treebeard55

Many of us have gotten this idea from Carl Rosner of New Jersey. I'm not sure if it's original with Carl, but I sure do appreciate knowing about it. It's simple and inexpensive, and is an effective way to keep up the humidity around a tree recovering from almost anything. Hopefully, someone else will also find it helpful.

1. Take a cardboard box, large enough to fit over the tree with a few inches' clearance all around.
2. Cut off the top flaps, and flip the box over.
3. Cut "windows" in what is now the top and in all 4 sides, so it looks like my quick-and-dirty virt. (But please try to make your cuts straighter than my lines!)
4. Cover the windows with something transparent. I recommend polyethylene sheeting, which in the US is sold in paint stores for drop cloths. Polyethylene has been shown to pass oxygen and carbon dioxide, but not water vapor. Make sure it's polyethylene, and get the thinnest you can find.
5. Tape your window material in place, and tape all around the edges for a watertight seal.
6. Water the tree, mist it thoroughly, and put it in bright light (but no direct sun) with the ICU over it.

Attached Images

Rosner ICU virt.jpg (70.5 KB, 3 views)

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Treebeard 55
Steve Moore
http://hoosierbonsai.blogspot.com

The most important bonsai tool is your brain.

JLDoggett

Nice virt, Tree, and good directions.

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mage973

Great invention!

"Hopefully, someone else will also find it helpful."

I certainly did so, thank you!

I was resorting to blowing up a large clear plastic bag with a tree inside and tying the bag shut. It worked, (my tree has started to grow again with the increased humidity) but keeping the leaves from resting on the bag or the bag bending the branches was an issue and it just wasn't pretty. Plus I had to blow up the bag with each watering.

Then I saw your post and I made one of your Humidity ICU things this morning for my barbados cherry! I put the plastic on the inside the box so the cardboard wouldn't get soggy. Water is starting to condense already (5 or so hours) so Kudos to you! You saved a tree!

mage973

How about the plastic used to cover/seal windows in the winter?

Could glad bags, zip loc bags, cling wrap be cut and used?

I'm not sure what kind of plastic they are or if they pass oxygen and carbon dioxide. I'm just thinking of what someone might already have around the home. Just wondering?

treebeard55

Glad it works well for you, Mage. But thank Carl Rosner, too: he came up with the idea.

Yeah, anything that transmits light could be used for the "glazing." The advantage of the polyethylene is that you don't have to lift the ICU off for 30-60 minutes a day to allow air circulation. But if you have Saran wrap and want to use it (grabbing an example out of the air,) go ahead. Just make sure the air gets refreshed daily, or you may have trouble with fungus and mold.

__________________
Treebeard 55
Steve Moore
http://hoosierbonsai.blogspot.com

The most important bonsai tool is your brain.