I know Pyracanthas doesn't like root pruning very much. I bought a Pyracantha 'Mohave' and it was big time pot bound. I had to cut the bottom 1/3 to make it fit in the pot. Will it survive the root pruning?

Yes. I have trimmed 90+% off of mine, and it did not flinch.

I am not sure what you mean by cutting 1/3 to fit the pot. Did it not come with a pot? And if you just wanted a nicer pot, why not wait till spring, and do a proper repot?

It was in a plastic pot and I cut 1/3(height of the roots) at the bottom. The high of the roots was about 6inch deep. It is currently spring here in South Africa

What's done is done, just wait and see, I must agree with LB, to late now. Again, there's a good chance for it to live, just don't expect a lot of growth next year.

Gekkie wrote: It was in a plastic pot and I cut 1/3(height of the roots) at the bottom. The high of the roots was about 6inch deep. It is currently spring here in South Africa

Ok, makes sense. i would however have done a full repot instead.

The I bought was to small and I've done a proper repot in a bigger pot. At least both the Mohave's I got is healthy.

OK, I misunderstood then i thought you just cut the bottom off, and potted that up. But you did do proper rootwork then. Sorrter which roots to keep, laying them out properly etc?

At first I did just cut the bottom off and put it in a new pot. Because the new pot was even smaller than the plastic pot I bought 2 new training pots for the Mohave's. I felt I was neglecting the repot so I've done a proper repot, root sorting and everything else like I was suppose to do the first time.