Author Topic: Weak/yellow spring growth  (Read 1124 times)

Josh

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Weak/yellow spring growth
« on: February 20, 2014, 07:32 PM »
I recently repotted several well established larch, as buds were swelling.  Repotting not aggressive.  Now in dark garage, 45 degrees.  Buds opening to light yellow tufts, historically much more green.

QUESTION: Is the light/yellow new larch foliage due to lack of light?  Is sunlight needed to produce chlorophyll/yellow color?  Is it dangerous to keep in dark longer?  Can go to heated greenhouse, but wanting to slow the trees down. 
 

Dan W.

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Re: Weak/yellow spring growth
« Reply #1 on: February 20, 2014, 08:03 PM »
If the tree is opening buds it needs light. A bit late to slow the tree down now, in my opinion. Yes, the weak growth would be due to a lack of light.
 

Dan W.

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Re: Weak/yellow spring growth
« Reply #2 on: February 20, 2014, 08:06 PM »
I would adjust it to light slowly at this point though. A cold greenhouse like you mentioned should work.
 

Leo in NE Illinois

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Re: Weak/yellow spring growth
« Reply #3 on: February 23, 2014, 11:16 PM »
45 F is too warm to keep larch dormant. Temps really need to be colder than 39 F, and larch are quite happy right down through -20 F. They are very hardy trees, adapted to grow in cool, short growing seasons. If the buds were swelling, you stored them too warm. Your profile says you are in zone 4, you should really have stored them outside, exposed to much lower temperatures to keep them dormant so that when they break dormancy, than can be outside to get full sun.

Given that, when the buds swell is the right time to repot. AND after repotting, you can not put them back into sub-freezing temperatures, so the greenhouse is the best option.

I am in zone 5, and discovered I get much better results with all my zone 5, 4 and 3 hardy trees if I keep them outside under the benches, with no effort to keep them warm. Just keep them out of the wind, and shaded from the sun. So I put them under the growing bench, pile on leaves and snow, and tarp the  bench to block the wind. That way nothing breaks dormancy until it is time to break dormancy in my area. I have successfully wintered an American larch on top of my bench, with no protection. It was young and in a plastic pot, went through fine, did not even get winter sun scald. But usually I do move them under the bench, so they are protected from the dehydration of the sun and wind.