Q. We have a question about our 5- 6 year old naval orange tree. For the past 2 to 3 years we left the fruit on the tree until the weather man said freezing temperatures were coming. But with just cold nights, the fruit seems to dry out. Can we pick the fruit early and let the oranges ripen in the house?
A. Just a note. Navel oranges are real tricky here in southern Nevada. They have to be planted in just the right microclimate or they will freeze. I forwarded this question to my counterpart in Phoenix, Terry Mikel, for a response.
Navel Oranges tend to be a bit persnickety especially when they are young, no matter the cold, heat or whatever. If you are seeing lots of leaves and small branch damage, then frost will be an issue.
Freezing nights will dry out any citrus fruits. The juice inside freezes and crystals rupture cell walls and the juice simply drains out. The problem with citrus, if the fruits aren't ripe on the tree, they won't ripen any more off the tree. Sorry.
There is another possibility and I am hoping that the 'damage' is due more to being juvenile and not as much due to freezing damage. If the leaves aren't hurt by the freeze, then the fruits wouldn't be either. As the plant gets more mature, there will be more “metabolism” going on and thus better fruits.