Although cauliflower belongs t0 the Brassicaceae family, small amounts will cause no harm to your pet tortoise.
The problem is when you feed too many, which may interfere with thyroid activity and lead to kidney and liver damage.
Can Hermann Tortoises eat Cauliflower Plant?
So, Can a herman tort eat cauliflower? as you can see, it is not toxic, but should be fed in small amounts, moderately.
ALSO SEE: Can Hermann Tortoises eat Carrots?
Can Hermann Tortoises eat Cauliflower Leaves?
In small amounts, the leaves of cauliflower would be ok to eat. If you feed too much, you risk negatively affecting your pet tortoise calcium intake.
With the lack of weeds at the mo you can resort to feeding the torts crispy floretti salad, watercress and romaine lettuce. I also feed mine watercress. There are lots of weeds they eat too