Concerns a overwatering Shimpaku Juniper

[jtskariah]

Hey everyone,

I live in Georgia so the weather has been pretty sunny lately. I usually water my juniper about once a day. It appears to be in good bonsai soil (akadama from the looks of it) but I am concerned I may be overwatering the tree. When I go to the tree I look to see if the akadama is dry on the top (light brownish color) but when I dig a bit deeper the akadama is darker. But I do not feel much moisture and it still appears dry however the color under the top layer is a darker shade for sure. I do water when I see most of the top layer as a light color. I ideally want to water in the mornings around 9-10am but I heard that you should wait until the tree needs water. Sometimes when the tree appears to finally dry out (top layer is a light color) but it’s closer to 6-7p at night. I know these trees are very particular and if you miss watering it could impact the tree significantly. So I water the tree closer to night if I see it needs the water sometimes. Is this the recommended practice or should I just wait until the morning? I do not want to overwater the tree so I am being careful. When I do water I’m very thorough (3 passes with watering can with full soak until it runs out drainage hole for a while). Currently the last time I watered was day before yesterday. Yesterday’s weather was very cloudy so when I checked this morning the soil is still dark. I plan to hold off until later this evening when the soil lightens up (the moss has dried though). I am very curious to proper watering technique to be doing this correctly. I have watched so many videos and read so many threads but it’s very difficult to gauge sometimes. The akadama looks dark at times but when I feel it it seems so dry. Is the top layer being dry enough to signal to water without worrying about the layer underneath? I want to be sure to care for this juniper properly. I included some pictures of the dark akadama this morning for reference. Your advice is appreciated.

 

[HENDO]

You can let that soil dry out until it also looks dry even ~1/2"-3/4" below soil level, no problems doing so with my junipers here in Houston at least. Sometimes when I have difficulty gauging soil wetness I look at the inner sides of the pot and see if they are wet, as the akadama seems to perspire and keep it wet.

I would also get rid of that sphagnum moss on top. A layer of sphagnum moss sifted or chopped into a finer size may be placed as a top dressing to keep the top layer moist and encourage root growth for recently potted/repotted plants - I personally don't do this with my junipers as I like them to dry out, only with deciduous.

 

[HENDO]

Forgot to mention that yes you should definitely watch your soil and ensure it is drying out before watering rather than just watering in the AM/PM at certain times.

Your soil looks like good free draining inorganic which is great - some pumice in there might be nice once you repot.

I like your thorough watering technique. 1 or more passes until it runs through the drain holes. My junipers seem to like relatively "aggressive" watering.

 

[jtskariah]

Thank you for the information! I removed the remainder of the moss today and watered carefully. That’s really helpful. My concern is when the soil looks like this. We can see that the top layer is dry but I dig a bit deeper and there is still some discolored soil. This is honestly longer than I usually wait to water. Most of the time I water a bit before the soil looks this dry. Is it safe to water when the soil is like this or should I still wait a bit. I watered this today at around 3pm.

 

[jtskariah]

I will say that the tree appears to be healthy. I used bio gold fertilizer along with fish emulsion foliage spray every two weeks. I see a lot of growth tips throughout. But does the top look a bit discolored to you guys? I will attach some pictures below with some close up shots. Hopefully the watering routine is not harming the tree

 

[Brian Van Fleet]

I’m watering junipers about every other day right now, due west of you. Your photos show a tree that, to me, wouldn’t need water before tomorrow afternoon. Remember, (and when you start repotting, you’ll see) that trees don’t need to be wet, they just need to have some humidity and good air exchange. Soil that doesn’t seem wet will still have very healthy, not dry roots. If you’re nervous about underwatering, you can always “mist” the soil surface and wait until the next day to water thoroughly.

Here is a good example, this is the top of an itoigawa after I scraped away the top layer. Looks pretty dry, right?

Now look at the bottom of the root ball...plenty of moisture to get through the day.


Also, junipers are really not that picky...and will do better on the slightly dry side anyway.

 

[sorce]

Seems more like a tight wire or broke branch than watering woes. Stress from wiring before pests but, solo plants on decks are quite susceptible to mite infestation since, coming off a wind gust and landing there, it's the only game in town. But I don't feel it's pests.

Keeping a more local J species up there too may not be a bad idea, since you can see pests there first.

The dark coloration on the base worries me.

You know how long since it's been repotted?

Could be due.

Sorce

 

[PA_Penjing]

I was also noticing how dark and damp the surface roots seem. Looks to me like the akadama has broken down a little bit closest the rootball

 

[jtskariah]

Thank you Brian for that useful info! It looks like I can be a little more patient when it comes to watering. I may have to water every 2 days instead of every day for now. It rained today so the tree received a bit more water. I have moved it under the cover of the deck roof so it's away from the rain for now. Those images are really helpful! I heard that junipers prefer to be a bit drier but I also heard that having a tree that is underwatered even one time could kill the tree. That has me a little on guard. Thank you for the help!

 

[jtskariah]

Seems more like a tight wire or broke branch than watering woes. Stress from wiring before pests but, solo plants on decks are quite susceptible to mite infestation since, coming off a wind gust and landing there, it's the only game in town. But I don't feel it's pests.

Keeping a more local J species up there too may not be a bad idea, since you can see pests there first.

The dark coloration on the base worries me.

You know how long since it's been repotted?

Could be due.

Sorce

I was also noticing how dark and damp the surface roots seem. Looks to me like the akadama has broken down a little bit closest the rootball

Hopefully so! I am watching this tree very carefully, I want to be sure I am not harming the tree so the slight discoloration/yellowing appearance near the top branches has me wary. Hoping it does not progress, and if it does what I can do to stop it,

I don't think it's a pest issue as of now but I can't be sure. The tree should still be under the influence of Bayer insecticide so that may or may not help.I don't see any visible signs but I will look a bit closer to determine.

In regards to the root ball, when I received the tree it came this way. There was moss on that section (that I removed). It stays dark most of the time but obviously gets much darker when I water the tree (as seen in the picture). I was told that repotting is due next year. Not sure if they decided to elevate the bottom portion for aesthetics or if the akadama broke down. Do you believe this tree can wait until next year to be repotted or is this something that could be urgent? Is there anything I should do about the rootball in the meantime?

 

[PA_Penjing]

without knowing the tree's history and how well the soil is draining I couldn't advise you repot or wait. I think the best thing you can do right now is to start watering when the tree needs it not on a schedule. BVF gave you a pretty great break down on that. It's not wise to repot a stressed tree, so next year seems better based on that alone. Junipers are pretty cool, in that they tell you when you can perform bigger opertions. They will have vigorous spike growth when they are happy and have stored energy, that tells us we can have fun. So I would try to get it there first.

 

[BonsaiDTLA]

Thank you Brian for that useful info! It looks like I can be a little more patient when it comes to watering. I may have to water every 2 days instead of every day for now. It rained today so the tree received a bit more water. I have moved it under the cover of the deck roof so it's away from the rain for now. Those images are really helpful! I heard that junipers prefer to be a bit drier but I also heard that having a tree that is underwatered even one time could kill the tree. That has me a little on guard. Thank you for the help!

More often than not, especially with substrate typically used for bonsai, people overwater rather than underwater their bonsai.

You can go a couple days in between watering assuming the weather isn't crazy hot and drying out your soil big time.

 

[jtskariah]

without knowing the tree's history and how well the soil is draining I couldn't advise you repot or wait. I think the best thing you can do right now is to start watering when the tree needs it not on a schedule. BVF gave you a pretty great break down on that. It's not wise to repot a stressed tree, so next year seems better based on that alone. Junipers are pretty cool, in that they tell you when you can perform bigger opertions. They will have vigorous spike growth when they are happy and have stored energy, that tells us we can have fun. So I would try to get it there first.

More often than not, especially with substrate typically used for bonsai, people overwater rather than underwater their bonsai.

You can go a couple days in between watering assuming the weather isn't crazy hot and drying out your soil big time.

That is great info. I will be sure to be more patient when it comes to watering. One thing I will note is that I do not see any pests on the tree and I inspected it very carefully. So that problem hopefully is clear for now. I will hold off on watering but there appears to be a storm coming to Georgia.. I am moving the tree so it is not getting continuous rain for the next few days. In regards to the tree.. does this appear healthy from the pictures? Or does it look stressed in some way? I cannot really tell if the top is yellowing or not, it looks different depending on the lighting conditions and I am unsure if this is just normal growth. I am happy to provide any additional info or pictures. I am sure you can already tell.. I am doing my very best to keep this tree thriving. Lucky to have this community for guidance, thank you!

 

[sorce]

I was told that repotting is due next year.

I'd watch the Mirai Youtube on the 4 reasons to Repot, in order to determine how "scheduly" that advice was.

The one thing good about having no fear in putting a tree in a shallow pot, is that a shallow pot doesn't have such great a differential in wetness top to bottom.

I keep mine in a right shallow dish, so I couldn't advise any further from personal experience.

It would seem possible that the live vein and lower roots feeding that portion are in old soil in the core of the tree, which you may be able to gauge with a careful pull out, maybe a toothpick?

Truth though, I love that virt without that part, so I'm biased.

Just make sure it doesn't travel to the other branches.



If you can watch your tree so closely you see it grow, you will know what ails it.

Sorce

 

[PA_Penjing]

I don't have enough experience with shimpaku to guide you here but the foliage color does seem off to me. All of mine are a nice green now and so are the ones at our nursery. Even when they had "winter color" it was bronze not yellowy. Hopefully it's just from being over watered and will green up in time. It seems to me that you may lose a few outer needles/leaves at this point. Usually mite damage will look more gray and dull not quite yellow, regardless you won't see mites with a naked eye until they are fully grown and the infestation is bumping along.

 

[PA_Penjing]

Just looked over the photos again and noticed how many greenish needles are laying at the base of the tree. Did you cut or hand pinch those off? Or did they fall off of the tree on their own?

 

[jtskariah]

I'd watch the Mirai Youtube on the 4 reasons to Repot, in order to determine how "scheduly" that advice was.

The one thing good about having no fear in putting a tree in a shallow pot, is that a shallow pot doesn't have such great a differential in wetness top to bottom.

I keep mine in a right shallow dish, so I couldn't advise any further from personal experience.

It would seem possible that the live vein and lower roots feeding that portion are in old soil in the core of the tree, which you may be able to gauge with a careful pull out, maybe a toothpick?

Truth though, I love that virt without that part, so I'm biased.

Just make sure it doesn't travel to the other branches.



If you can watch your tree so closely you see it grow, you will know what ails it.

Sorce

Makes sense I will watch those videos and learn a bit more. I watch a lot of Mirai videos, they are a great resource! I will cut down on the watering but I have bad luck as there is a very big storm in GA for the next few days!

 

[jtskariah]

I don't have enough experience with shimpaku to guide you here but the foliage color does seem off to me. All of mine are a nice green now and so are the ones at our nursery. Even when they had "winter color" it was bronze not yellowy. Hopefully it's just from being over watered and will green up in time. It seems to me that you may lose a few outer needles/leaves at this point. Usually mite damage will look more gray and dull not quite yellow, regardless you won't see mites with a naked eye until they are fully grown and the infestation is bumping along.

Just looked over the photos again and noticed how many greenish needles are laying at the base of the tree. Did you cut or hand pinch those off? Or did they fall off of the tree on their own?

Those needles are there from the previous owner who pruned the tree before I received it (roughly 2-3 weeks ago. I will need to go and remove them with pliers soon but I don't see many leaves falling off as of now. I always thought it would take months of overwatering for the tree to start turning yellow. I did not have the tree for very long, I hope it has nothing to do with fertilizer as well.

 

[jtskariah]

This was earlier today. Hopefully there is time to help it recover after this storm

 

[sorce]

will cut down on the watering

That's not a good idea 95% of the time. Not that you may not be in the 5%, but it's not worth saving that top garbage to risk the rest.

Besides, I don't think it's a water issue, if it's even an issue.

Sorce