Growing citrus in a well

The house I moved into last year used to have a brick well. The owners in the 70's decided to break it up and kept the top half as a planter. I'm thinking since bricks hold heat and it receives a good amount of sun the I might be able to get away with growing a satsuma orange in there. I'm in Portland so it does freeze here but not often. I'm thinking maybe I can cover it in plastic if it gets cold. Sound like a good idea or is this crazy?

It is possible. The design sounds good, but the inside diameter of the 'container' seems a little small. I can't tell exactly from the picture, but it appears to be around 2 feet in diameter. If you keep the tree small then it could work, though at that small of a size it would be easy to keep in a movable container.

Ice doesn't seem to instantly kill any of the citrus trees around here. They get hard freezes inland pretty often in late winter, and even the beach gets an occasional hard freeze every couple of years. We do have the citrus greening disease killing off our trees, and a hard freeze will damage fruit, but the tree itself doesn't seem to have cold problems since the roots and main branches generally don't get that cold. When it warms back into the 60's and the sun beaming down can feel more like the 80's then the tree only experiences a few hours of a hard freeze and many times it isn't multiple days in a row. Getting your micro climate to create these conditions should increase the chances of success. Covering it during really bad or long freezes will be important. I have used a small rocket stove to heat bricks which I threw under a canvas tarp to protect some sensitive plants in the past.

Given the citrus greening disaster going on here I have little interest in fighting a losing battle trying to grow citrus, but I have learned a couple things. Many citrus trees seem to have their fruit mature in late fall to early winter. Having an early frost could destroy those fruit before maturity. Something that bears more often or at a different time of year could bring better yields. Also something smaller that doesn't hang on the tree as long could be beneficial. Something like a Key Lime could be another option. They grow true to seed and the leaves also taste like a strong lime. Other citrus leaves I have encountered smell terrible enough that I would not try tasting them, but the Key Lime leaves can be used to cook with. I made some rice once that I added a few leaves to and it came out rather well. This was right before I found out about the citrus greening disease that ended up killing my limes.

In any case, as long as you protect the fruit then you could get a good yield from the tree. The root system will probably be substantial if it isn't vigorously pruned. I could easily see a tree planted inside that well busting the bricks apart if left to grow on its own. If you get anywhere growing the tree then it would be great to see pics!

I've lived in the NW and now live in So. Cal., so I'm pretty familiar with the weather of both. Citrus likes warm dry nights. The six months of cool wet weather in the NW would be a greater concern, in my opinion, than the occasional frost.

The fruit grows through the summer, but generally isn't ripe until November/December . . . some trees don't get sweet until January. I don't know think it would be sunny and the dry enough to sweeten the fruit. Right now in So. Cal, even though it's winter, we have full sun, 9 days out of 10. My Valencia tree is only now ripe enough to juice those oranges, and it's 3 months after New Years. So while the thermal mass of that bunch of bricks would be helpful in the summer, they'll also be a cold sink all winter as well, staying cool well into the heart of your already short winter months.

For myself, if I lived in your neck of the woods, I'd plant Rainer Cherries and hazel nuts.

But heck, a small tree is only $30. Go for it and see what happens. If Sepp can do it, so can you.

Wow! Thanks for the excellent response. Yeah I agree the tree could probably bust the bricks if it got too large. I plan on keeping it pretty small so I can cover it as needed. I haven't measured the inside diameter but I'd guess that you're close. I'll post some pictures if I go forward with it. I read an article about fruit walls recently and that got me thinking about this

Yeah good point Marco. I wasn't thinking about the never ending wetness in the winter. I do have a few hazels. I'm planning on expanding them into a living fence. Oregon is known for hazelnuts after all

Did you decide to go forward with this?

A fellow named Bob Duncan on Vancouver Island specialized in growing citrus. The long ripening time is an issue, and I recall that his oranges were in a hoop house which he could add heat to if it was atypically cold. For many of his trees, he wrapped them in old incandescent Christmas tree lights, as that was enough to keep them safe!

A few years back we had for us, very cold weather. Many people lost their marginal plants. I truly pays to have a back-up plan ready to go.

Seconded, Im very curious about thermal mass and citrus.  Especially a vertical function which seems like it might make air flow warmer. Growing off season crops becoming important with climate change as well.  

What might work better is to grow some sort of zone 9-or-up tree which ripens in summer or early autumn, that way it will be done fruiting before first frost which usually occurs in Nov. around here (although last year my house didn't get a gentle freeze until late Dec. haha).  But yeah, the bricks could help for sunny winter days to get the tree through and the covering could help on the really rainy or really cold nights.  And that the tree could survive winter, but thrive in summer.