Your citrus should be ok at 51. If you leave them outside overnight, you are mimicking spring temps. Cool nights and warm days. This should encourage blossoms to form. If I knew the possibility of deer eating my trees, I would definitely bring them inside and take them out whenever I could. Natural sun from 12-6 or whatever is still better than being inside or eaten by deer.

I would leave them out. What types do you have? Deer are especially drawn to Meyer lemons and will often leave others untouched. So long as night temps stay above 40F, I would leave them out.

When I posted this, I was curious about the weather, but now I'm paranoid about the deer. I have a Meyer, ST, Satsuma, Tango, NZL, Pink Lemon, Key Lime, Persian Lime. The deer have never touched my citrus...yet; they eat everything else. I'm sure a day will come come they do go for it, but I've been lucky so far. During the summer, I tuck the pots up next to the house at night, behind some bushes. But this time of year everything is dead and there's no cover.

As much as I would love to leave them out, I'm would be devastated if they deer 'sampled' them. I guess I have to sacrifice the morning light for trees that are not eaten. I really need a greenhouse and a way to keep the deer away. They have no fear here. Last summer I lived in constant anxiety and would wake up in the middle of the night because I heard them tramping around the garden. I'd run over to the window and bang on it and yell at them. Everyone thinks I'm crazy, they are probably right.

Deer...squirrels...just a matter of time. Maybe some luck.

Deer and goats absolutely love Meyer lemons; maybe they just have not discovered them yet.

we have a million deer "runnin' loose in our subdivision....i have seen over 50 in my yard at a time (during a flood) while they ate everything else except salvia and herbs in my yard, they have never munched on a citrus tree..... they have torn the main trunk of a 3 year old grapefruit tree and some bald cypress tree during rut (with their horns) but never munched on them we have white tail deer don't know if they makes a difference or not..

Doesn't make a difference; the only difference is they have not yet discovered the Meyers. Once they discover them (not native, of course), there will be nothing that will keep them away.

I will leave my Meiwa trees outside as long as the forecast doesn't call for below 35F My valentine pomelo will be brought in for temperatures below 45F.

Steve