I dont think that brief cold matters, plants went into shock with your change in conditions indoors. No pics of soil in pots. how were they being kept?

I would keep them indoors next to a bright window.

I hate those high grafts, really makes it hard to keep a tree indoors as a practical matter unless you have high ceilings/a high greenhouse etc. Nice big specimens though.

BK not sure the previous conditions when I picked them up they were brought out to my van. It's in the typical nursery mix that all store bought citrus come in. Here's a pic.

Denise, a bright window is not an option. So you believe they need more light to recover than heat? My options are either or not both. I can offer them sun up to sundown bright but cold or inside hot, dry and dark. My wife will not allow me to make another plant area inside with lights and humidifier.

Cold and bright or hot and dark are both recipes for citrus collapse. The reason is that temperatures increase root activity and light increases leaf activity. Without the two in relative balance the tree will either overheat its leaves and drop them or it will run out of sugars and die.

Denise I've agreed to her terms long ago she has her limits. Every room has plants near the windows in addition to the garage and parts of the basement. I might have to sacrifice my biggest banana to get these guys the combination they. What is high temperature in your sunroom, actually the real question would be what is the overnight temps in your sunroom?

Oh my goodness. I can now understand why your wife is upset with all the plants. lol. I have not been checking the temps. The sunroom was originally just a screened in porch and my husband enclosed it with glass and added additional ducting so whatever heat reaches it just keeps the room from freezing. The lowest I have had so far was 44* that I can remember. Sunday and Monday will be 26 and 27 outside. If there is a windchill may be as low as 19*. So we'll see how low we can go. lol. While spraying my trees outside today, I found another tree with new growth. I truly believe with a good acclimation program, citrus trees can adapt. After all the sun changes position with seasonal changes.

OK sounds good

The bark will likely not be damaged in 3 minutes.

Steve

Do you know what kind of Orange trees these are? Depending on the variety they may tolerate night time temperature drops down to 25 degrees or so. I grow all of my citrus in ground in Louisiana, so can't help much with the indoor growing advice. I can tell you that I have a Cara Cara navel orange that was planted in early 2016, last January it survived a pair of nights at 12F and 13F night with daytime high in the upper 20's between (50+ year low), with only being draped in a string old style incandescent christmas lights, and covered with old lightweight table cloth / blanket. Though it did suffer some die back and about 50-60% leaf loss.

Steve you are correct the barks are not damaged but the leaves are shot. I will give them full light as Denise suggested and they will recover. I will also wait for April-ish to trim back.

Ike they are Valencia.

I would suggest later than April before doing any trimming

Got it Ike.

Denise what was the day and night temps in your sunroom this past week and did you supplement heat?

I have been keeping a log of the temps; inside and outside. For the past week, we have been having outside lows from 25*- 29*. This morning the low was 29* outside and the temp in the sunroom was 52*. I temped the 20" pots next to the window and was around 49* and the same size pot on the opposite side of the room was in the 50* range as well. As I said, the room is poorly heated compared to the rest of the house, but my husband did add extra insulation in the attic so that helps. I have been bumping up the temps in the house sporadically because I get cold easily. With there being no way of air being removed from the room, that would account for decent temps. We only go into the room to let the dog out. The plants closest to the window are forming flower buds. The temps should be mild this weekend so I am going to take them outside to inspect for pests and possible watering. I am still experiencing some leaf dropping, but not enough to worry about.

Edit: I have only been keeping track of the temps of the morning hours because those are the ones that concern me most. Our average temps outside for this time of year usually don't go lower than mid 40's so I don't worry about them. The forecast for next week is suppose to be in the 70's.

Wonderful. my sunroof is not that warm lol. My outside temp last night was 3° and in there was 30° but this year I've spoiled them a bit I got most wrapped in heat mats. I will send a pic in a few after I get the kids off to school.

heat mats and foil

nice and bright but cold