-- that just might help.
John Kirby once referred to my yamadori ponderosa pine as a "happy pine!" This season, I'm afraid, it is anything but. Many new buds failed this spring: they started to grow, then died and dried up. Some buds are alive and pushing new needles, but are at least a month behind schedule. Foliage from previous years is still basically healthy, but looks "tired;" I don't know how better to describe it.
 |
| Older needles should be a more vibrant green, closer to the new needles' color (yellow polygon.) |
|
 |
| This is the strongest of this year's shoots, but the needles should be much further developed. |
 |
| A shoot that's still pushing (right) and its neighbor that has died. The closer a shoot is to the main trunk, the more likely it is to be healthy. |
|
 |
| This is how they all should look: fully-developed needles and next spring's bud already visible (yellow arrow.) This is on a nursery-bought ponderosa next to the big one. |
I'm still working to isolate the cause; the symptoms collectively point to some sort of root problem, and that's my working assumption. But meanwhile, the tree needs good supportive care if it is going to pull thru in good condition; maybe to pull thru at all. And one of those ideas occurred to me that may be brilliant and may be balmy (and you're not sure which at first.)
Compromised foliage means less photosynthesis, which means a diminished supply of sugars to fuel the tree's metabolism. (For any who don't know, a tree's cells require fuel to do
anything: multiply, repair themselves, you name it. The sugars produced in the foliage are that fuel.) Might it help, I wondered, to spray the foliage with a weak sugar-and-water solution?
Pinus ponderosa is supposed to absorb nutrients very well thru its needles.
 |
| My "supportive care kit," with the mini-sprayer loaded and ready. |
I mentioned the idea on a pair of bonsai fora. Al Keppler, another denizen of
Bonsai Nut forum, suggested molasses instead of table sugar. That makes sense to me: table sugar is just sucrose, but molasses contains sucrose, other sugars, and some other goodies besides.
So I mixed 2 tablespoons of inexpensive molasses in a gallon of water, with a short squeeze of dish detergent for a wetting agent. (In metric units: 7.8 ml of molasses per liter of water.) I sprayed the foliage thoroughly three days ago and again today; I'll repeat the treatment every two to three days until late fall. My hope is that the molasses will make up for the shortfall in the tree's own production of photosynthates -- at least some of that shortfall -- until the tree can produce a good crop of needles again. I'll also use the molasses solution from time to time when I water the tree.
Meanwhile, my investigation into the root of the problem continues. (I admit it: double-entendre intended.) Stay tuned: one way or another, I expect to at least learn something.
:-/ :-/ :-/
Steve, When many of my trees went through a similar period a few years ago the local advice to me was:Take them out of the existing pot, don't disturb the root ball at all and over-pot into pure grit. If there is a root problem don't feed. It worked. The trees responded almost immediately and are thriving now. I hope the tree survives.
ReplyDeleteMike, that's interesting. Thanks.
DeleteI've been trying to keep root disturbance to a minimum; so I've been taking out the remaining native soil a little at a time with the tree still in its box. The native soil is replaced with more of the scoria-based mix, which is very coarse and low in organic content (10%).
Come to think of it, I did essentially what you're suggesting when I got the tree 3 years ago. I left most of the native soil alone, and filled in approximately an inch of scoria mix all around it, in every direction.
But I might try what you say; have to think it over. I think it *would* be a good idea to stop feeding the roots, even with the diluted molasses.
Thanks again for the thoughts.