I have been collecting empty gray cardboard toilet rolls in a large bag in the toilet, with the project to use them for planting seeds. Apart from the recycling aspect, the advantage is that carton toilet rolls are organic and degradable. This implies that you do not have to pull the seedling out of it before planting. You can plant it in your garden as it is, without disturbing the roots. Also, cardboard absorbs water so that the soil remains humid. I have read elsewhere on the web that the quality of rolls differ, and some unfold quickly when wet. Experiment before planting 50 seeds 😉
How to proceed? With a scissor I made some lengthwise incisions until a third or quarter of the roll, and fold the strips inwards. Now you have a quite unstable pot – don’t worry, after putting humid soil it will soften and form a bottom. I place several rolls tightly (prevent them from rolling over) in a plastic recipient without holes, for example a purchased strawberry or mushroom box. I water the box when needed and the rolls will absorb it bottom-up.
I use toilet rolls especially for the somewhat longer root plants. Peas are a good candidate. Also peas do not like to have their roots disturbed, I read, so maybe this does the trick? I also transplanted chard in rolls. When it is time to transplant I will unfold the bottom and the roots are free to continue. The question is how these rolls keep over time. My pea seedlings are now for three weeks in toilet rolls and the rolls look sturdy enough.
I had saved up a cupboard full of egg cardboard in different sizes, 6, 12 and 24. I thought these would make perfect little holes for small plants, which I can just break off cell by cell to plant them. The cardboard would decompose and the plants continue growing happily. Prefer for that reason brown and grey cardboard which have no ink or bleach. I ripped of the lid, which I put under the rest as a platter, put in some moist earth, and they were ready for use. I used them for salad, mâche, and tomatoes – because these come in large quantities and wanted to give them all place under the grow lamps.
The salad and mâche grow correct in egg-boxes. I can water the lid-platter under the cells and the cardboard would absorb the liquid moistening earth when needed. However, cardboard tend to dry out much quicker then plastic recipients (good for those seedlings who hate wet feet, I suppose), but that could be remedied somewhat. More difficult was the splitting of the cells, because the cardboard became dryer at the rims which made tearing them apart difficult. Splitting the cells is easier when you drain them a bit in water just before splitting to soften the cardboard. In some cases the roots came entwined with the cardboard and therefor I broke some roots when splitting, but most of them were nicely separable in cells. I planned just to opened the bottom of the cell a little bit to give them a way out, but it turned out easier to rip the sides, get it out and plant it without the card board. If I try this again, I will leave the seedlings somewhat longer than 2-4 leaves, in these cells, so that they grow stronger and bigger to handle.
Egg boxes however are a bad idea for tomatoes: they germinated perfectly and then stagnated for weeks to make more leaves. The cells as too small. Roots were nicely all over, but no real leaves and therefor I was resilient to transplant them in a different pot. Eventually I transplanted the tomatoes plants after 3 weeks with only 2 or 3 fragile leaves. Tomato plants are not apt for growing in egg boxes – put them in something larger. I hope my plants will recover quickly because in Finland the season is over before it has started.
Please share below your garden potting recycling ideas and experience.