Good! That gives me hope. I will bring them in as soon as i get home. When i left home the leaves still looked perky.

Your trees should be brought indoors when night temps start dropping below 55-60*. They might survive the chill, but they definitely won't like it. Your tree is unable to efficiently carry on photosynthesis when night lows are below 60*, and the plant doesn't recover that ability just because the temp might happen to rise above 55-60* during the day after a cool night. So essentially, you put your tree in a position of using its energy reserves to grow and keep its systems orderly when you subject it to chill. That means that when you finally do bring the plant indoors, its energy reserves are much lower than they might have been had the plant been brought in before it was subjected to low temps. No matter what the plant looks like, it isn't doing fine after being subjected to a prolonged period of chill.

Al

They seem to be fine but we will see how it plays out.

@tapla thanks for that specific information on the 60* I had posted looking for details like this a month ago (concerned of my FLF trees as well here in Houston) but never got much info. My next question I never got an answer for.... do we then continue taking the trees back out for the few hours of direct sun its used to when it warms up a few days later and then back in again when the temp drops again 1-2 weeks later and continue that cycle for the next 2 months of our Houston Texas "winter" or once we bring it in is it better to just let it acclimate and stay inside till it can go out and hopefully stay out? Ive been doing the in and out a few weeks so far plant "appears" fine but hard to tell if its stressing it.

The tree is less likely to lose foliage if you move it in and out as temps allow, but it's a pitb to stick to that plan, so you decide. The tree will but on a little more weight and be stronger o/a if it gets its daily sun bathing session, too, but since your winters are short, it wouldn't be something you'd notice much, even if you had a basis for comparison (like an imaginary tree equal to yours in every way except for the fact you over-wintered it indoors entirely).

Al

The first thing to go when potted stock experiences cold damage is the youngest roots on the outside of the root mass, followed by the older roots farther back inside. The top is the most cold tolerant part of a plant - to assess the extent of cold damage the first place to look is the roots, and not the top.

As mentioned tropical house plants should be brought inside in autumn while indoor and outdoor temperatures are still comparatively similar. In addition since light levels are often so different between ordinary indoor living spaces and the world outside there can often be problems with burning of the leaves when house plants go outside. And new growth made during a summer outside may not be well adjusted to lower indoor light levels, when plants come back inside during autumn. Weeping Fig for instance is a commonly used one that is quite apt to shed leaves excessively when moved from one aspect to another. Also bugs etc. may come back in with specimens that have been out where these are. For such reasons it may actually be better to keep house plants inside throughout the year.

When houseplants are the topic and we remove blooms/fruit from the scope of discussion, leaves are the first organs that experience cold damage as temperatures fall - especially if they fall rapidly (physical cold damage/injury can occur at temps as high as 50* if the drop from higher temps was rapid); or, if we consider the inability to carry on photosynthesis at low temps damage; and a good case can be made that it IS damage because it forces the plant to switch to energy reserves, rather than using current photosynthate in order to grow and keep its systems orderly. That means the leaves are the first place to look for cold damage.

Roots of pots resting on the ground are benefited by geo-thermal heat rising from the ground AND from warmth created by the composting process occuring in the organic fraction of soils. From this, we can easily envision that root/soil temperatures of pots on the ground will be significantly warmer than air temperatures under conditions of falling temps, and at least slightly warmer than air temps when pots are isolated from an extraneous heat source, like geothermal heat or heat making its way through the walls of a heated building.

You are correct, however, in thinking that the hardiest part of a temperate deciduous plant that is in a predictive dormancy is the dormant 'top' (trunk and branches), which would be devoid of leaves. But, before we would arrive at temps where we would be thinking about root hardiness, the leaves of temperate deciduous plants would almost certainly have decided to abscise, based primarily on shorter day length (actually, it's the longer dark period that determines that response) and decreasing temps.

Al