Is this sun scald?

[vnomonee]

Some of my hardy citrus have this white almost blistering on the stems. This is the only apparent damage after 5f over the weekend.


Ninkat x poncirus





Prague chimera

Only on the upper leader, lower branches are unaffected. Looks much worse in the picture for some reason lol

[Millet]

Doesn't look like sun damage to me.  Looks more like insect damage.

[David Kipps]

It does look like the motley appearing stems on my borderline hardy citrus after severe cold.  If no more strong cold they recover, but too much and they die and bleach out.

[tedburn]

I also have these white spots on some of my coldhardy in garden planted citrus after -13 ° C. Especially on the twigs of late summer, which are not fully hardened. But I agree that in combination with wintersun the damage gets quickly worse.

[vnomonee]

The backside of the same growth looks unaffected on the Prague, I suspect the Ninkat x Poncirus as well. These are the top most growth spurts so must not have been hardened enough. My most damaged Yuzu has bleaching on the upper branches they are completely white. A shaded out Yuzu cutting from the same plant does not show the same damage




Here's the Yuzu exposed to full sun and the damage



Same plant rooted cutting but in mostly shade, not nearly as much damage except the one twig

[kumin]

I find similar damage on late growth that hasn't sufficiently matured for winter survival. Sunlight may indeed bleach the damaged twigs.

[vnomonee]

This is what ended up happening to the prague stem with the sun scald. The back of it still has some green. The lignified stems on the Prague have minimal if any damage