Is this sunburn on my Hornbeam?

[Evans]

I’m wondering if anyone has the answer to this. I’ve noticed some new growth on my Hornbeam has started to develop this brown edges to them. The edges while brown, are not crispy or dry when they first develop.

My tree is kept in the shade for as long as possible throughout the day, but gets sun from around 4:30 to 6:30 each day. the soil is kept moist, and watered when it starts to dry out a bit. I thought the tree may have a fungus issue so I sprayed it with fungicide late one evening during dusk a few days back.

Does this look like sunburn or some other issue to do with fungus or roots?

 

[penumbra]

Not sunburn, that much is certain.

 

[Evans]

Not sunburn, that much is certain.

What do you think is the more likely cause?

 

[ChristianDGreat]

Sunburn should be brown at the tip, correct?

 

[Evans]

Sunburn should be brown at the tip, correct?

As far as I’m aware sunburn can effect any outer portion of a leaf. I may have learnt wrong though.

 

[Forsoothe!]

Too much water in too little or not intense enough sunlight brings excess water and salts to the growing edges of the leaf where they accumulate to toxic levels instead of being used because of insufficient light. Put full sun trees in full sun, or else.

 

[Evans]

Too much water in too little or not intense enough sunlight brings excess water and salts to the growing edges of the leaf where they accumulate to toxic levels instead of being used because of insufficient light. Put full sun trees in full sun, or else.

But hornbeams are not full sun trees. They are natively under-canopy trees so the prefer shade.

 

[Forsoothe!]

If you say so. Keep of Truckin'...

 

[HardBall]

I have one doing the same thing in full sun. I'm pretty convinced it's too much water. Mine is in too big of pot.

 

[Moridin]

I really don't think it sunburn as mine sits in full sun with no issue at all.

 

[Forsoothe!]

¿How different is C. caroliniana from the Korean here?...

 

[VAFisher]

I keep my American hornbeam in full sun without any issues but Im not convinced shade would cause what you're seeing. I would guess fungal.

 

[Evans]

¿How different is C. caroliniana from the Korean here?...

View attachment 380088

Let me pose another question to you. My hornbeam is a yamadori (dug up from a forest on someone’s property). Would my hornbeam genetically be more susceptible to sun and wind than a hornbeam that has been grown in more exposed conditions?

 

[Forsoothe!]

Let me pose another question to you. My hornbeam is a yamadori (dug up from a forest on someone’s property). Would my hornbeam genetically be more susceptible to sun and wind than a hornbeam that has been grown in more exposed conditions?

I don't know. Maybe someone else does.

 

[Moridin]

Was it just dug up? Than possibly but if it's been in a container for a while no.

The one I posted a picture of sits in full sun in 80-100 degree temps no problem.

 

[Evans]

It was dug up and grown for a year in a greenhouse with about 50% sunshade overhead. So it’s seeing full sun for the first time ever really.

 

[Evans]

Was it just dug up? Than possibly but if it's been in a container for a while no.

The one I posted a picture of sits in full sun in 80-100 degree temps no problem.

It was dug up and grown for a year in a greenhouse with about 50% sunshade overhead. So it’s seeing full sun for the first time ever really.

 

[Potawatomi13]

Have one Japanese Alpine Willow which can do this on hot days. Firmly believe just cannot get enough H20 to leaf edges quick enough to prevent cell death. However these alpine low growing trees do grow naturally in very sun exposed places.
What is your location? Please add to profile. Perhaps is not sun burn but this.

 

[Forsoothe!]

It was dug up and grown for a year in a greenhouse with about 50% sunshade overhead. So it’s seeing full sun for the first time ever really.

Well now, that's pretty important information, without which the conversation doesn't make any sense. There are no species of anything that will not burn if brought from inside in full leaf to outside in one felled swoop. It has absoposilutely nothing to do with characteristics of the species, you haven't given it the exposure typical of the species. Everything has to be re-introduced to direct sunlight in steps: shade, dappled or bright shade, partial sun, more sun, full sun. A few days at each stage and Viola! No problemo.

Lesson to greenhorns: Don't ask partial questions; present all the specifics you have, then ask for advice.

 

[Forsoothe!]

Have one Japanese Alpine Willow which can do this on hot days. Firmly believe just cannot get enough H20 to leaf edges quick enough to prevent cell death. However these alpine low growing trees do grow naturally in very sun exposed places.
What is your location? Please add to profile. Perhaps is not sun burn but this.

Are we talking about Salix arctica? The Arctic willow grows in tundra and rocky moorland, and is the northernmost woody plant in the world, occurring far above the tree line to the northern limit of land on the north coast of Greenland. It doesn't get "hot" in its native zone close to the suface of the "land" where this low-growing shrub lives. No wonder it can do poorly in Oregon zone 7?