I've been into tall ripe barley in July, and although the deceleration was rapid, the tailwheel stayed on the ground and the aircraft was undamaged.
However, I know of one excursion into oil-seed rape adjacent to a runway where the undercarriage stopped and the rest of the aircraft kept going.
Glider pilots are more savvy on this subject. I've seen somewhere a presentation on recognizing suitable fields at different times of year, so you can pick the right field before you're comitted to it.