Hello Forum Friends! I’ve got an Atlas Cedar (in refinement) Must be at least 30yrs old, I’ve had it half that time with no issues. Last repot was maybe 4 or 5 yrs ago. We’re in a new environment; partial shade/sun. Water seems to percolate ok. But needles are yellowing and abandoning ship on several branches. I have no idea what it’s asking for: more or less water, sun, a repot, or medication? I’m worried. Pictures may be inadequate as there’s little room to stage good background. Can you help determine what might be going on here?
It’s hard to tell without a photo. Do the best you can with the background you have - maybe hang up a white sheet behind? Closeups of affected foliage are helpful.
It may just be that it’s time for the old needles to go and the tree is compartmentalizing them off. I’ve had needles yellow on my cedars in the past month. If it’s not just the older needles, then it may be something else. I’m in Northern California and keep mine in full sun, BTW.
If the last repot was 4-5 years ago, sounds like it’s time for a repot next winter/ spring. Can’t hurt, might help.
Hi, Maryann. Thank you for your response. I did take photos but couldn’t figure out how to upload them to the site. (Android cell phone to Mac computer). It’s beyond my tech grade 
I agree it would be better to show them.
Also agree that a repot would be in order, but I guess I’ve missed the timing for that, too. Unless it’s an emergency maybe, (I also live in northern CA.) do you think it’s out of the question?
The tree has new growth that seems to be on pause; while this yellowing is moving in from the tips more rapidly, leaving branches bare. I hate to lose this tree from ignorance.
We have a Cedrus that has been shedding branches. Most likely the caus was nursery soil in the sheen, the nursery mix has been removed and so far it seems to have stabilised and is growing healthy. Yes I would say you missed the window for repotting. You could try the vacuum method that Ryan show in one of the videos to explore the soil near the trunk as that would be the most likely problem. Entering a chopstick in the core could help determine the soil humidity before water (balance water and oxygen).
Pictures would help to rule out a pest problem.
Thanks Robert. I appreciate your supportive suggestions. ( I wish I could figure out how to share my photos. I’ve been trying for hours.) But will try the chopstick method for soil humidity. Really hard to tell what’s going on in the sheen. We had such a long, wet winter this year. I think it just needs a repot as the soil is feeling solid clay (old Akhadama). Going to do some digging around to see.
Have you tried cal king, c4 and nitrogen?
Yellowing can occur from a lack of calcium and nitrogen
And also a lot of other reasons
What are you feeding it?
You could try this
Take screenshot of the pictures on your phone
Email or messenger them to the ipad, save to photos
Then upload them here
Or vice versa if you are going the other way
Sometimes screenshots can side step a tech issue
So kind of you to help me out with the photos as well as the tree, Chris! I will try your suggestions.
Asap.
I’ve fed the trees with dilutions of MAXSEA for years. Quite possible there’s an imbalance in the soil.
First, the photos then the food. Will get back to you…
Do you have anything to test the soil Ph?
The yellowing from a lack of calcium and nitrogen is typically pH related, too high or too low of pH you will get nutrients lock out or lock up.
Somehow, through trial and many errors, I got this photo to post. (Not likely I could repeat it.)
After listening to Ryans latest podcast ‘Spring Recap: Bonsai Nutrition’ as well as Chris’s and NEBeech’s suggestions on nutrients, I’ve concluded it’s probably a lack of balanced nutrition and possibly toxicity build up. There was a related post that described this phenomenon exactly. I’ll try to find it again. I’ve been lucky to have healthy trees throughout the 30 yrs of caring and collecting them, but i was and still am rather ignorant on horticulture. Returning to Mirai Live for
more instructions. Gratitude for everyone’s help.
You said you are in a new environment
Did your water source change? Did you move?
There are others here far more knowledgeable then me, so hopefully they can help you out.
Glad the photo trick worked for you
My trees look healthy however after getting my first Apical tests back last night I can see I am very low on calcium which doesn’t shock me as I have never added it before ( other then what was in Bio Gold)
If you moved, changed environment, changed water source, etc there are a lot of variables.
It might point to the Water quality or PH of the water.
$10 test kit or $10 ph meter could help you figure out the PH if you have not already tested it.
Best of luck
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I agree the water is the most likely variable after 30 years of no issues. I had a similar issue last summer (nutrient lock out) after using the hose with no filter (water pH is 8.0) after only about 3 weeks with no rain water to supplement.
Good luck with it 
Thanks for your support. You may know how rare it is to get to talk with other Bonsai lovers in everyday life. How great to have this forum!!
I did indeed move last September and we had an enormous amount of rain that I could not shelter the trees from. Some plants actually drowned 
Just got a filter for the hose a month ago. But the trees all suffered a few months this Spring of our horrible city water. I will invest in the tools you suggested. There’s no calcium or magnesium listed in the MAXSEA plant food I’ve been using. Didn’t know they were needed by the trees. I have lots of Cal/Mag supplements for myself (hard enough trying to create THAT balance, lol, now I’ve got to worry about the trees getting their suppies!!). Seriously, do you think I can use the supplement powders I have on the plants as long as they’re purely Cal/Mag??
I would think they are different nutrients
And honestly I would start with the PH as others have suggested
If it is high, it can be lowered with regular white vinegar and testing with the cheap kits to get you as close to 6.4 as possible
If it is low there are PH up product to raise the PH
It is probably stressed from the move, the excessive rain and perhaps a new water source that is not what it likes.
I think that would be the quickest and easiest place to start.
I think Mirai has said most trees need calcium and Eden certainly seems to recommend it for Bonsai but as others have pointed out, it was happy before the move.
So the water is a great place to start.
Sorry about your drowned trees, that is horrible
Good luck
There are far more expensive and better products on the market but these could easily and cheaply give you a idea if you PH is way off.
I use them both to check for consistency and accuracy
Digital meter need calibration occasionally
Chemical tests always work but are not as accurate
Chris, this is such a help! If this Cedar lives, I’m gonna post it on the Mirai App and name it after you!
Chris - Thanks for the pointer to the API test kit. I have found that the low cost digital systems tend to go wonky. I have used a pH down product for hydroponics which is phosphoric acid based with good results. That is a macronutrient which is nice, but it can tie up iron if the pH is too low.
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I have been adding a cap full of PH Down to lower the water PH , my Well is pumping higher PH now than 10 years ago. I see the soil dry out better having made this change, Of course now I can water - no more hose. The capful in 2.5 gallon cans gets it to high 6.8 Learned from Bjourn and it requires it to be an every day regimine - not once in a while.
Did you wire the tree recently? Cedrus is fairly brittle so it might be (part of) the problem.
No, it’s been wired for some time now. I leave it on to support the long branches that are, indeed,
delicate. I inherited this tree well over ten yrs ago and a couple of others in pretty bad shape from neglect, so I have no way of knowing how old it is, I think it’s pretty old, and been through a lot.