Frost damage on Poncirus and Citrange

[mikkel]

This winter my Poncirus has the same damages as my Citranges. we had nearly no frost this winter but some cold nights in early spring. Citranges and Poncirus were fine before but have now the same damages.

Colder winter were better for both.

Poncirus

Citranges

[Laaz]

Your problem is that your tree's never went dormant. When the sap is flowing & freezes, the bark & new growth are damaged.

[kumin]

Mild winters can be as harmful as cold ones. A local peach farmer has lost 2 consecutive crops. 2018/2019 to a servere cold winter. 2019/2020 to a mild winter and spring freezes. Our area has freezing temperatures forcast by weekend again. Keeping the Polar Vortex in the polar regions all winter appears to have consequences in springtime.

[poncirusguy]

I live in the inner city of Cincinnati where I will clear frost by 1 F because of a +5F micro climate zone pushing me to zone 6B

[david]

Mild winters have drawbacks too. When poncirus is not fully dormant it will get some damage as will the hybrids. Will not kill them and mostly light damage.

[ilya11]

Mikkel, I see a similiar damage on some of my ponciruses. It is strangely localized only on some parts of the same plant.

Last summer because an effective snail killer was banned here I had  big problems with these pests, in late summer they prefer to eat not the leafs but twig skin.

I believe that combination of such damage and occasional winter frosts are producing these lesions.

[roberto]

I think it is crucial to keep stem-protection and mulch until there is no danger of night frosts. If you have high temperatures in March this could wake up the plant completely and makes ist thus vulnerable to frost. If I keep the soil cold (under the mulch it won't warm up too early) and avoid sun exposion of the stem the tree will take late frosts better. I did not have problems at -5°C to -6°C. The lowest temperatures of the whole winter in -spring!!