I don't know if this would be logical at all or not. Could you dissolve a fair amount of dry ice into a bucket of water therefore releasing the C02 into the water and then use that water on an outside plant to boost c02 levels and benefit the plant?
ummmm short answer:dont long answer: the plants roots need to take in O2 from the soil so watering with CO2 would probably 'drown' the plants. although if you hung bucket of dry ice above your plants, however impractical it may be, you would get some extra CO2 into your buds. you see, the plants breath CO2 in from under the leaves, and exhale O2 through the same area. the roots however, need oxygen that they then suck up into the plant to make sugars, etc. i would advise against it, but if you want to waste a bagseed or something, try it out.
I smoked away most of my 8th grade year, but I can vaguely remember that dry ice releases CO2. I remember us putting balloons over test tubes with water and dry ice in 'em. This actually seems like a great idea though, putting some around the plants. I need to try this sometime .
Thanks for the info hitmanbob. I think that I may try it on one of my smaller plants just to check out the results, but it sounds like a good idea to hold of on the others. I'll hit you guys back and let ya know how it turns out. Also i didn't think they would benefit much from dry ice around the plant with it being out doors and all, i think the wind would quickly move whatever c02 was released into the air