Well, the problem is they don't like being moved or disturbed when in active growth, especially beets. However, I've been successful and you should give it a go. Also, go ahead and start up some new seeds anyway.

Transplant them carefully & disturbing the roots a little as possible.

That's great news, I hadn't actually planned to move them; they are in the beds they were planted in. I was only thinking of mulching around them with compost if there was a chance of them continuing to grow. Many thanks.

There shouldn't be any problem with the kale. Root development on the beetroot may be a bit iffy, though. I would try putting some washed seaweed with the compost, and be ready to have beet leaves, instead of roots.

Haha! Thanks for the tips.

i.e. the beets I've been successful in transplanting were teeny tiny little seed sprouts maybe a half inch high. To transplant a mature beet - sauteed leaves in butter or olive oil with chopped red onion and a dash of hot sauce for the well seasoned palette. Plant some new seeds.

Mmmm...sounds good, Bathgate! :)