Branch with roots growing from section that was under gravel. © Eugene Brennan
Plants reproduce using multiple different methods. You probably know about seeds, but other ways they can reproduce naturally include sending out rhizomes (horizontal underground roots that send shoots to the surface) and above or below ground stems called stolons (AKA runners in the case of strawberries). Plants can be reproduced artificially by taking leaf or stem cuttings, by division (splitting a plant down the middle into two or more pieces using a spade or knife), budding (used for propagating roses) and grafting (used for fruit trees and other plants that don't readily grow from stem cuttings). Another method that occurs naturally and can be done manually by gardeners is layering. This involves laying a stem on the ground and covering it with soil or in the case of aerial branches, surrounding the branch with some compost and covering with a plastic bag or film. In both cases, roots eventually grow from the branch at the point where it makes contact with the moist soil or compost. Then the branch or stem can be cut off and planted and will grow independently of its parent (although technically only seeds have parents. Plants reproduced by other methods are clones ). The photos below show layering that occurred naturally on a sycamore tree down my garden. Whenever I'm doing construction I have to get rid of all the soil. I've probably disposed of tens of tonnes of stuff over the years, building up the ground or tipping it into the hedges. I had piled up some clay around the sycamore tree and inadvertently buried one of the still attached branches that was close to the ground. I had to cut the branch to get a wheelbarrow under the tree this morning and when I pulled the submerged section out of the soil, I discovered roots had sprung from the side of it. I've also seen this happening around the trunks of trees, when gravel was piled up against them.
Roots growing from end of branch. © Eugene Brennan
