If you start growing plants from seeds, you can re-use used toilet paper rolls to start your seeds growing. This article explains how to recycle toilet paper rolls and paper towel rolls to use in starting your plants from seed.
Toilet paper rolls and paper towel rolls, the cardboard tubes that are left over when the toilet paper or paper towels are used up, are a rigid tube that can be used as starter containers for your seeds and small plants.
To use them, start out by getting a flat tray container with an edge that extends up about a half an inch. I use a window box drip tray. This tray will be used to hold the tubes as your plants grow. Now take a toilet paper tube and cut it into three equal height tubes and arrange the cut tubes on the bottom of the tray. If you use a paper towel tube, cut it into six equal size tubes. Fill each of the toilet paper tubes about half way with clean quality garden soil from a garden center or hardware store. Do not use ordinary dirt from the ground since it has all kinds of vegetation already living in it (weeds, grass, etc.) and you will not know what is your seeds and what is weeds. Place your seeds on the top of the soil and then cover the seeds to the top of the tube.
The beauty of the cardboard tubes is that they will absorb and hold water for a longer period of time keeping the seeds or small plants wetter for a longer period of time. In order to water the plants, pour the water into the bottom of the tray and not on top of the tubes. Pouring the water on top of the tubes will bore holes in the dirt and may displace the seeds. By pouring the water into the tray, the water will fill the bottom of the tray and the tubes and dirt will suck the water up through capilary action keeping the seeds or plants moist.
Starting your seeds in this manner will allow you to bring them inside if cold weather or frost is suspected extending your growing season by starting earlier. Once your seeds have sprouted and grown a couple of inches, you can take the whole cardboard tube and plant it in the garden or other final destination. Any roots that the plant grows will extend below the bottom of the tube and into the ground without problems. The tube can also easily be removed if desired before transplanting.
The picture shows the toilet paper rolls in the window box drip tray with a pea plant growing from seed.