Pick oranges now or wait? Here's how to know

Growing citrus can be, as I noted once, like keeping a pet cat: You love it, but rarely understand it. The trees follow their own calendar, which is nothing like the timelines for cherries or apples. The master gardener help desk often receives questions about citrus trees or fruit from perplexed homeowners.

Some citrus can be used at various stages of ripeness -- limes being a good example -- but navel oranges need to be fully ripe to be enjoyed.

So how to tell? There are clues: They should have full color, be heavy for their size, and be firm but not rock-hard -- they should give just slightly when squeezed.

But by far the best test is tasting one, or two, really: One from each side of a full-size tree. (One from a container tree should be plenty.) If it doesn't taste ripe, wait a week and try again.

One of my neighbors traditionally picks all her oranges on Christmas Day. That to me is a gamble -- and unless she gives most of the fruit away, creates other problems. Storage, for one. (If you must: Keep them in boxes in a cold garage, in one layer. Or juice them and freeze the juice.)

Also, citrus does not ripen off the tree, so whatever stage that fruit was in will be the stage it stays in, until it's eaten or rots.

"Storing" the fruit on the tree is generally the best move, with one caveat: If a hard frost is expected, pick all the ripe fruit before the cold hits. Make sure the tree is well-watered, too. Orange trees can survive temperatures down to 21 degrees, but the fruit may be damaged below 27 degrees or so, according to the UC Cooperative Extension experts. (The Sacramento master gardeners' Garden Note 127, "Growing Citrus in Sacramento," has a wealth of information. It can be found via "The Home Orchard" page on the master gardeners' website; it's the first link under Master Gardener publications and videos.)

"Citrus sensitivity to cold also depends on how long it stays cold, whether the trees are exposed or in a protected area, whether the trees are in a low area where cold air collects, and how old the trees are," the information also explains.

So become familiar with the timeline for your own tree or trees, noting the changes in the weather as winter continues. And enjoy those gorgeous oranges you've been growing all these months!