Hello Rudi,
The last few years, I have been germinating mulberry
trees from seeds, here in Northern Greece.
I collect seeds from
wild mulberry trees, let them dry, separate the seeds, and then simply place them in a flower pot with soil... and cover them with a thin layer of soil, and
water them...make sure they do not dry out. You may only get 10 – 20 % germination rate, but seeds are cheap and plentiful around here.
Once the trees grow, you can graft them, and from each tree, you can have 3 to 4 varieties of mulberries.
Its a great tree – one of my favorites.
Trees grown from seed, are a strong and healthy.
Good Luck
Kostas