I've had a mild interest in Tecoma capensis (used to be Tecomaria capensis), cape honeysuckle. But today my generous friend Nigel asked me if I wanted any of his, showing me a self-layered stem. I was impressed at how well it had rooted, and I eagerly said 'yes please'. I thought it definitely worth trying in my slope stabilization trials. You can see from the photo that, as well as rooting from each node, it is putting-up whippy shoots from each node. I intend to peg those shoots to the soil in the hope that I can build a carpet of layered stems, and consequently a dense network of roots.
With a bit of luck, I will also be able to gradually bury the layered stems, then layer subsequent stems a bit higher up in the soil strata and at an angle to the earlier ones. That way, I'll be developing the network of wood and roots in three dimensions - which should help retain the soil and reduce gulleying caused by storm rains. To be able to retain loose soil on a steep slope is my primary aim, but to be able to accrete soil would be a bonus.
I'll have to see how the plant copes with having so many roots in a limited volume of soil. But the species is normally quite vigorous; if I can redistribute that enthusiasm into producing more but shorter trunks, that would be fine.
Update: added three more photos, showing more of the plants (including some Viola odorata also planted to help hold the soil), and to give an idea of the slope they are planted on
