Help! Insane amount of mold on all of my trees in coldframe :'(

[TheEmpireNeverEnded]

Title says it all. Built a dark box to overwinter my trees here in PA to these exact specifications (https://bonsaiwonders-art.blogspot.com/2009/08/building-cold-frame.html) with the exception of the windowed lid. The inside is staying waaaayyy to moist and when I went to check on it yesterday, everything was covered in white fuzzy mold. This includes the tips of the branches on many of the trees and the surface of the mulch.

I basically made a mold factory: a dark warm moist box full of nutritious decay.

Is there anything that I can do to treat the stuff? Can anyone point me in the direction of the best chemical fungicide or something that I can coat everything with? This is my first winter (and it has been wayyyy warmer than previous years by this point (Pittsburgh's wettest december on record)).

I can easily imagine all of my trees dying to this. THIS IS A LOT OF MOLD. I AM NOT EXAGGERATING!

Anyway if anyone could help me/offer adept guidance, it would be you all. Please do. I would appreciate any information, because I probably need to take action of some sort really soon.

 

[coh]

Show some pics if you can get some.

Open that thing up and air it out. Other than around Thanksgiving and a couple of days in December, it really hasn't been all that cold (though that depends on what kinds of trees you have). My winter storage areas have only been completely closed up for a few of the colder nights, I'm keeping them open as long as the weather allows.

 

[Mike Hennigan]

My suggestion would be to take all the trees out of the cold frame, buy some pinebark mulch or similar somewhat coarse mulch, set the pots on the ground on the north side of your house where they’ll be in mostly shade and mulch over and around the pots. That should be more than sufficient winter protection for the trees as long as they are hardy to your zone.

Last winter I had all this white mold stuff growing inside the mulch that I had mulched my trees in with. But all the trees we’re fine. I have no idea if that mold is harmful or not, but if you want to be safe mulch them in outside of your coldframe.

 

[coh]

My suggestion would be to take all the trees out of the cold frame, buy some pinebark mulch or similar somewhat coarse mulch, set the pots on the ground on the north side of your house where they’ll be in mostly shade and mulch over and around the pots. That should be more than sufficient winter protection for the trees as long as they are hardy to your zone.

Last winter I had all this white mold stuff growing inside the mulch that I had mulched my trees in with. But all the trees we’re fine. I have no idea if that mold is harmful or not, but if you want to be safe mulch them in outside of your coldframe.

I think you'll find mold growing in just about any mulch pile. I did the mulching thing one winter (never again - required way too much mulch and way too much time/energy to move it!) and the mulch had a lot of mold in it but the trees were fine. But they weren't closed up in a tiny box, they were on the floor in my rather airy barn.

 

[garywood]

Darth, humidity is high and not enough air movement or fresh air exchange. If temps aren't low the containment should be open to air movement.

 

[Mike Hennigan]

I think you'll find mold growing in just about any mulch pile. I did the mulching thing one winter (never again - required way too much mulch and way too much time/energy to move it!) and the mulch had a lot of mold in it but the trees were fine. But they weren't closed up in a tiny box, they were on the floor in my rather airy barn.

I acquired a fair amount more stock this season, and mulching all of it in was a major pain this year. Not too bad last year. Really started me thinking I should get an attached garage... ?

 

[TheEmpireNeverEnded]

Thank you all for the responses. I think my primary mistake must have been keeping the lid shut since thanksgiving. I'll post some photos tomorrow so you can glimpse the gore.

It is the mold on the tree limbs themselves which really has me worried.

 

[coh]

Thank you all for the responses. I think my primary mistake must have been keeping the lid shut since thanksgiving. I'll post some photos tomorrow so you can glimpse the gore.

It is the mold on the tree limbs themselves which really has me worried.

I've never had that happen so I don't know what to do about it (other than ventilation). I open my shelters up whenever possible during the winter for aeration. Some winters they're closed for weeks at a time, maybe even a month. But most years there are enough breaks to get them aired out. None of my shelters are really air tight either but when they're closed up for long periods I do get condensation on the walls and ceiling that will freeze.

 

[TheEmpireNeverEnded]

I've never had that happen so I don't know what to do about it (other than ventilation). I open my shelters up whenever possible during the winter for aeration. Some winters they're closed for weeks at a time, maybe even a month. But most years there are enough breaks to get them aired out. None of my shelters are really air tight either but when they're closed up for long periods I do get condensation on the walls and ceiling that will freeze.

Mine is experiencing a ton of condensation on the walls and ceiling at all times. What temperatures do you close yours/keep yours open for? What nightly lows cause use to seal them up?

 

[TN_Jim]

you got pics?
pull & clean em’ off if you’re really worried
it’s a humidor in there I’m guessing too -let em breathe

 

[Potawatomi13]

"set the pots on the ground on the north side of your house where they’ll be in mostly shade"

Why? Personal trees here fully exposed to any ambient sun.

 

[jeanluc83]

"set the pots on the ground on the north side of your house where they’ll be in mostly shade"

Why? Personal trees here fully exposed to any ambient sun.

To keep them cold as long as possible in the spring. In the Northeast we commonly get periods of warm weather in the 50s and 60s followed by cold in the 20s or teens. If the trees are allowed to warm up early they will break dormancy too soon.

 

[Rabe]

If there is a lot of mold you got a lot of spores too. Even if you let fresh air in. I would get them out, clean them (as far as you can) and the box. Then fill the box with fresh mulch or bark and let the lit open and pull over a sheet that can cover it in case of rain.

 

[Dav4]

Cold frames only work well when it's cold, as in below freezing. Personally, I've never used a cold frame, but if I did, I would want my trees to be sitting in frozen soil/mulch before closing the top. The idea isn't to prevent them from freezing, but rather to keep them cold/frozen- but not too cold- through the winter. If they aren't frozen, I'd keep the top open or else you're going to have moisture issues and early bud break.

 

[Wilson]

Definetly pull them out, and spray them clean. As @coh mentioned, what type of trees? Even up here in Québec it has been very warm, we don't even have snow on the ground. I have never had my trees enclosed with a roof, just fencing for the dogs!

 

[coh]

Mine is experiencing a ton of condensation on the walls and ceiling at all times. What temperatures do you close yours/keep yours open for? What nightly lows cause use to seal them up?

So...this is what I do. It works for me.

I don't leave trees outside. Too many variables that I cannot control - varmints (we live in farm country with a lot of mice, voles, rabbits, etc), erratic snowcover and weather conditions. I don't want to bother with burying trees in mulch (too much work, still have to worry about varmints). Any time I've left trees outside (usually nursery stock) I've had animal damage.

I'm lucky to have an attached but uninsulated garage with some space, and a large barn. So I built storage shelters inside both, I framed out small shelters (10x10' in my barn, smaller in the garage) and covered them with a couple of layers of plastic. The trees go inside on tables. This leaves the pots and roots fully exposed to whatever the air temperature is, so in the barn shelter I use a thermostatically controlled space heater to maintain the temp at about 27-28 F. In the garage I use seedling heat mats to keep the temperature close to that range. Sometimes during long/extreme cold spells it gets a little colder but not by much.

So I'll usually close up the shelters when I expect the temp to get down to the mid 20s. Since both shelters are indoors there is a buffering effect - in other words, the outside air temp might get down to 20 but it won't go below 25 or 26 in the shelter. In your case your shelter is outside so you'll have to figure out what works for you - the temperature ranges will be more extreme than what I get in my barn or garage.

As others have mentioned, the goal is to get the plants cold and keep them that way. You should get a thermometer and put it inside the shelter, preferably one of the remote reading ones. That way you can keep an eye on the temperature. If the temp inside the cold frame is the same as the outside temp (or higher), there's really no reason to have it closed - you need the ventilation to prevent the kinds of problems you're encountering.

I hope that helps but every situation is different. Let us know what kinds of plants you have. Good luck!

 

[sorce]

Seems collecting them all in one place is the Best Invite for V.C. (critters.)

The ONLY VC terrors I ever read of were when bunched, or "wintered".

It's because we create a smorgasbord for the little fuckers. They are creating an "eat and bang" around our trees...an environment they Don't get otherwise. All the trees get eaten, not because one mouse found it's food, but because by the end of the season there are 40+ hungry inbred VC in the shelter.

This environment isn't possible with ONe tree alone on the ground.

So if the tree doesn't need protection....don't protect it!

100% is only possible 2 ways.

1. Very Healthy Local Material Unsheltered.

2. Anything else in a Professionally Climate Controlled Greenhouse..... with Cats...cats that don't knock small trees over...yeah...skip the cats!

Sorce

 

[Japonicus]

Seems collecting them all in one place is the Best Invite for V.C. (critters.)

The ONLY VC terrors I ever read of were when bunched, or "wintered".

It's because we create a smorgasbord for the little fuckers. They are creating an "eat and bang" around our trees...an environment they Don't get otherwise. All the trees get eaten, not because one mouse found it's food, but because by the end of the season there are 40+ hungry inbred VC in the shelter.

This environment isn't possible with ONe tree alone on the ground.

So if the tree doesn't need protection....don't protect it!

100% is only possible 2 ways.

1. Very Healthy Local Material Unsheltered.

2. Anything else in a Professionally Climate Controlled Greenhouse..... with Cats...cats that don't knock small trees over...yeah...skip the cats!

Sorce

Good video Sorce. I pretreated my area under my sunroom for these varmints as well as insects
and will be moving my trees in over the next 3 weeks hopefully, as well as following up
with a dormant oil spray.
@TheEmpireNeverEnded I lost 75% of my collection in my 1st and last cold frame
roughly 15 years ago. Not due to mold and damp conditions, rather transpiration, and heat.
Can't blame the cold frame, just the improper use of the cold frame.
Still, had I not used the cold frame, I would have some very nice conifers now, that I don't have.

I seem to have missed what kind of trees, roots and foliage you're protecting with this contraption.

 

[TheEmpireNeverEnded]

My trees are as follows: two trident maples, an amur maple, a kotohime, an american hornbeam, two american elms, a canadian hemlock, a river birch, and a tiny juniper procumbens nana. Just a random assortment that I've collected this year.

Slideshow time. Sorry for the number of pics Upon cracking the lid today, I was delighted to find that my panic might have been greater than what was warranted, regarding the magnitude of the mold. That, or the mold has somewhat subsided from a few days ago when I first noticed it. It was still coating the American Elm in the big black pot (and I just ended up removing that whole tree from the box because it had literal black mold on it). My kotohime was also very moldy on the tips of the branches, so I pulled that out and hosed it down and removed all the dead leaves. I took out the dead leaves in general that had accumulated in the box. Now I'm debating whether to remove the mulch entirely, or just keep the lid up until it freezes. I'm thinking about building a temporary rodent screen lid for it while the actual lid is off. Regarding critters, The whole box is lined with steel screen that generously overlaps and the lid is quite snug. Now that it is going to be sitting open, I definitely run the risk of mice etc. moving in. Should I take the mulch out entirely and just let the trees sit in the box? Does the mulch make that much difference considering the box already stops wind/is a foot or two below ground etc. Could the trees just sit on the metal screened bottom, which is itself above four inches of gravel?

 

[TheEmpireNeverEnded]

The rest of the photos...