Has anyone ever used the technique of "Dome Growing" where you have a plastic bag over the top of the plant or a plastic dome to hold in humidity? I used this method with a squirt bottle to replenish soil wetness and humidity and it worked really well.
I put plastic bags over pots of cuttings to keep them from drying out before they're well rooted. It's tricky getting the water right. Too much and they rot. Too little and they die.
If I'm going out of town for a couple of weeks I'll put my african violets into bags so they won't dry out. Keep them out of full sun though, or you'll bake them.
If you have trouble with dry air affecting your plants in the winter, the domes, aquariums or plastic bags would help alot.
Wouldn't it be smarter to make your own with a plastic bag or something rather than buying one? I have tried the plastic bag approach and it worked very well for replenishing the humidity so I would say just do that.
So far, I've had great success with using the top 3/4 of 2 or 3 liter bottles and plastic milk jugs. They also make great mini greenhouses for starting seeds and small cuttings.
With the liter bottles I cut them in two just above the area where the bottom of the bottle shape blends into the side of the bottle. This gives me a bit of round top on the bottom half. You can cut away 2 or three small V-notch sections of this part and then do the same of the bottom of the top half. You can then either set the top over a plant in a pot or put a potted seedling in the bottom half of the bottle. You'll need to overlap the top half over the bottom to secure it in place. Just rotate the bottle so the vented cuts line up. You want to make sure you get some fresh air for the plant. A small piece of tape works great to secure the top to the bottom.
I use this same cut and vent format with the translucent milk jugs. plants seem to grow in these just as well as the clear sided bottles. When the bottles wear out, just recycle them.