OK to use fallen branch in garden without treatment?

Question

Recently a large branch fell off of one of our trees (a gum tree, ie hard wood). The branch is about thigh thick and parts of it would make a good garden-bed liner or similar as it is quite straight and uniformly thick. However, as it came fresh off the tree, it's obviously completely untreated.

I wonder if it is a good idea to use the branch in the garden as it is, or if this is a pest risk, especially regarding white ants (termites). If it needs to be treated can it easily be done / is it worth the effort or should I just get rid of it?

Answer 1

If you mean using it as part of a planter, then it will rot just as Doresoom has explained. Even if you treat it, the wood hasn't been properly dried which will cause other problems.

If you're just using it as a divider on the ground I wouldn't worry about it rotting. The rot will just supply the soil with nutrients. Since it's untreated, it's also safe for gardens that are grown for human consumption, as treated lumber harbors harmful chemicals.

I don't believe it will cause termites problems as long as it's not against any buildings. It's also a good idea to make sure the garden is not too close to your house, as the moisture from waterings can attract pests and encourage rot.

Answer 2

In general, one thing you might try is to avoid ground contact, possibly raise the untreated wood off the ground and use treated wood for the lower parts and line the parts of the wood in contact with soil some kind of plastic or other liner (beware of anything leaching into the ground). You can also use paint on timber treatments and timber waterproofing (gain beware of leaching) to increase the life a bit. Even then you probably shouldn't expect it to last for ever. Or you could just allow it rot and then replace it (since you got it for free anyway).

However, the particular type of hardwood you have might be particularly unsuited for outdoor work. So I would try to identify exactly what type of tree it is and do some research on the properties of that kind of wood.

If you can't use it and you have access to a wood chipper you could instead chip it and try to compost it.

I don't know what the implications are are far as pests living in the wood, mould fungus etc.