2 years ago I put in the ground ~ 100 cuttings of a prune job on a weeping willow tree.
My goal is to use them as a pioneering species to help suck up excessive ground moisture while providing carbon for the soil by means of chop & drop.
Eventually plan to replace most of them with fruit/nut trees, perhaps food forest.
Nearly everything made it perfectly fine and is taking off beautifully.
The average diameter is now ~ 2-3 inches. Some are ~ 1" diameter.
When would be an ideal time to start coppicing some of them?
Is there a diameter size I should be looking for? Age of tree matter, etc.. ?
In my (limited) experience, Willows tend to be very resilient. I've had newly rooted whips get run over and/or mowed down to the ground and still come back up. On the other hand, I've witnessed old, mature trees get broken at the base in windstorms, and the fallen trunk rooted where it fell while the original stump sent up new shoots.
I would think it would just depend on the health of the tree, and the purpose of the coppice. If I were using it for livestock fodder or mulch I'd be inclined to chop it earlier, while the growth is young & tender. If I was going to use it for posts or hugels I'd prefer it to be more mature/woody.
One more thought- I'd be cautious planting the willows where I someday want to put a different tree, just because they are so resilient. Once they're well established, one would likely need to remove the stump & root system to prevent new sprouts when it's time to plant the new tree. Additionally, I've read accounts of people planting fruit trees near an established willow root system and the fruit tree suffered and/or died due to the willow's excessive hunger & thirst taking up the moisture & nutrients.
In other words, if the end goal is for fruit tree or food forest establishment, then that should drive the willows' management, yes?
Your end goal is not to coppice willows for coppice sake, but to get the land in the best position for useful food crop. So if the soil is ready, plant your food forest and start chopping and dropping those willows!
With ~100 trees, you have plenty of leeway for flexibile trials or prototypes, too, should you wish to cull a large percentage of them.