Some thoughts ahead of the winter

Here is my reply to a comment under the last post:

"Buddy, you're awesome! I live in Nebraska (your neighbor) and I'm so scared to put my baby outside in the ground. She's 4 years old, I grew her from a seed. She's the only one that made it from the seed out of roughly 6-8.

What do you recommend? I'm incredibly attached to this tree so, yeah. Please help me lol"

One thing that you (and me) need to accept is that sequoias in Zone 5 is an indoors plant. It's an indoors plant that we expose to a hostile outdoors environment incompatible with its genetics. I can give you my best advice but the chances are slim for your sequoia to grow outside. Nobody said it was going to be easy though, so it's all good.

It appears that sequoias need to have more or less continuous access to liquid flowing water. They are 100% freeze intolerant for their root system. Any pot that had been frozen, they die. Last winter I had 6 sequoias in 2 gallon pots in an unheated shed. They were placed in a plastic tray with flat bucket heaters under the bottom of each pot. The tray was filled to about one inch depth with water. Water stayed mostly liquid during last winter since it was not a terrible winter like a few years back. However, a few times during the winter the temperature dropped enough to freeze the water completely for a few days in a row. I kept adding water and even placed a continuously blowing space heater directed at the tray. Being in a shed, they were protected from the blowing wind. However, they were not wrapped in any fabric or plastic. I could say that the soil in the pots got frozen out and only roots at the very bottom were exposed to liquid water throughout the winter. It was not enough. All 6 were dead by the following summer.

For the upcoming winter I am planning on protecting the trees with applying anti-desiccant to the needles with fabric and plastic wrapping, same way I did before. However, this time I will continue watering several select sequoias throughout the winter. My temperature sensor experiments from last two years showed that it's not terribly difficult to keep the temperature continuously above freezing at 1 foot depth with application of a thick layer of mulch. What was missing last winter was access to liquid water. I was hoping that enough snow would melt and trickle to the roots, but it appears it was not the case. My new plan is to water wrapped sequoias with excess warm water through a hose stuck in mulch a couple of times a month and especially during cold spells. I believe the trick is to keep feeder roots exposed to water continuously. Tap root alone is not going to do the trick. 

Long term survivability of sequoias in Zone 5 is questionable but one could imagine an engineering solution where water could be delivered under ground through some clever combination of heat pipes and water pipes that would melt the snow from above and deliver flowing water to the roots. Something to ponder about. 

My oldest surviving sequoias are 6 years old now. You would never say they are that old. They survive by being small, bush-like and fitting under a foam cone for winter. One overgrew the largest cone available at Menards but I forced it inside by folding the top. As a result it's still alive but many others that I was wrapping in fabric and plastic are dead. In general those foam cones work very well but by no means a guarantee of success. 

267, 6 years old, under 2 feet

My tallest but not the oldest sequoias are now about 7 foot tall. I have one that's 6'8" and another that's 7'2". 

365, 5 year old, 6'8" 

#365

A blast from the past: #365 in 2017:

#, 7'2"