In an earlier post on growing Xanthorrhoea, a comment was made about using milk cartons as a cheap deep pot that will accommodate the root systems of Australian native plants. As a result of that comment, ‘Roughbarked’ sent some very useful ideas on how to actually use the milk cartons as planters and as tree guards. I have been saving milk cartons for a while as I am about to replace a couple of hundred plants, and we have a family of hares and some rabbits. (If I had my way they would all be in the stew pot!) The destructive pests wil eat plants off below the last set of leaves leaving no opportunity for re-shooting, and resulting in the loss of the plants. Commercial tree guards are available, but of course the extra funds spent on these could go on buying plants.
This is the very useful comment made by ‘Roughbarked’.
Milk cartons as pots and tree guards.
I use a knife and stab the cartoon on each of the four faces once, in or near each corner. If you use a knife long enough you can stab right through two sides at once, flip the carton stab it again the same way and the job is done. I also cut the folded top part off so that all cartons have a neat and equal size. The stabbing leaves only slits so the water can drain but not drain too rapidly. Yes, the bottom of the carton will deteriorate and I have often just slipped the old carton off and slid the lot into a new one.
The benefits of milk cartons as a pot for natives are the long straight sides and the corners. The roots will hit the corners and follow the water down to the slits I cut. This creates a healthy root system that cannot become pot bound.
When planting out from milk cartons, I will point out that it is the only useable pot for natives, that does not have to be upended. I just tear or cut the bottom off, grasp the carton by the top and drop it downwards. The plant roots and mix all stay together and slide out into the hole you have dug. The milk carton slides upwards. Stop it just before it slides all the way off. Water and backfill the hole leaving the milk carton as a tree guard. Done with skill, this does not require stakes to hold the carton erect. The carton will remain for up to two years as a tree guard that is biodegradable and will not cause the trees stress by becoming a tourniquet, as some plastic tree guards do.