The Washy protection 'top' would be closed on very cold days or just prior to precipitation events. The Christmas lights were on most of the winter unless temps were above freezing. Snow on top is fine. Snow is a great insulator.

ok so I have buried heater cables , I dont know that it helps that much. I do it to jump start on the spring, I would go with many layers, start with frost cloth...............plastic, blanket and maybe ugly blue tarp
use a larger 30 gallon bucket, cover it and use a 10 dollar fish heater
(I have coral tanks also lol)

you can get decent remote thermometer on line,
remember they can get cold just not below 20 or s..............

I didnt heat the roots of my kumquat and satsuma and they are fine, in fact starting to flower,
I have about 14 outside in the ground
I cover around nov 1 depending on if I am waiting for fruit and uncover around Mid march, depending on the amount of work u want to do

after 5 or so years they are around 4 feet tall

this question maybe others can answer, in order to keep the ht to a minimuim should he or I put the plant in a mini well, say 1 foot down.................

sorry for the late respose, if u want pm me ur cell phone number and I can discuss this with u over the phone

I will read the thread a bit more now

ps if u do this for 1 tree it is almost free to do it for 4!

also the fruit on my meyer , satsuma and thomasville citrangequat matrure in the dark absolutely no problem...............we just picked the last thomasveile from last summer!

Rodents did chew the base of a kumquat tree one year............

I thought about the circulating water also, but (since I have aquariums) I think it is not needed, IMO...................keep it simple as things will go wrong (like the freeking wind blowing the blanket off when you are away)

Keep your how cold did it get there last year?

honestly a 30 gallon bucket of water, fish heater, plastic, bed sheet, and tarp and u are set, cover the plastic in the fall with dirt so when it freezes it sectures the structure, use PVC to make a dome.............

I need to write a book lol

oo and I dont mulch......

Hasn't everyone heard of the automatic vent opener-vent closer used for cold frames?
They are powered by a piston with a cylider full of wax. Wax expands as it thaws the oposite of water. And different kinds of wax have different melting points. So you can get these openers preset for different temperatures.
They last a long time, so it has been about 15 years since I shopped for and bought two of them. They, at least mine, were rated to lift 50 pounds each. That is a good sized vent, unless there is a load of snow on the vent.
A neighbor bought 3 for his greenhouse the same time I did. They are still doing fine.
Nothing wrong with manual openning and closing vents, if that is what you want. But if you are gone, or have the flue, these automatic vents are great.
I thought them quite expencive when buying

When posting, it cut off the last line I wrote.
When I bought mine, I thought they were expensive. Now I think it was money very well spent.