Larch needles ''yellowing'' first year of experience

[Ugo]

Hi everyone!

I'm in my first year of experience with larch.
This is a small European Larch I got a few months ago.

The question as already be asked but due to lack of experience I prefer learning from actual situations as it helps me to better understand instead of assuming I understand.
I was wondering if this can be qualified as sun burn or possible underwatering...
The top of the tree seems to have more pale / yellow needles since a few days.

Little resume:
The reason why I put aside others causes is because I monitor the water needs of my tree each days using toothpicks almost completely planted in substrate.
I had an hesitation on watering the tree 4 days ago as I try to be careful to not overwater.. let say 3/4 of an inch of substrate was dry while the rest of the pot was still humid, semi cloudy day.
I totally underestimated the sun and wind later in the morning and afternoon.
The tree is in a standard 6in black nursery pot and didn't need repotting this year and its sitting on a dark brown bench... I will correct this situation as I'm afraid the roots get cooked during Summer.
When I first got this tree I added coarse sphagnum moss on top of the substrate but that's not touching the trunk thinking it would help to keep up moisture level of the surface roots during heat spells.

When I brought it home it was babied inside a growing tent, the tent was the easiest way to reproduce the conditions in which I bought the tree at the beginning of February.
Let say it had an early start this year!
I brought it outside where the tree is under full sun all day long in zone 5B about 4 weeks ago but this week forecast the first major heat spell we have since the beginning of Spring including the past 4 days.

I would like to know if the tree should be taking out from afternoon sun until I confirm the issue if this is even an issue!?
Can you help me confirm the problem if there's one?!




Thank you and sorry to ask a question that may be obvious for more experienced members!
Ugo

 

[Wires_Guy_wires]

I had this happen twice to a larch of mine. It did not survive the second time. It was way worse than this though. Still not sure if it was the heat, the strong sun or a lack of water.
I think putting it in the shade is a safe option. But I'm mostly dropping a comment to see what others have to say.

 

[sorce]

If it was needled out in the tent, that early "confused" start is the only problem.

Looks like anything that was shaded by the yella looks fine.

IMO...
"Careful not to overwater" means underwatering 9 times out of 10.

Toothpicks are for skewering Japanese Beetles.
Chopsticks are for skewering bigger pests.

Sorce

 

[Ugo]

Thank you @sorce!
Next year will be much more easier for this little tree or atleast much more "normal"...
Unfortunately I was not able to provide better conditions at the time I got it.
The tree was in a greenhouse and with the heat spell we had at the beginning of Febuary followed by very cold temps I didnt know better.

Talking about watering I think this bad habit comes from my maples that are more sensible to overwatering. I will learn!

Thanks again
Ugo

 

[WNC Bonsai]

I suspect water and sun. I lost one seedling in a clump of 5 recently due to that kind of sun scald. A couple of the others in the same pot survived with scattered needle damage like yours. Now I have all of mine in dappled shade. The ones with damage are Japanese larch and they seem mor susceptible to this than my American larches. I have had 10 Americans for 5 years now and all have managed to survive under the same conditions as my J. larch. Of those I have had 30 but have managed to kill 14 of them over the same time period so they cannot be treated the same and I suspect the same is true for your European larch. I have now begun to keep them all in morning sun or dappled shade and go a little lighter on the water with the J. larch but keep my Am. larch pretty wet all the time. I use a pretty free draining mix but do add about 50% pine bark.

 

[Ugo]

I suspect water and sun. I lost one seedling in a clump of 5 recently due to that kind of sun scald. A couple of the others in the same pot survived with scattered needle damage like yours. Now I have all of mine in dappled shade. The ones with damage are Japanese larch and they seem mor susceptible to this than my American larches. I have had 10 Americans for 5 years now and all have managed to survive under the same conditions as my J. larch. Of those I have had 30 but have managed to kill 14 of them over the same time period so they cannot be treated the same and I suspect the same is true for your European larch. I have now begun to keep them all in morning sun or dappled shade and go a little lighter on the water with the J. larch but keep my Am. larch pretty wet all the time. I use a pretty free draining mix but do add about 50% pine bark.

Hi!

Thanks for your inputs.
I think the solution reside in theses 2 factors..
New needles not used to that much direct sun and maybe I was a bit too shy on watering.

Last night just like @Wires_Guy_wires i thought this little larch shouldn't spend more time in full sun all day anyway.
As you suggest I have to adapt to the situation
so I moved it with my Japanese maples which have sun in the morning until about 1pm.
As @sorce suggest, I also think this is due to the tree early start, inside under full spectrum light, while the others conifers we have here just started to buds out.

This week the weather is simply fantastic, full sun with temperatures around 25 deg C.
Basicly doubling the outside temp. from last week and no clouds at all!
I didn't really think about the new needles that are not used to direct sun when I placed it with my other confier, I should have know better as the needles are very fine, complete opposite of my Spruce for example...
I believe this little guy will survive just fine, but I learned the lesson anyway.

As for watering, I believe that using sphagnum moss on top of the pots combined with watering is not a technique that I master perfectly!
Thinking of keeping the top of the substrate cooler without much effort I no longer do a good reading of the water needs of my trees without using toothpicks.
I will therefore simply remove the sphagnum moss, mix it with green moss and put this mixture back on top of the substrate.
I have more experience with green moss on the substrate which I believe won't harm when I check the watering.

Thanks again
Ugo

 

[Cosmos]

Ugo, one tip that has helped me in the past is misting larches during the early waves of warm weather in the spring (and I'm of the opinion that misting is generally useless for most species/situations). The new growth can get dessicated very quickly as you noted, and this week has been relentless for a larch: nonstop sun + wind + unusually dry air.

One advantage of misting larch when it has sphagnum on the soil is you can rehumidify the sphagnum without watering the soil proper, which is good.

Otherwise, giving them maybe 6 hours of sun max these days is not a bad idea. The weather will turn more normal next week.

 

[Ugo]

Ugo, one tip that has helped me in the past is misting larches during the early waves of warm weather in the spring (and I'm of the opinion that misting is generally useless for most species/situations). The new growth can get dessicated very quickly as you noted, and this week has been relentless for a larch: nonstop sun + wind + unusually dry air.

One advantage of misting larch when it has sphagnum on the soil is you can rehumidify the sphagnum without watering the soil proper, which is good.

Otherwise, giving them maybe 6 hours of sun max these days is not a bad idea. The weather will turn more normal next week.

Hi Cosmo!

Thanks alot for your help.
I started misting the tree, removed the tree from its previous location and place it so it get about 6 hours of direct sun.
I will give the back side a little bit more protection for 1-2 weeks and start rotating the tree again.

I did a little work today on this tree, mostly to balance energy within the tree I reduced the long elongating shoots that has produced 6-8 buds down to 2-4 buds.
From now I will pinch the tip of new growth instead of the clip and grow method.

I was stupid with this tree and should have know better then leaving it out in the sun for 12hrs... Poor tree..
I hope it will bounce back and we wont be able to notice the sun scald after the 2nd or 3rd flush but now the top doesnt look as good as it was.

Lets say that Ive learned alot with this event so I will put that mistake behind me and keep this new acquired knowledge to take proper care of this tree in the future.

Thanks again everyone

 

[Paradox]

This larch is weird. I have never seen one with foliage that long

 

[Ugo]

This larch is weird. I have never seen one with foliage that long

Hi!

Yes! Basicaly it looks like how Dr.Seuss would have imagined a Larch!
Its part of its charm and probably the reason why it burn under the full sun

 

[yashu]

This larch is weird. I have never seen one with foliage that long

I thought that as well.

is this an ornamental cultivar?

 

[Ugo]

Very good question guys...
I will ask the nursery I got it from, when I selected it at first it was looking like any other larches but I knew it was not a Japanese Larch.
I was under the impression it was an European Larch but now I doubt it!
I think there is 10ish varietes of Larches..
This one might be Larix lyallii??

​

 

[Cosmos]

The "shaggy dog" look on larches is not uncommun, it's usually a combination of abundant watering and fertilizer, and heat. If you remove a lot of foliage, the rest of foliage tends to explode in length too.