Portulacaria afra - deadwood & pot boundedness

[PeterD]

Hi,

I've recently bought a Portulacaria Afra from a nursery store. I am a little concerned about 2 things and I would appreciate your help/advice on them:

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1st question
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The nebari was heavily overgrown with moss due to just being in a greenhouse. So at the nursery, they told me to spray a little water and scratch the moss off with a toothbrush, which I did.
Then I immediately noticed, that the moss did some destruction in the tree. In the 2nd picture, I highlighted 2 areas with red:

- In the upper one, you can see that there is a hole in the trunk, like the root there came off some milimeters from its initial place. Good thing is that the big root itself seems alive and fine to the touch, except for the part around the hole, which feels like hollowed/dry rotted/deadwood (this might not be the proper word to use, but I hope it is understandable).
- In case of the lower red circle, if you gently scratch that part with your nails, it also feels hollowed/dry rotted/ like you could peel it off / deadwood and touching it gives off a different sound than touching other parts of the tree.

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2nd question
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The tree is fully pot bound, with the roots coming out of the drainage holes. Furthermore, even after watering, the soil surface feels like a solid thing to the touch (they told me at the nursery to water by submerging about 3/4 of the pot for 20 mins, so it slowly get soaked fully from the bottom).

Now the question is that today, I noticed some web-like white stuff on the soil surface and I can't decide if this is (3rd & 4th pictures, sorry if it can't be seen well, I didn't want to wait until it gets worse)
- unharmful mycorrhiza
- or some harmful blight/mildew/other harmful fungi appearing because the soil dries up too slowly & it is so compact that air does not really flow into it.


What are your thoughts & suggestions?

Thanks,
Peter

 

[PeaceLoveBonsai]

Cool tree!

I don’t think I would be concerned about the white powdery stuff. You mentioned there was moss on the tree, correct? If this was growing under that moss, it will most like die now that it has been exposed.

I would consider a re-pot at the appropriate time. Into something a bit larger.

Not sure on the dead parts. My guess is you will want to dig in and clean that out. Rot could bring disease. But don’t take word for it. Maybe some of our friends from down under can chime in, but deadwood is not something I see in mature p. Afras. (But haven’t seen a lot, so their you go!)

What zone are you in? Will this live outside or inside or combination of both?

 

[Wires_Guy_wires]

To my understanding, these kind of plants store water in their roots. So when those die, they don't have the structure that can be used for deadwood. When dead, they look like dried carrots, because basically that's what these roots are.
I know those kind of dead roots can be a source of rot and a nice home for gnat larvae. So if you're sure it's dead, I suggest you remove it just to be safe.

 

[Velodog2]

The plant looks quite healthy. If there are dead places on the trunk the bark will come off, as it is doing already, and new bark will form underneath. The thing to remember is that this is not a tree but a fleshy plant without real wood or bark in the strictest sense of the word. There is no such thing as deadwood. Dead areas will shrivel and rot away. What I called bark earlier is really like a thin skin.

Regardless, in my opinion they can make fine bonsai and are very receptive to most training procedures. They don’t mind being rootbound or even quite wet. If it is rootbound then watering as they suggested is a good idea as dry areas in the rootball will cause leaves to wither.

Being rootbound will slow growth but when you repot and root prune it remember to treat it like a portulacaria cutting. Put it into dry soil mix and don’t water until the leaves begin to wrinkle. Otherwise the cut roots will rot. Have fun!

 

[PeterD]

The plant looks quite healthy. If there are dead places on the trunk the bark will come off, as it is doing already, and new bark will form underneath. The thing to remember is that this is not a tree but a fleshy plant without real wood or bark in the strictest sense of the word. There is no such thing as deadwood. Dead areas will shrivel and rot away. What I called bark earlier is really like a thin skin.

Regardless, in my opinion they can make fine bonsai and are very receptive to most training procedures. They don’t mind being rootbound or even quite wet. If it is rootbound then watering as they suggested is a good idea as dry areas in the rootball will cause leaves to wither.

Being rootbound will slow growth but when you repot and root prune it remember to treat it like a portulacaria cutting. Put it into dry soil mix and don’t water until the leaves begin to wrinkle. Otherwise the cut roots will rot. Have fun!

Thank you for the detailed explanation. My only remaining question is, what is better for the tree, and for its aesthetics in the long run: leaving the dead "bark"/skin on, and let it naturally come off, or removing it? Can any of the options damage the tree and the new bark underneath?

 

[PeterD]

Cool tree!

I don’t think I would be concerned about the white powdery stuff. You mentioned there was moss on the tree, correct? If this was growing under that moss, it will most like die now that it has been exposed.

I would consider a re-pot at the appropriate time. Into something a bit larger.

Not sure on the dead parts. My guess is you will want to dig in and clean that out. Rot could bring disease. But don’t take word for it. Maybe some of our friends from down under can chime in, but deadwood is not something I see in mature p. Afras. (But haven’t seen a lot, so their you go!)

What zone are you in? Will this live outside or inside or combination of both?

Thanks for the advice. I will repot the tree when it shows signs of focusing the energy to the foliage = the leaf growth rate starts to increase (not saying 'starts' as it doesn't really have dormancy), somewhere in March. I hope I am not wrong with this.

I live in Hungary. We have winters around 0 Celsius here and usually a lot of rain in the summer. So the plan is to place it outdoors mainly in the summer. And protecting it somehow from overwatering by rainfall.

 

[PeterD]

To my understanding, these kind of plants store water in their roots. So when those die, they don't have the structure that can be used for deadwood. When dead, they look like dried carrots, because basically that's what these roots are.
I know those kind of dead roots can be a source of rot and a nice home for gnat larvae. So if you're sure it's dead, I suggest you remove it just to be safe.

Thanks. Oh I hate those fungus gnats. Still have some even though I placed those yellow sticky traps and repotted most of my trees to a grainy soil mixture of 80%inorganics, 20% bark. Probably repotting the remaining 3 will solve it I hope.

 

[Wires_Guy_wires]

Gnats thrive off of fungi and wet soils.
When they become a problem, it's usually because you've been watering too much.
I combat them in 2 ways:
1. Place all the pots in sand. Regular builder sand or whatever, as long as it's dry. This covers the bottom pot holes, so egg laying can only be done up top.
2. Don't water the plants for as long as possible, and after that a minimal amount for a few days The larvae dry out in a matter of minutes when there's no moisture. This is risky, so I do it only in the weekends. Allowing the soil to dry completely also kills the eggs.

They're usually gone after one single treatment like that.

 

[Velodog2]

Really it doesn’t matter how you treat the damaged areas. Since the bark/skin is so thin it repairs itself quickly. Slice away underlying soft tissue until the contours are smooth and the exposed areas will skin over quickly.

I know conventional wisdom says these plants prefer to be dry, almost as if they were cactus, but that’s not my experience. Again, with the exception of post-root pruning, I keep mine quite wet. They grow well in gravel sand that I water every day. Typically it is recommended to transplant when they are growing strongest, such as the height of summer.

 

[Carol 83]

Really it doesn’t matter how you treat the damaged areas. Since the bark/skin is so thin it repairs itself quickly. Slice away underlying soft tissue until the contours are smooth and the exposed areas will skin over quickly.

I know conventional wisdom says these plants prefer to be dry, almost as if they were cactus, but that’s not my experience. Again, with the exception of post-root pruning, I keep mine quite wet. They grow well in gravel sand that I water every day. Typically it is recommended to transplant when they are growing strongest, such as the height of summer.

I tend to agree with you about the watering. P afra seem to went more water than a regular jade. Mine are in cactus/succulent soil, but need to be watered twice a week. But they are in very small pots, also.

 

[Velodog2]

Lol I don’t know what the heck I meant by “gravel sand”, but probably meant to say granite sand, ie fine chicken grit.

 

[just.wing.it]

Really it doesn’t matter how you treat the damaged areas. Since the bark/skin is so thin it repairs itself quickly. Slice away underlying soft tissue until the contours are smooth and the exposed areas will skin over quickly.

I know conventional wisdom says these plants prefer to be dry, almost as if they were cactus, but that’s not my experience. Again, with the exception of post-root pruning, I keep mine quite wet. They grow well in gravel sand that I water every day. Typically it is recommended to transplant when they are growing strongest, such as the height of summer.

Even after repotting, I've given mine a thorough watering, just like any other tree....never had issues.
Conversely, I've also been known to let mine dry out between waterings.
As I learned it....somewhere along the line....the Portulacaria Afra will only grow roots if the tree is searching for water, and in those times, it draws water from its "storage reserves" in the foliage (and the rest of the tree).....and if they stay moist, they'll grow up top quite leggy, but not grow the roots.

 

[Bonsai Nut]

Even after repotting, I've given mine a thorough watering, just like any other tree....never had issues.
Conversely, I've also been known to let mine dry out between waterings.
As I learned it....somewhere along the line....the Portulacaria Afra will only grow roots if the tree is searching for water, and in those times, it draws water from its "storage reserves" in the foliage (and the rest of the tree).....and if they stay moist, they'll grow up top quite leggy, but not grow the roots.

I think it is correct to say that as long as they have free-draining soil, they can almost take as much water as you are willing to give them. I have two medium-sized ones that grow in large pond baskets in 100% pumice. They get watered twice a day (in the summer). I have yet to see any roots protruding from the baskets, and yet I consider them more water-hungry than my pines and junipers.

The issue with root rot isn't water - it's soil.

 

[Velodog2]

I think it is correct to say that as long as they have free-draining soil, they can almost take as much water as you are willing to give them. I have two medium-sized ones that grow in large pond baskets in 100% pumice. They get watered twice a day (in the summer). I have yet to see any roots protruding from the baskets, and yet I consider them more water-hungry than my pines and junipers.

The issue with root rot isn't water - it's soil.

Well, not to belabor the point but actually the grit I put mine in is surprisingly poor at draining due I think to the particle size. I’ve pulled plants out of pots where the bottom of the root pad, which were solid with roots, were sopping wet. They like it it seems, although I’m not saying freer draining soil wouldn’t be as good or better. This just works for me. The only problem I’ve had is after repotting. The wounds rot, or something.

 

[Todaru123]

I wouldn’t be overly concerned about dead spots in the tree. It looks like a spot where a branch has come off. I get similar outcomes when removing a large branch close to main trunk. I wait until the cut has shrivelled and then pull it off. It leaves a hollow spot which then will callous over and make what I think a pretty cool feature of the tree. I’ve attached some photos below as an example. Can’t really tell from photos but this stump is around 30cm (it’s big) and the cavity goes in around one third of the way into the trunk. It doesn’t hurt the tree which Continues to grow strongly. I also water frequently in summer sometimes twice a day when it gets hot (I’m in Melbourne Australia and we get some really hot days in summer!). But I do use a very porous mix.