When to start planting trees + will willow branches grow furter even when covered

Hey!

I've 2 questions coming up.
I'm wondering if the small trees can be planted direct from the beginning of the Hugelkultur?
or do you have to wait a bit for the dirt to become more solid so the roots will hold better and how do you help the trees stands up against the wind.

I've read about using willow wood. My experiance with willow (as we like to prune them in The Netherlands) is when you put a cutted branch back in the grond, it easely becomes a tree itself.
Is that not a problem when you put willow branches or just some willow wood in a Hugelbed and cover it with soil? Won't there grow trees out of the (smaller)beds then when the layer of soil isn't large enough?

Note: Willow is a very nice tree to have for the branches as a small tooth treat for your animals (horses, rabbits, dogs) or to make baskets or natural fences with it. Or for fencing a riverbank.
Having a pruned willow growing on your land is like receiving a very nice gift, so why not using them?

Thanks for your replies!
(Sorry for bad English)

Generally speaking I don't think it is the best idea to plant any trees in a hugelkultur. I believe the best location for planting a tree in this system would be at the base of the hugel bed or just a few inches (cm) up the slope where the mound is solid dirt. There is too much potential for settling over time with the wood core bed as it decomposes. As far as support against the wind, I would do my plantings on the leeward side of the prevailing wind direction (i.e. use the hugel berm as a wind block).

If you use fresh willow wood in the hugelkultur it is very likely to resprout and grow a new tree. If you want to use it make sure it is thoroughly dried out and dead. Otherwise just plan on having new willows popping up. Not necessarily a bad thing!