It is extremely easy to transform (recycle) a plastic bottle into a mini-greenhouse.
Here are Tine DAU’s photos showing how simple and cheap that is:
On the foreground, a seedling is growing in a small bottle of which the bottleneck has been cut off. Two opposite drainage holes at 2-3 cm above the bottom of that bottle avoid that too much water could stand in the base. It is partly filled with an organic potting mix (local dirt with some manure).
The taller bottles (1,5 liter) in the background have been cut transversely (cross) for almost 95 % at 10-12 cm (4-5 inches) above the bottom, leaving the upper part of the bottle attached at the bottom part over a length of 2-3 cm. Thus, the upper part can be bent over to open the bottle and fill the bottom part with potting mix, in which the seedling can be planted. Do not forget to perforate the bottom part with two opposite holes for drainage.
Finally, the upper part is put back in its original position (as if the bottle is still intact). Thus, the seedling is growing inside the bottle, acting as a mini-greenhouse.
One can also control the humidity inside the bottle by :
(1) leaving the cap (lid) on top, which creates condensation of the evaporated or transpired water on the bottle wall;
(2) taking the cap off to let water escape through the bottleneck.
This can be interesting for growing seedlings in the drylands or in drought-affected regions.
Grown to a maximum in the bottle mini-greenhouses, the seedlings can be transplanted into other containers (pots, buckets, sacks, bags, barrels, drums, …) or can be planted directly in the soil.
ADVANTAGES OF THIS TECHNIQUE :
Saving water (almost no water loss)
Higher temperature inside the bottle
Sufficient light inside the bottle
Less variation in temperature around the seedling
Protection against insects
Better and faster seedling growth