You can patch but most of the time it won't match. I have some planters that I broke a corner and I just plant things that overflow the broken area.

I agree with Billie, take what you have and plant it.
If the hypertufa was still damp - freshly made, you may be able to repair the next day, but once it has cured it would not be as strong, and likely to just break off eventually

I had a round bowl where one side broke when I was moving it when it was still curing and I just planted and it turned out ok -

Mike

Here is a link that might be useful: hypertufa

hypertufa to hypertufa makes for a weak bond.

I don't know if this will work for your situation but what I have done once is 50 50 mix of grit sand and cement mixed with sbr ideally if not pva. soak the hypertufa you are sticking this mix to thoroughly as this will help make the bond stronger. I let the cement sand mix be slightly more on the watery side in consistency. patch it up and keep a polythene bag over the area you are repairing..the slower it cures the stronger it will be. Once that dried a few days later I added my usual hypertufa mix on top of the mix as to conceal the differences in textures Making sure to add sbr to my hypertufa and wet the repaired area before applying...then covering it again with a bag. It will look odd initially but as time goes by it blends it a lot more. It will not be perfectly blended but it will be hardly noticeable.

This post was edited by themes on Tue, May 28, 13 at 21:31