In fact it was the largest of the several sticks I tried that has rooted, so that tends to confirm that theory. It was probably about 10 inches long, and originally had a few side twigs though I trimmed all but one of those off. I had chosen twigs with nice terminal buds, but given it has leafed from low down and the terminal bits all died, I'll forget that theory if I try again. This is the first time I tried it indoors, the books talk about doing it outdoors, but my outdoor attempts, both pots and in trenches (as the book suggested) with varying sized prunings all failed.

There is talk of "truncheon" cuttings for mulberries, but I read that this doesn't mean something literally truncheon thick, just perhaps a bit bigger than for most other things.

In China and India, silkworms are mostly fed on Broussonetia papyrifera, the paper mulberry, though I believe also white mulberry as someone said. Paper mulberry is a bit tender for Britain, but it has become an invasive weed in climates like Pakistan.

I already have a red mulberry tree of some 12 years in the ground, and I now have to prune it most years to ensure the fruit remains in reach, even though I pick it with a ladder. I don't have space for another. But I thought it would be good to use the prunings to try and grow some cuttings, either for friends/relatives who wanted one, since they are expensive, or even just to guerilla plant in some hedgerow of a disused field.