The leaves take in carbon dioxide (CO2) and give off oxygen. The roots take in oxygen and give off carbon dioxide. I would think that leaving the bag open or partially open would certainly be a benefit to the cutting. - Millet

it is true that in most plants, there is a net CO2 production during the night time but this is miniscule net production, and often times stored as acids and so could not often be measured as net output. The CO2 are actively taken up during the day when there is photosynthetic activity and utilized those that are stored up and also will absorb most CO2 from the air.

There are some types of plants in the extreme case called CAM plants that takes up and aborb most of the Carbon Dioxide during the evening. While they themselves produce such carbon dioxide, they reabsorb it and store as acids. They close their stomates during the day to minimize water and process the captured carbon dioxide the night before and during the day separates them from the acid and use those for photosynthesis. They store the carbon dioxide into acid, that is why this is called Crassulacean Acid Metabolism (CAM), and thus the name CAM plants. Examples are most cacti and pineapples. Citruses are mostly C3, corn and most grasses are C4. Some plants uses mixed carbon fixation pathways, like it could switch mode between C3 and CAM, ie, pineapples.

I have kept zipper baggies open and have kept them sealed.. when I keep them sealed I usually air them up daily by blowing in to them. This adds co2 and keeps the sides of the bags off the leaves of the plant.
I did blow this baggie up fo this pic but it winded me pretty good and I have not done it again since.. I keep this bag slightly open..
I took the plants out of the baggie and wrapped it in some lights I found to warm it up as I was worried it was getting too cool for them.. which proved to be disasterous. warmed up and no bag to protect them they dried out. I have put them back in the bag and am less worried about them getting too cool. They look terrable now.. Time will tell.. but I think I might have lost at least a couple of them..
Gina *BabyBlue*

How are the cuttings that were in the Whitcomb system doing? This the show much better root structures? Did they grow faster than those in the peat pots?
Andi

I have had a bit of troubles keeping them properly moist.. They dry out very quickly with all the holes..
I did some plant house cleaning today and have dumped out all the pots of plants that haven't made it..
I am not sure what to do..
They were doing much better when I had them kept in the XXL zipper baggie.. I took them out of that and they died very rapidly after that.

But I have much bigger fish to fry right now.. having some freak soil issues.. and the dang sick bug has circulated my family twice now.. not a day with out someone sick in the past month..
I'm off to post about my freak soil issues..
Gina *BabyBlue*

Hey stranger, sorry about your seedlings & everyone being sick. I caught a bug last Nov/Dec & all this time I thought it just was a reg. cold. I got meds for bronchitis now, so should knock it out soon I hope. Been sick all winter ...C'MON SPRING!!!!
Gina, don't throw all that soil away. You can sterilize it. I know this will sound weird, but I put old soil in a large roasting pan & bake it for 1/2 - 3/4 hours in oven at 350 -375*. It WILL STINK, so turn your exhaust fan on! Much cheaper than buying new soil mix. It really works!

I plant all my seeds in a tray covered with a dome or saran wrap. Some bottom heat helps, or sun from a sunny window. I only water from the bottom to keep them from damping off. The baggie method works good to germinate, but it's hard on them when time to transplant, so I don't do that.