When to put citrus outside z5-6

Good morning!
I'm trying to figure out when I can put my orange, grapefruit and lemon trees outside for the spring & summer....
Today is lovely, already in the 50-60s, but it's not going to stay that way. What temps/conditions can citrus tolerate? Would they be better in the garage?
Thanks!
Deb

Deb

“The rule of thumb for (mature oranges in ground) trees is that you won’t see damage until you have 28 degree weather for up to six hours.” Navel oranges are considered to be slightly more cold hardy than round oranges, which are only slightly more cold hardy than grapefruit. Lemons and limes are considered among the least cold hardy. For Container citrus I would keep them above freezing and they will do fine. Citrus need to be stressed to produce more fruit. If you keep them too happy by artificially keeping them warm, they will put on more foliage and less fruit. In the tropics stress is caused from drought and here it is cold that stimulates stress, which triggers more fruiting.
Another thing to avoid when moving citrus is sudden changes in light intensity. They really don’t respond well to this. Hope this helps you.
Oldude

Deb, my Navel orange and Lisbon lemon have been out for 10 days now, and I am in Canada. We have had temps to +1C or32f and I don't panic. I put my citrus out early so they think they are getting a Winter... I also leave them out as long as I dare in the Fall to give them another Winter. By doing this I get 2 flushes of spring flowers. There is more fruit set outside, probably because of the insects, but the smell inside in November is lovely too. Robb

Hi Robb and Olddude -
thank you for the advice. I've put the citrus outside for now. Our temps are varying between 40F to 90F(!) Spring in New England is interesting to say the least. How big are your plants? I'm really a novice, I've just started growing citrus since they seem to like my sunny basement in winter, so I really appreciate any advice you can give. Besides there is the immensely good fragrance of the blossoms....

Do the trees like to be a little root bound or is it a good idea to keep upping the pot size? How frequently do you fertilize? I have a citrus/tropical granular fertilizer that I'd like to use.
I've got one branch on the navel orange that is turning black from the end of the branch moving in. I have no idea what it is. I can't find bugs or scale or anything like that. Any clue?
Many thanks!
and Robb, I like your name "zoneimpaired" - it applies to a lot of us, I think!

Hello Tamberlin,
My lemon is about 6ft tall... I have kept it pruned to that size for about 10 years now. The orange has reached 5ft. The lemon is in a 10 gallon pot that I top dress yearly with composted sheep manure when I put it outside. I scrape the top 2 inches of soil off and replace it with the manure. The orange is in a 5 gallon pot. I am sure they are rootbound by now but it is hard enough to keep them in bounds... I don't want them to be too happy. This year I had a terrible attack of scale; on trees this size the Q-tip and alcohol doesn't work. When I could get them outside I sprayed with horticultural oil. I will try to find a systemic but they are banned in this province. I have used cygon to great effect in the past , and I am very careful. Robb