treating sunburn damage?

[Maui Palm & Tree Care]

im trying to crown restore 2 grevillea robusta trees that have been topped 2 years ago. the 2 main leaders on one of the trees, were subject to intense hawaiian sunlight and are showing signs of major sunburn with cambium deterioration and ant infestation in the affected areas. if you got any neat ideas to share, please do.

 

[Jeff_Cochran]

the proper term is sun scalding

 

[Maui Palm & Tree Care]

thank you jeff. ill use sun scalding from now on.

 

[Jeff_Cochran]

http://en.wikipedia.org/wiki/Sun_scald_(flora) do you ever use Google?

 

[tomthetreeman]

Sun burn and sun scald are actually two different conditions. Joshua is probably dealing with sun burn, which is a condition where the interior canopy is suddenly exposed to sun after a storm event or being topped. The conditions look very much the same, and to be honest, I don't know how different they are physiologically.

-Tom

 

[Maui Palm & Tree Care]

is there any way to treat it once it has been effected? i really wanna save these trees and so does the Home owner.

 

[tomthetreeman]

Other than improving soil and other surrounding conditions, no. The affected area generally becomes a decay site, and judicious pruning is the treatment.

-Tom

 

[oceans]

Could a temporary mesh covering limit exposure until the canopy fills back in? I agree with Tom. I would apply a decent mulch layer to retain soil moisture if it isn't there already. Monitor soil moisture and water as needed. Keep unwanted growth in check in the meantime...

 

[tomthetreeman]

Eric, I think that's a great idea if done right away. Once you see the damage it's usually too late for preventive type stuff... The tree has already adapted.

-Tom

 

[oceans]

It does sound like it's a bit late for a covering. For some reason, I was reminded of a lecture that briefly covered the topic of treating cambium damage with immediate covering. "Immediate" being the key word...

 

[treesandsurf]

I don't think I've seen one tree that I thought couldn't be 'saved' because of sun scald. Also, robusta has very thick bark and is usually less susceptible to this type of damage IME; are you sure it isn't a canker or some type of fungal problem?

If anything, you may have to do some reduction work if the injured area has lost significant strength (structural). Photos!

jp

 

[guymayor]

[ QUOTE ]
I don't think I've seen one tree that I thought couldn't be 'saved' because of sun scald.
If anything, you may have to do some reduction work if the injured area has lost significant strength (structural). Photos!

[/ QUOTE ]

Agreed. Covering could be done until the shade is restored by other means. I've used silver or white paint too.

Nitpicking terms is pointless. Sun damage by any name; it's what we do about it that matters.

Cameras are important tools.

 

[mdvaden]

[ QUOTE ]
the proper term is sun scalding

[/ QUOTE ]

Several years ago, I wrote an article for the Online Seminars for Municipal Arborists.

The article was about two distinctly different damages.

1. Sunburn

Generally warm and hot season damage from sunlight reaching susceptible bark.

2. Sunscald

Usually cold winter injury caused by freezing following some warmth earlier in the day.

******************

The results of the damage are similar in many ways. Although I'd say, at least in Oregon, 90% of trees damaged by one or the other, are damaged by sunburn.

The sunburn often does more damage here, because some people prune too much in the growing season, exposing upper branches and stems to sunlight enough for damage to happen.

So newly planted trees sometimes get sunburn when the trunk is not protected. And if adjacent trees or foliage is removed, that causes the problem.

The remedy or salvaging of trees with sunburn simply depends on which tree, where the damage occurred, and how bad it was. Some are keepers, others are weepers.

Odds are, most damage is done, and any bark not killed already, had been acclimated. But even deadwood and unwanted twigs provide shade. So you might consider doing follow-up pruning to the canopy in the middle of whenever your cool season is. Treatment would be similar to pruning, which is don't use wound seal and likely no good to try and carve deadwood away.