Another view

Another view

{{!gwi}}

If it's planted in a pot and still indoors, probably tired from the attack to take up moisture and then root rot from that effect..Also too reverse that..

A weak plant from poor mixes and over or under watering are prone to mite attack and dead twig to branch die back..

I would fix the mix and happy the roots asap in lot's of outdoor light and warmth...

MIke....

Hi, were you able to resolve this issue? My dwarf lime tree's branches (it's in a container) have also been turning black. It's not sooty mold because it doesn't come off, and they're not drying out and dying--they're merely turning black. I'm trying to find out if this is symptomatic of a bigger problem, but can't seem to find any answers.

The tree itself is also suffering from overwatering and fungus, so we're dealing with that too, in case that might be causing the blackened branches.

I have a small CaraCara orange that was doing this, plus the leaves were turning pale green and dropping off. I had re-potted it in better draining soil, but it was still happening. I suspected the original potting mix it came in was the problem, as I only put new better draining soil around the older soil.

I pulled it out of the pot, removed the newer soil, and examined the old potting soil. Sure enough, the old soil was very heavy and smelled bad. The tree's root had a few nice white roots, but most were brown or tan and mushy. There was a rotten smell too. So I pretty much bare-rooted it, ie, gently pulled off the old soil.
I had to cut off all the brown mushy root, which was about half or more of the root system. I rinsed it clean with plain water then re-potted it in a 5-1-1 mix, set in bright shade outside and waited.

It was scary at first as the tree promptly dropped the rest of it's leaves until it was bare branches. Some of the green branches continued to turn black and I was worried I had pushed it past the brink and it was going to die.

I also watered it very, very little, after re-potting, as the soil dried slowly in the shade. I checked the soil moisture with a thin wooden dowel to make sure it was dry down almost to the bottom before I watered.(btw, by "dry" I don't mean dusty dry! I mean just barely moist, like a wrung out sponge that's drying but not hard yet, if that makes sense) Really only watered it twice in the whole time.
But then after about 4-5 weeks the turning black stopped, then about a week after that I saw tiny new little leaves starting to grow. Yay!

It took about another 3-4 weeks for them to grow out, and even though they're a little on the small side, they're all nice and dark green, firmly attached and healthy! It's even now starting to elongate new branch tips from some branches. I am slowly putting it into an hour or so more sun every few days and eventually it will be in almost full sun.

Imo, the blackening stems are a sign of distress roots, usually from heavy soggy soil. When soil stays wet too long it drives out the air in the mix. A healthy soil needs both air and moisture, and when it's only moisture, the roots literally drown and then start to rot.

I would investigate the condition of the roots if I were you. Slide it out of the pot and examine them. Healthy roots should be a light tan to white, and be firm. Rotten roots will be dark brown and mushy. If it's root rot you may need to re-pot like I did. Good luck!

This post was edited by BarbJP on Tue, Jul 29, 14 at 13:29

Hi BarbJP, thank you so much for your detailed response! I'll definitely give this a try; it kind of sounds like hitting the restart button on the tree but I'll be super thrilled if it works. Best of luck with your trees and gardening.

Hi Barb I am getting die back and branch blackening on my favorite chinotto sour orange!

It was totally fine, I just got 8 smallish oranges from it last month. I recently repotted into a 5-1-1 and it immediately defoliated which happened the last time I repotted so I wasn't worried, but now a ton of branches have blackened. I repotted 3 other trees of equal or less vigor into the same 5-1-1 and they responded positively immediately so it's not the mix. I also cleaned the root ball very well so is it just shock?

I cut the dead branches off trying to get ahead of the blackening. I will do the rest of what you suggested. Will it make it? I am terrified!

It is probably shock. I think the blackening is from damaged root tips. And that can happen from root rot or from mechanical damage, which is what happens when we re-pot.

It's unavoidable that some of the roots will be damaged when re-potting. But if your tree has lots of healthy roots, loosing a few won't usually set it back much.

Maybe your sour orange had fewer roots to start with than the others and so the damage was more noticed by the plant? I think you've done all you can do at this point. Maybe just observe, water sparingly but don't let it dry out, and hold off on fertilizer until it puts out new growth.

Sometimes it can take several weeks for some trees to recover from shock.

Thanks Barb much appreciated! Ok I will cross my fingers. Here is what it used to look like just a week ago minus the fruit, and minus some leaves that got a bit crispy during the transition outside. I had transitioned it outside and then repotted a week later so maybe that was too much for it. The other 3 trees took it fine but the chinotto is more delicate I think.

And here it is now

Scary right?

Being a smaller tree in a smaller pot it did have a smaller rootball so it is very possible it is in shock from me manually removing the old dirt from the roots. I'm pretty careful but I guess it is a traumatic procedure no matter what.

Yeah, that was a pretty tight pot. Hope it recovers, good luck.

Oh no Hobby! That tree was lovely! I hope it is just shock and will recover. Fingers crossed for you!!

Hobby...I am glad your other trees did ok. Now is not the optimum time to do a bare root on any tree held indoors for the winter. They are transitioning to outside and at this time trying to figure things out. until your trees start actively growing about Fathers Day, try not to do a bare root in the future.

Your tree was so beautiful. I hope it comes back soon for you)

Thanks guys I know, it's a disaster. How did things go downhill so fast?? I'm quite disappointed but trying to think positive. It did drop all its leaves last year after I potted it up then. The dieback is new though. I'm obviously still a newbie train wreck!

Here are the other 3 that I potted up at the same time, they are loving it I think. Within a day all 3 of these guys had their leaves at full attention after repotting and even some new growth already.

Calamondin, key lime and variegated lemon.

Thanks Mike that is exactly the kind of stuff I need to know. Of course it makes sense not to overstress them when they are still getting used to outside. Hindsight I guess. I think I was just worrying all winter knowing they were in a bad mix after hearing all the horror stories so I was super anxious to get it swapped out.

I have since repotted another 6!!! They seem to be fine though so I hope that trend continues. I have them back in my grow room getting used to the mix and will transition them back out on Monday I think.

I still have at least 5 I would like to do but I will take your advice and hold off. I will provide updates.

Yes, please keep us updated!

Hobby, is the key lime the tall one in the middle? I have a key lime that looks a lot like that one. Is it thornless? Mine is, but it's growth is sooooo much slower than the other key limes that are bushier and thorny...those are growing like weeks. I may start a post about that...need to take some pics.

Hi Laura yes it is in the middle and yes it is thornless too! I also find it very slow growing, actually it has barely grown at all since I got it a year ago. But as we know now apparently my mix was very poor so no wonder, but I did get 2 flowers this spring, the first ones! And it has started 3 new sprouts since repotting in 5-1-1 so I am happy.

Interesting about the prolific bushy types i'm curious too. That would be a good thread! Thanks a lot- now I want one of those types ;)