Eucalyptus trees are unsuitable for Hügelkultur

From your experience what tree timbers do you wish you avoided or found don't perform as well in a Hügelkultur system?
Here in Australia we mostly have gum (Eucalyptus trees) and unfortunately deciduous trees timber is hard to come by.
From what I've found Gum tree logs just don't get that same sponge thats so desirable for Hügelkultur.
So if you have them nearby dont make my first attempt mistake and avoid eucalyptus wood/branches and leaves as their allelopathic substance from the flammable oils they produce stunts plant growth, make soil hydrophobic and can take decades longer to break down. I've also found that because they are resistant to rot and timber so dense that they stay dry until termites eat them away.
Usually need about 6 months of aging for the allelopathic substance effect from eucalyptus material to wear off.

Makes great timber for counter tops, tables, chopping boards, benches and excellent firewood for many of the same reasons mentioned above.

Thanks for the tip. Eucalyptus also makes great mulch. Nature decides when it's ready to integrate with the soil.

Nathanael Szobody wrote:Thanks for the tip. Eucalyptus also makes great mulch. Nature decides when it's ready to integrate with the soil.

I find it makes a good mulch if you let it age for at least 6 months first. Let those compounds leach out first. Unless you want to take advantage of its natural retardation of other plants growthing underneath 🤔

I've heard it recommended as a good wood for growing mushrooms on.

I’m felling 22 mature eucalypts on my block as soon as I start clearing.

My plan in no particular order is
Stumps removed off site where out of the ground
Left in and turned into mushroom stumps otherwise
- Trunks milled for construction
- Heavy branches down to 125mm gifted to neighbour for firewood
- 125-75 dia cut to 1m and used as mushroom logs
- 75 down to 20 used for check terraces and backfilling à la hugelculture
- Tops - dried for biochar ie 50mm down to leaves

Oops, sorry I went off the topic at hand while I was waffling about my own situation. The hugelculture beds I’ve made last spring use eucalyptus and black wattle. I haven’t noticed any issues with it. Should I keep an eye out?

Ross, I have to ask, why buy a block with so many mature trees and then cut them down?

Eucalyptus brash would also be excellent material for making biochar with - you would need suitable equipment to do it safely in fire prone country