soursop leaves : blackening petiole

[doublemz]

Hi, this is my first post in this beautiful forum. I have a problem with my young seedling soursop tree. I planted it in the ground last April (when it was approx 2 years old). Few days ago, I have noticed a blackening (necrosis?) of the petioles in some leaves (see the attached pictures). The lowest temperature recorded here during this winter season was about 45 F  (8C) until now (during the night). Could it be a cold damage (depite the protection that I used) or is it some thing else? Thank you for your help.

[Tommyng]

Yes, that’s likely cold damage. Winter is a bad time for soursops, mine have almost no leaves. If it gets in the 20-30’s you should bring them indoors or keep them warm.

[pineislander]

At temperatures near 40 degreesF the soursop will drop it's leaves. If it doesn't go much lower the tree will refoliate as weather warms. Repeated defoliation can weaken the tree so beware if it refoliates before winter is over. Reducing cold wind blast  by sheltering it will help the tree hold leaves.

[FV Fruit Freak]

Yes, that’s likely cold damage. Winter is a bad time for soursops, mine have almost no leaves. If it gets in the 20-30’s you should bring them indoors or keep them warm.

Agreed, it’s the cold. But I would bring it in way before it gets into the 20’s/30’s(F), as it may be too late by then. Looks like we’re In the same climate doublemz. My 18” inch soursop seedlings (in a pot) leaves started to turn black and fall off as our night temps have dropped into the 40’s/low 50’s (lowest it got has been 42F) I brought it inside about two weeks ago as I noticed leaf blackening/fall off. Where the leaves fell off, new leaves/nodules are already forming. I would get that thing wrapped up in a thick blanket and maybe throw some Christmas lights on it. Good luck.