Today, I received a constructive comment of Charles ASH on my former posting :
(J. TOLLEDOT / Willem) August 1, 2007
“Some years ago we used to grow loads of plants in used transparent bottles, here in England, with great success. No real problem with algae. But if left in strong sunshine, the roots that where visible would suffer scorch marks. No detriment to the growth of the plant, just looked unsightly. So we either shaded the containers mid day or covered the plastic container with black plastic cut from waste bin bags. Today we use plastic plant pots that have been discarded by garden centres and nursery growers as these are free and, of course, made for the job.
Just another form of recycling in action!
I am wondering what would be the best material to cover transparent bottles for plant growth :
a. black plastic cut from waste bin bags (see above)
b. white plastic (or paint) to keep the roots cooler ?
But after all, maybe we do not need to cover them !
Recycling used plastic flower pots from a nursery seems a good idea too, particularly to grow young trees. Once tall enough, the pot can be cut vertically in two halves (in order not to damage the rootball, like it happens regularly with the classical black plastic grow bags used in nurseries). I suggest to put the two halves of the plastic pot at the bottom of the plant hole at the moment of planting the young tree. An easy way of getting rid of that plastic.