Thursday, January 29, 2009

Honey Locust, Gleditsia triacanthos: This short blog is by way of a thank you to all those who posted comments to my blog of 24th November on black and honey locust trees. There are many interesting comments, so do have a read if these trees interest you.

Permaculture is site, situation and person specific, so what’s good for someone might be a problem for somebody else. Kate, who lives in western Washington State, USA, told us that black locust trees are extremely invasive and the number one weed in her garden. On the other hand, she does admit some benefits: “They do however fix nitrogen and I am grateful to them for the wonderful soil they have left behind. They might also make a nice tree for coppicing, as the stumps sprout prolifically and the wood is very strong, rot resistant and makes great firewood.” And on the toxicity, she feeds “the leaves from the sprouts to my chickens and they love them. I haven't had any ill effects in two years of doing this, so the leaves at least are not toxic to chickens.”

Hargi, who lives in Hungary, is a fan: “here in Hungary the best honey is from black locust. Its wood is used as pole, tool handles, stakes etc, because it is relatively rot resistant, and for firewood as well.” And regarding toxicity, she told us, “the leaves of black locust tree are not toxic to rabbits (first-hand experience). The flowers can be eaten without problem, even for humans.” She also said that Honey locust is used there as a hedging plant.

A perfectly useful plant, can often be more successful in a new environment that it apparently is not adapted to. So while Japanese knotweed, gorse or black locust lives in equilibrium with other species in its homeland, it can become an invasive nuisance when it grows in another country, perhaps deliberately introduced as an ornamental. For this reason, one should be ready to question the advice in all-encompassing permaculture manuals. If the idea is that a particular shrub or tree fixes nitrogen, supplies mulch material and feeds animals, it would be better to try to identify a plant from your own country that has these properties, rather than just choose the species referred to in the book. You’re not ignoring the advice of permaculture sages, just adapting it.

We’ve already planted several black locusts on our own permaculture smallholding and have just been given a honey locust by our farming neighbours, Paul and Christiane. That’s been planted in our nascent chicken forage system, designed by our recent volunteer, David (more on that soon).

Photos from top: Honey locust tree, its seed pod, its thorns.


Anonymous said...

Black locust rarely germinates from seed, and usually only becomes locally 'invasive' when a landowner/homeowner tries to get rid of them in the wrong way. If a black locust is simply chopped down it will send shoots out from the stump and/or send out root suckers and it will be a heck of a job getting rid of them then. To effectively get rid of black locust is to girdle the tree (cutting a ring through the bark, cambium and sapwood, around the trunk and waiting for it to starve before cutting it all the way down. There are a lot of misconceptions and negative reactions about this extremely useful tree stemming from ineffective attempts to rid a property of them which lead to proliferation. With the right informed methods they can be easily controlled.

Stuart and Gabrielle said...

Thanks for posting a comment and advancing our knowledge a bit more!

Ryan said...

I am seeking out some permaculture suggestions on Japanese Knotwood.... Do you know of any books or sources that have ideas/suggestions for this dominant plant? Thank you!

Stuart and Gabrielle said...

Hi Ryan,

I've left a response on your own website.