix is a mostly inorganic, and about ¾ of the trees have this mix (adjusted slightly by species), and about ¼ are in heavy organic soils they came in until next potting season. some trees which need more protection (maples) live under the bench with dappled light.
Last season one of the small junipers I got from a Facebook auction seller arrived in fairly poor condition – browning tips and die-off starting almost immediately. The seller suggested the plant was suffering from root stress, caused by the dark pot getting too hot in the direct sun and overheating the tender roots. OK, I’ll buy that for a nickel – so I put that juni and another that seemed to be in the same boat on the bench with a large bushy pine in front. The juniper foliage got filtered sun and the pots were well-shaded. I noticed good recovery on both junipers this season so far – lots of new growth and color improvement.
Fast forward to this past week – we were going on vacation for a few days that were forecast to be in the upper 90s for several days straight. Rather than subject my trees to that heat and ask someone to come water a ton, I put everything in my attached, insulated, un-air conditioned garage on a bench. The garage has north facing windows so there is light, but not direct. Upon our return after 4 days in the garage, almost every tree, regardless of species, showed tremendous growth. The cotoneaster had 2”+ shoots, all junipers had way more healthy growing tips, the elms had 3,4, even 5 pairs of leaves on new shoots. The black pine second growth candles were noticeably longer. Everything was super happy.
I think it’s clear that my trees are enjoying the cooler pot temps but I was surprised to see THAT dramatic of a change in ALL the trees. My question becomes – how to set up my outdoor space to prevent the overheating but still allow the necessary sun exposure that some of these trees require? Am I missing something or is happier/cooler roots the likely effect of what I’m seeing?
