My aunt has long grown the Washington Orange and the Meyer Lemon, outdoors in Novato California. Novato's climate is similar to ours, but she occasionally has frost damage even there. And, since Portland's winter low temeratures, are a little colder than Novato's, those varieties probably wouldn't do well here.
However, I've been doing my homework, and I have determined that there are several citrus varieties that should be able to survive outside, here in Portland. Among them, are the Owari Satsuma, the Changsha Mandarin, Mr. John's Longevity Citrangequat, the Nippon Orangequat, and the Shangjuan.
Most of these fruits were field tested in a Coastal Georgia Study, and they actually survived well, at temperatures a bit colder than those we normally have here. Well, colder than temperatures where I live, in NE Portland, anyway. In a sheltered location, with covering in really extreme weather, I'd barter that these tree might survive for a lifetime.
I'm providing a link to the field test study. And would like to hear if someone has firsthand experience with growing any of these trees locally.
http://www.walterreeves.com/up.....citrus.pdf
The survival temperatures listed for citrus trees are usually for late winter temps. An early freeze can kill these trees at a much higher temp than listed. They must have time to acclimate to the lower temps, Also you should investigate the possibility of a microclimate where your aunt’s trees are planted. There are many cases of citrus surviving in areas where they should not and all were found to be located in one of these micro climates.
Owari’s are good for about 20 degrees late in the season and the kumquats can take around 12 degrees. 27 degrees for 8 hours will kill a Hamlin orange and the lemons are easily killed by a lesser freeze.
If you go with this I would install micro sprayers at a height of 27-30 inches above the trunk that emit approximately 20 gallons of water per hour. This will not save the whole tree but it will save the graft and part of the trunk. After a bad freeze the tree will grow back rapidly from the damage after pruning.
Karl
Thank you for your response. I am planning on trying some of those trees here in Portland. Dispite our being fairly far north, we are at the confluence of two great rivers, at an elevation of about 100 ft, and the climate here is generally moderate.
Further, my house has a southern wall with a large overhanging eave, and temperatures in my neighborhood seem to be about 5 degree warmer than those posted under the open skies at the nearby Portland Airport.
I believe the actual low temp this year at my house was not lower than 25 F. It has also been about ten years since this area has recorded a temperature near 15.
That's not to say this is a wonderful location for citrus, it's very borderline. But, with my southern wall, the most frost hardy plants, and a little care, I'm hoping to pull it off.
I am growing kumquats, Meyer Lemon, limes, and mandarin oranges that are inside right now and 10 degree tangerine, yuzu, and ichang lemon outside. They are all doing ok. Most people around here would put most citrus on flying dragon root stock so they can take it in when it is really cold. That is my plan too, for all the things that are inside right now. There is another guy in my neighborhood who grows kumquats and Meyer lemons. They aren't uncommon around here.
John S
Portland
The parent Washington Navel Orange tree is about three blocks from my house here in Riverside, CA, but the last freeze in January still killed a lot of citrus around here (but it didn't hurt my apple trees one bit).
So who's crazier, me growing apples in a warm climate, or you poor guys in the Northwest growing citrus? I think I have it easier. But keep on trying guys and don't give up.
But to be fair, the reason Washington Navels do so well here is the same reasons apples do well in Washington. Our dry climate has fewer diseases, and the weather when they're ripening in December is warm clear days and cold nights right above freezing, which colors them up better than the ones from Florida. But if the weather drops a few degrees more, it's a billion dollar disaster that puts thousands of people out of work.
Incidentally, this same weather gives us outstanding late-season apples like Fuji, Pink Lady, Granny Smith, Sundowner, Gold Rush, and Lady Williams. They hang on the tree two months longer than supermarket ones and color up really nice with a rich, sweet flavor and good crunch.
The goal with the citrus is different for each citrus. Limes are very tender. They can't hack freezing weather, so I think they'd stay in from T'giving to St. Pat's day. Kumquats need heat to ripen, but the guy in my hood leaves them out here in PDX and has no problems ripening. Meyer lemons when mature can tolerate somewhere around 24, which happens extremely rarely here. Lemons don't need heat to ripen (sour), so they can be out until REAL cold comes in, hence container for necessary move. Kumquats down to 18 or so, so likely need to bring them in a garage for 2 weeks for the whole winter. That's the plan. Put them on Flying Dragon (they usually come that way when you buy them) so that you could bring them in if you need to and they'll be small enough for a container. We'll see how the plan actually works the closer I get to it.
John S
I have two citrus trees (dwarf) in containers and bring the contianers in when temps drop to 27?F. Just today I watched the snow melt off the lemons. The are grafted to P. trifoliate (flying dragon) rootstock.
I planted about 400 P. trifoliate seeds in November 2006 and they are just starting germinate(Feb. 28, 2007). I thought I would have them ready for the scion exchange March 10 but no.
Ted
Hello from NE Portland, Oregon. I have a Meyer Lemon that I maintain in a large tub on the patio. In the winter I lift it up onto a mesh bottomed garden cart. When the temp goes below 30 degrees at night I pull it into the garage, then bring it out again during the over 30 degree days. Bumber crops of fruit producing wonderful lemon pies.
Will
Idyllwild
jafar
Marsha H
Viron
John S
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