I guess it is a soil problem, dig a hole near the dying tree to see what its the problem. Might be clay underneath causing water problems. Had similar problem and lost mandarin, white rose, red rose because of this. Now after I modified the soil I have a healthy mulberry growing.

Logee's has a pretty good care sheet for the miracle fruit.
Click the "Synsepalum Plant Care" in the Logee link.

DM

Here is a link that might be useful: Logee Miracle fruit page

I've read it before, but none of them covers what the problem is for this. Both trees are under the same conditions, but this one has ALL it's leaves behaving desiccated even though its watered, and I think the red parts are a part of the problem. It almost seems fungal or virus like

I know nothing about miracle fruit...but if I had to guess the problem is your soil...Peat Moss and Topsoil are both very water retentive, I think your plant might be suffering from root rot? I would carefully inspect the roots and if you can change the potting mix to something that drains quickly and doesn't hold too much water...do a search on this forum for the 5-1-1 mix...Pine bark fines, perlite and peat...Good luck!!

I keep mine in 1:1 perlite:peat which is the standard medium for miracle fruit. Very fast draining and not a lot of water retention. I tend to agree with puglvr.

As far as I'm aware, miracle fruit are all grown from seed and are therefore not clones of one another. Different behavior in similar growth conditions can happen. Also if you potted them up into a larger container and kept the original rootball intact, one may have a tighter original rootball or have trapped some poor media in the center. This can cause rot.

You may want to try taking the sick plant out of its pot, removing all the soil, and replanting. They are sensitive to too much fertilizer, so maybe cut out the fert until the plant perks up. Dry leaves is often a sign of too much water or too many solutes in the water...

Now if I could only get mine to fruit!

Thanks for the replies!
I doubt it's root rot because I water once a week, and sometimes the soil on the surface is so dry it retracts from the side of the pot. However, it never gets too dry and remained healthy until last month when the red started to set in. I've had other miracle berry plants set red leaves due to chill, but the whole leaf turned red at once, not like this. Leaves are dropping like crazy now if I just barely shake it.

It's partly rootbound! Thanks for the suggestions. Only half the side grew extensive roots while the other side didn't grow much. weird it took this long to have problems. even fruited and stuff