GreatBasinBonsai
Seedling
I have been collecting some Curl-leaf mountain mahogany, and after 20 years or so I'm beginning to have some success, but generally in the second or third year post collection they start to get brown/yellowish leaf tips, see the picture below.
I suppose overwatering and overfertilization could cause these issues, and I'm doing my best to avoid either. But I feel like there's a kind of catch 22 situation developing that bedevils me. Which is this: I have to leave a good ball of field soil or the trees 100% die. However, the field soil retains a lot more water than the large grain pumice i pot them in post collection. I water about every 1-2 days in summer, every time the top inch or so of pumice has dried out. But I wonder if the small amount of new roots growing into the moat of pumice aren't too wet, while the lions share of roots (still in the field soil) are drowning. And possibly causing the yellowing/browning tips?
Or, perhaps ANY amount of fertilization at all (I only use a very small amount of organic fertilizers) is initially too much for these nitrogen fixing desert dwellers, which survive on very very little organic matter in the wild. Am I perhaps burning them?
What would be fantastic is if someone has a link to, say, some kind of scientific explanation of leaf tip yellowing and browning and all the possible potential causes and WHY they occur. I wish I could have some kind of plant-physiology college course deep dive into this stuff!
I sometimes feel like it's a delicate race against time to remove the field soil before it chokes them out in the long, complex "domestication" process…
Anyway thanks so much! Hope I explained well. Really appreciate any light that could be shed on this situation…
I suppose overwatering and overfertilization could cause these issues, and I'm doing my best to avoid either. But I feel like there's a kind of catch 22 situation developing that bedevils me. Which is this: I have to leave a good ball of field soil or the trees 100% die. However, the field soil retains a lot more water than the large grain pumice i pot them in post collection. I water about every 1-2 days in summer, every time the top inch or so of pumice has dried out. But I wonder if the small amount of new roots growing into the moat of pumice aren't too wet, while the lions share of roots (still in the field soil) are drowning. And possibly causing the yellowing/browning tips?
Or, perhaps ANY amount of fertilization at all (I only use a very small amount of organic fertilizers) is initially too much for these nitrogen fixing desert dwellers, which survive on very very little organic matter in the wild. Am I perhaps burning them?
What would be fantastic is if someone has a link to, say, some kind of scientific explanation of leaf tip yellowing and browning and all the possible potential causes and WHY they occur. I wish I could have some kind of plant-physiology college course deep dive into this stuff!
I sometimes feel like it's a delicate race against time to remove the field soil before it chokes them out in the long, complex "domestication" process…
Anyway thanks so much! Hope I explained well. Really appreciate any light that could be shed on this situation…
