Is my serissa ok?

[Carmen]

I've had this serissa for 3 years indoors. I got it in a 2" pot and put it in Pro-mix potting soil as advised by the nursery owner. I repotted it for the first time in February in a standard bonsai mix. A few days later most of the leaves turned brown and shriveled (not crispy) which I think was caused by putting it back in direct sun after repotting. I kept it out of direct sun for several weeks and there was lots of new growth.

Then I made another mistake by trimming branches without new growth that I thought were dead. Most leaves turned brown again. It's finally starting to grow back green again, but I've noticed tiny brown spots on a couple leaves that seem to be growing until the whole leaf is dead. I also noticed the base of the trunk is black (from when it was in potting soil) but started having white fuzzy mold (?) on it since it's been repotted. The serissa is now on a south facing window sill with air circulation and the spots seem to be mostly gone but the bottom of the truck is still black/white.

I live in upstate NY in an apartment so I cannot put it outside. Please help!!

 

[TimIAm]

It's hard to tell exactly from photos, but often dark colour at the base of the trunk can be a sign of a trunk which has been kept constantly or frequently wet.

Watering is quite tricky because there are quite a few variables. If you are keeping a tree indoors all the time, the amount of water it requires is going to be different from a tree which is outside in the wind and sun which are going to dry it out much faster. With bonsai, we don't want the soil to stay constantly wet, that's why bonsai soil mixes have larger particles than 'potting mix' so that the roots don't stay constantly damp. We want the mix to retain some moisture, but get to the point where it *needs* to be watered again at some point, usually within a day.

I'm not saying this is 100% a watering issue, just a possibility. The question I get when looking at the pictures is, how fast does your soil drain and how long does it take for the surface of the soil to appear dry? If the soil is staying constantly wet in an indoors environment, I would suspect this may be the cause of your leaves dropping. Especially if it was somewhat happy before the point where you repotted it.

If it has always been kinda unhappy, I wouldn't discount watering, but also have to consider the sunlight requirements for this tree. I've only ever owned one serissa and that was a long time ago, so someone else may be able to advise on how to provide the right sunlight conditions.


My suggestions:

- Make sure your soil mix drains well enough so that it needs to be watered within a day
- Make sure you are not over-watering it to keep the soil constantly damp
- Check to make sure that it is getting enough sun or artificial light to keep it happy

 

[Carmen]

It's hard to tell exactly from photos, but often dark colour at the base of the trunk can be a sign of a trunk which has been kept constantly or frequently wet.

Watering is quite tricky because there are quite a few variables. If you are keeping a tree indoors all the time, the amount of water it requires is going to be different from a tree which is outside in the wind and sun which are going to dry it out much faster. With bonsai, we don't want the soil to stay constantly wet, that's why bonsai soil mixes have larger particles than 'potting mix' so that the roots don't stay constantly damp. We want the mix to retain some moisture, but get to the point where it *needs* to be watered again at some point, usually within a day.

I'm not saying this is 100% a watering issue, just a possibility. The question I get when looking at the pictures is, how fast does your soil drain and how long does it take for the surface of the soil to appear dry? If the soil is staying constantly wet in an indoors environment, I would suspect this may be the cause of your leaves dropping. Especially if it was somewhat happy before the point where you repotted it.

If it has always been kinda unhappy, I wouldn't discount watering, but also have to consider the sunlight requirements for this tree. I've only ever owned one serissa and that was a long time ago, so someone else may be able to advise on how to provide the right sunlight conditions.


My suggestions:

- Make sure your soil mix drains well enough so that it needs to be watered within a day
- Make sure you are not over-watering it to keep the soil constantly damp
- Check to make sure that it is getting enough sun or artificial light to keep it happy

Thanks, that's very helpful. I'd say the top of the soil takes 2-3 days to dry out. I've only been watering it when the very top layer of sand (it isn't sand exactly but I can't remember the mixture at the moment) is totally dry and light in color. It's hard to tell how moist it is because it never feels wet to the touch. I mostly tell by color and whether or not the particles stick to things that touch it. I'm trying to leave it by an open window as long as it doesn't get below 55 degrees F at night. There's also a ceiling fan on.

 

[Wires_Guy_wires]

If only the ends are growing, on any plant, it means it's sacrificing the old foliage in favor of young growth.
This means it's not producing enough energy to keep things alive, and instead is living on borrowed energy from old stuff.

The repotting did it dirty, probably, and it invested a bunch of resources to recover. Now that the roots have recovered, it can invest in foliage again. However, it is a sign that this plant is not in the greatest conditions.

Some LED lights (cool white or plant grow lights) can help it a lot. We don't see it, but windows filter about 20-60% of plant-usable light.

A light/half dose of nutrients might also benefit it. As will a piece of wood jammed into the soil, that can tell you whether or not the soil is dry when you take said piece of wood out.

The trunk made some wood, wood is dead material, and dead material can and will soak up water. The black you're seeing is probably water, combined with whatever is living in your soil (microbial life). This isn't a problem if the plant is healthy. It can be a problem if the plant is not doing great, because that's where pathogenic microbes can also thrive.

If you use the wood to probe your watering needs, and the extra light and a bit of nutrients to power growth, it will probably look a lot better in a couple weeks.

 

[Carmen]

If only the ends are growing, on any plant, it means it's sacrificing the old foliage in favor of young growth.
This means it's not producing enough energy to keep things alive, and instead is living on borrowed energy from old stuff.

The repotting did it dirty, probably, and it invested a bunch of resources to recover. Now that the roots have recovered, it can invest in foliage again. However, it is a sign that this plant is not in the greatest conditions.

Some LED lights (cool white or plant grow lights) can help it a lot. We don't see it, but windows filter about 20-60% of plant-usable light.

A light/half dose of nutrients might also benefit it. As will a piece of wood jammed into the soil, that can tell you whether or not the soil is dry when you take said piece of wood out.

The trunk made some wood, wood is dead material, and dead material can and will soak up water. The black you're seeing is probably water, combined with whatever is living in your soil (microbial life). This isn't a problem if the plant is healthy. It can be a problem if the plant is not doing great, because that's where pathogenic microbes can also thrive.

If you use the wood to probe your watering needs, and the extra light and a bit of nutrients to power growth, it will probably look a lot better in a couple weeks.

What kind of nutrients do you recommend? And should grow lights be on at the same time as when it’s getting natural sun light? Thank you!!