I have a few marginal plants (mangos, cherimoyas, lychee, small avocados) I'll likely need to protect from freezing during several nights this winter. I made a stand for them on casters so they can be easily rolled across the patio and under the eaves, against a window. I put in a few screws to quickly anchor the grommets of a tarp, and now I can cover everything in just a couple of minutes. Our inefficient, single-pane casement windows will undoubtedly radiate enough heat to the great outdoors to keep the plants well above freezing, and who knows--maybe the tarp will even reduce drafts in the house! I did a dry run this morning to make sure there won't be any problems some cold evening when I'm in a hurry:

view from outside:


from inside the tarp:
 

looking through the window:
 

You can add a 25 or 50 watt light bulb and get a surprising amount of heat. There might be a problem is the plants touch the plastic- those parts might be damaged - but if it is only a few leaves, probably no biggie.

Very nice idea!  And the lightbulb suggestion would be simple to add.

Thanks--the lightbulb is a good idea.

Tucson Ken, I live in So Cal & winter is almost unknown here. You did a great job protecting your trees. Also, you may be able to answer my question...i have a few dwarf fruit trees in my tiny backyard. About one month ago my gardener chopped off the root of my in ground dwarf Mexicola Avocado and it totally drooped & i think its dead. I trimmed off leaves & took off ALL of the avocados that were hanging. I am trying to save it by giving it a lot of worm castings & tlc...i know avocados are strong but im not sure this little guy will live. Any advice is appreciated,

Nice setup! I have been resorting to frost cloths + C9 Christmas lights for my mangoes, avocados, etc. My white sapote, jaboticaba and lychee will eventually be able to take the cold here, but they are still young so I am protecting them too this winter.

Smyfigs, unfortunately I'm no authority on avocados, but if you've still got green leaves or branches I'd guess your chances for recovery are good. You might want to rig some temporary shade, and if the foliage is still wilting maybe do some pruning to try to balance the amount of moisture being lost through the leaves with the amount being taken up by the remaining roots. With a young avocado graft I sometimes keep it tented in a plastic bag to keep the humidity high until the vascular connection between the rootstock and scion is strong enough to keep the leaves supplied with enough water--maybe you could make some kind of tent around your tree if it seems necessary, but take care not to cook it in direct sunshine. Good luck!

Starch--I sent you a PM.