Hello,
I was wondering if anyone can provide experience on growing Juniperus squamata in the tropics. Matthew already indicated they did very well during his stay in Rocky - can anyone else provide any further examples of experience?
regards
Ash
Juniperus squamata in the tropics?
-
Woody11
- Aussie Bonsai Fan
- Posts: 28
- Joined: October 31st, 2010, 4:36 pm
- Favorite Species: Japanese black pine
- Bonsai Age: 5
- Location: Gold Coast
Re: Juniperus squamata in the tropics?
Hi Ash
I grew junipers and pines in Townsville for two years and Mackay for one. Despite what I had been told would occur, I had no problems. What worked for me is well drained potting mix and ensuring the trees got enough light without the sun cooking the roots.
My mix was typically locally sourced 5mm quincan rock (which is actually black/grey scoria for those down south) with 5mm composted pine bark. This was mixed in varying ratios but was typically 3 parts quican rock to 1 part bark. If bark was unavailable, I just used some coarse good quality potting mix. Potmate by Debco was ideal but they stopped selling up north during my time there. Made the mistake of using a fine texture potting mix and it just clogged my drainage. One thing I did make sure I avoided was any potting mix with water saving crystals in it. They just swelled in the during the constant rain of the Wet and made a terrible mess. I also avoided adding sand to my mix as it seemed to clog up the drainage for me. With this mix, I was happy to let the trees get rained out for several days in a row, but if it went for too long , they got placed under cover in a well ventilated and bright position. I never used antifungal treatment at all and rotting was not a problem. I lost two junipers but that was due to me pinching out the new growth routinely, advice which was well circulated for a long time but now is being seriously questioned. I felt that the increased porosity of the mixes I used helped avoid root rot by increasing oxygenation. The downside was you had to be careful to water more regularly. But I didn't have the hassle and safety issues with sprays etc. I wished I could get scoria/quican rock on the Gold Coast now at the appropriate size. I actually liked it more than diatomite. Downside was it was mighty heavy for grow on pre-bonsai stock.
I have seen many growers try and place their trees in the shade or filtered light for fear of the tropical sun. I can see their point but I begged to differ. My trees were placed in good light for 6 hours a day. They sat on weldmesh benches which helped maintain air circulation and meant the pots were not exposed to prolonged heat post-sunset from heated surfaces (e.g. concrete, wooden benches). It also meant things drained well without water sitting around the trees. As the mix dried, the water evaporation seemed to keep the pots slightly cooler by latent heat of evaporation (i.e. like the old Coolagardie safe). I figured that by getting the trees good light, they could photosynthesise and keep actively growing. It was a method which seemed to work. I aimed for bright conditions but without necessarily wanting direct sun. That may sound like a contradiction I admit. I'm not sure how best to explain it otherwise. Alternatively, I had considered placing smaller pots which would normally struggle to stay cool in the heat, in styrofoam boxes. The pots could be covered with coarse pine bark and insulated. It's a technqiue I never actually used but I often wondered whether I would be good to try on shohin and mame trees.
I found that some of the advice regarding potting time had to be adjusted for local conditions up north. I liked repotting in the period from March to June. That way the roots grew in more favourable cooler dry conditions. Repotting after October risked new growing roots being exposed to heat, humidity and rain. I felt that was going to make it hard to avoid root rot.
Anyway, hope that helps.
Woody
I grew junipers and pines in Townsville for two years and Mackay for one. Despite what I had been told would occur, I had no problems. What worked for me is well drained potting mix and ensuring the trees got enough light without the sun cooking the roots.
My mix was typically locally sourced 5mm quincan rock (which is actually black/grey scoria for those down south) with 5mm composted pine bark. This was mixed in varying ratios but was typically 3 parts quican rock to 1 part bark. If bark was unavailable, I just used some coarse good quality potting mix. Potmate by Debco was ideal but they stopped selling up north during my time there. Made the mistake of using a fine texture potting mix and it just clogged my drainage. One thing I did make sure I avoided was any potting mix with water saving crystals in it. They just swelled in the during the constant rain of the Wet and made a terrible mess. I also avoided adding sand to my mix as it seemed to clog up the drainage for me. With this mix, I was happy to let the trees get rained out for several days in a row, but if it went for too long , they got placed under cover in a well ventilated and bright position. I never used antifungal treatment at all and rotting was not a problem. I lost two junipers but that was due to me pinching out the new growth routinely, advice which was well circulated for a long time but now is being seriously questioned. I felt that the increased porosity of the mixes I used helped avoid root rot by increasing oxygenation. The downside was you had to be careful to water more regularly. But I didn't have the hassle and safety issues with sprays etc. I wished I could get scoria/quican rock on the Gold Coast now at the appropriate size. I actually liked it more than diatomite. Downside was it was mighty heavy for grow on pre-bonsai stock.
I have seen many growers try and place their trees in the shade or filtered light for fear of the tropical sun. I can see their point but I begged to differ. My trees were placed in good light for 6 hours a day. They sat on weldmesh benches which helped maintain air circulation and meant the pots were not exposed to prolonged heat post-sunset from heated surfaces (e.g. concrete, wooden benches). It also meant things drained well without water sitting around the trees. As the mix dried, the water evaporation seemed to keep the pots slightly cooler by latent heat of evaporation (i.e. like the old Coolagardie safe). I figured that by getting the trees good light, they could photosynthesise and keep actively growing. It was a method which seemed to work. I aimed for bright conditions but without necessarily wanting direct sun. That may sound like a contradiction I admit. I'm not sure how best to explain it otherwise. Alternatively, I had considered placing smaller pots which would normally struggle to stay cool in the heat, in styrofoam boxes. The pots could be covered with coarse pine bark and insulated. It's a technqiue I never actually used but I often wondered whether I would be good to try on shohin and mame trees.
I found that some of the advice regarding potting time had to be adjusted for local conditions up north. I liked repotting in the period from March to June. That way the roots grew in more favourable cooler dry conditions. Repotting after October risked new growing roots being exposed to heat, humidity and rain. I felt that was going to make it hard to avoid root rot.
Anyway, hope that helps.
Woody
