Friends are still bringing me last years teasels but unfortunately not many of them are viable. What seems to happen is that the spiky bits on the teasel break off and the head of the teasel becomes smooth. The barbs on the stem are eroded and the stem also becomes smooth and bleached in colour. The teasel heads often become radically altered....see below.

The new teasels are just starting to get going. 

Here's hoping there is an early bumper crop in my locality.