When to winterize

[Vinnie Charity]

You can get it on sale in the summer ;-) I typically get eight bags of it. I have about two dozen large trees.

Forgot to mention a very important thing--when you put your trees on the ground inside the shelter, make sure the feet are placed on bricks on the ground. THEN mulch them up. The air space provided by the bricks between the bottom of the pot and the ground provides an airspace so the pot can drain. Placing the pots directly on the ground is a recipe for a swamp in your pots over the winter and associated root death.

That's good to know, and mine will be resting on a concrete slab so would the bricks be overkill or still necessary?

 

[Dav4]

Haha, and where do you get your mulch @rockm? Guess I'll be heading out to Home Depot this weekend to stock up on mulch, $3 a bag isn't too bad...

Back in the day, I'd see tree guys on the side of the road chipping branches in their giant chipper and I'd ask them to dump some on my driveway or off to the side. That wood chip mulch would get spread on my perennial gardens, around my landscape trees, and on top of my potted bonsai every winter.... or you can by the bagged stuff for 2 bucks at a box store.

 

[rockm]

That's good to know, and mine will be resting on a concrete slab so would the bricks be overkill or still necessary?

If they're on concrete bricks shouldn't be necessary, but could help if the patio or whatever collects water when it's really wet, like from snowmelt that around here, can come all at once.

 

[M. Frary]

Just bought 2 bales of straw.
$4.00 each.
I'm sticking with what works for me.
Tried and tested.

 

[Cable]

Dormant trees don't need sun, and it just causes heat issues.

Evergreens continue to photosynthesize even during the winter. I wonder how much they benefit from getting sunlight in the winter vs being completely in the dark?

 

[Dav4]

Evergreens continue to photosynthesize even during the winter. I wonder how much they benefit from getting sunlight in the winter vs being completely in the dark?

Their metabolism slows down as the temps decline to the point where, if kept in the mid 30's or lower, they need no light. I overwintered pines, yews, and junipers on the floor a dark garage, frozen in wood chip mulch, for many years and they always grew strongly when brought out each spring.

 

[Leo in N E Illinois]

Evergreens continue to photosynthesize even during the winter. I wonder how much they benefit from getting sunlight in the winter vs being completely in the dark?

Technically this statement is true, BUT, in practice this statement is false. Or rather a non-issue.

At temperatures below 40 F (+4 C) the RATE of photosynthesis is so LOW that for all practical purposes it is negligible, not significant. As good as not happening at all. KEY IS TEMPERATURES MUST BE BELOW 40 F (+4 C ).

This extremely low rate of photosynthesis means that the effects of storing a tree in total darkness will not be noticeably different from providing light at the same temperature.

The average home bonsai grower has less than ideal conditions all around. From personal experience I have wintered with light and without light and saw no observable difference. I found wintering totally dark I had fewer issues with the light source heating the storage area too warm. T-5 lamps rapidly heated my cold storage area into the 50's F. Getting rid of that heat was a major problem. Old fashion T12 fluorescents did not heat the well house as much, BUT they threw so little light the trees might as well have been in the dark. Keeping trees cold enough to stay dormant is the key to successful winter storage.

IF you keep them below 40 F, there is no significant benefit to adding light. This is from EXPERIENCE, not just ''internet knowledge''. Adding light will likely create more problems with heat gain, than keeping the trees cold and in the dark.

 

[jimib]

I have learned more in this thread about overwintering than I have in 3 years of internet searching, YouTube watching and subscribing to popular bonsai sites. Thanks everyone.

 

[Cable]

Interestingly it isn't as simple as temperature. Numerous studies have been conducted that indicate conifers are able to photosynthesize at lower temperatures than deciduous with even variation within evergreen species due to needle size and shape. There is also debate whether they're really able to take advantage of warm winter days to gain extra energy. In the wild, another advantage over deciduous might be that evergreens continue to photosynthesize later in the season since they don't lose their leaves and can take advantage of the warmer temperatures in spring sooner since they don't need to regrow those leaves.

Where I work we do overwinter most container evergreens in the dark. I had never really given it a second thought until I heard Ryan Neal suggesting that evergreens should be given some light int he winter. That made me ask the question but it seems to me the temperature risk of a container plant isn't worth the possible small gain like you guys say. Was just curious.

 

[JudyB]

All the conifers that get covered in snow don’t get any light, and they come out just fine.

 

[Vinnie Charity]

Their metabolism slows down as the temps decline to the point where, if kept in the mid 30's or lower, they need no light. I overwintered pines, yews, and junipers on the floor a dark garage, frozen in wood chip mulch, for many years and they always grew strongly when brought out each spring.

I have a large wood shop in my backyard and I'm thinking of overwintering my larger trees in there as it gets colder, the thing is that they take up space that I need to work in. A shed is in order, but they aren't cheap...