Overwintering Tridents in Zone 7B (5 to 10 °F)

[groffralph]

Hello-
I Started a Deciduous Collecting this past Spring approx. 15 Trident Maples, a Bald Cypress, and a Dawn Redwood. These Trees Range in age from 2-7 years old. They are all potted in Bonsai Pots and Potting Planters. They spent the spring and summer in the garden and on benches. I Built a 6x8 unheated My Cedar Green house w/an exhaust fan and automatic thermostat/humidistat in August.

Can I safely Overwinter these Trees in my greenhouse in Maryland zone 7B. Any information/recommendations would be greatly appreciated.

Cheers,
RG

 

[rockm]

Hello-
I Started a Deciduous Collecting this past Spring approx. 15 Trident Maples, a Bald Cypress, and a Dawn Redwood. These Trees Range in age from 2-7 years old. They are all potted in Bonsai Pots and Potting Planters. They spent the spring and summer in the garden and on benches. I Built a 6x8 unheated My Cedar Green house w/an exhaust fan and automatic thermostat/humidistat in August.

Can I safely Overwinter these Trees in my greenhouse in Maryland zone 7B. Any information/recommendations would be greatly appreciated.

Cheers,
RG

You will NOT need a greenhouse for ANY of those trees. If fact you will probably do more harm than good using it. It will heat up in the winter and keep things way too warm--even with the thermo and fan. It's too small to be able to control the heat effectively. You will also probably have early bud break on all of those trees in such a structure (like leafing out in early February). If that happens, you will have to bring all of the trees that have open buds into the house until the end of March, or even mid-April until the danger of frost and freezing has past.

Don't make the mistake of thinking trees have to be kept warm to make it through the winter. They don't. They have to be kept as cold as possible for as long as possible. They are not animals, they are plants. The "heat" required for them to survive is not above freezing. It's probably 20 F. or so... Warmer than 35 and they will break dormancy early.

I've kept ALL of the species you have in Va. zone 7 for the last 25 years outside in garden beds with pots buried in a foot of pine mulch. Haven't had an issue.

 

[groffralph]

Rockm- Thanks for the input, greatly appreciated.

RG

 

[dbonsaiw]

Rockm is spot on (again). I used a similar type of greenhouse last winter and it wasn't really needed. You will not be able to control the temperature (it will freeze and thaw regardless) in that setup and you don't need to as the trees want the cold. The only benefit I found from these types of glorified tents is protection from freezing winds. I will be burying my pots either directly into the ground or in a mulch pile.

 

[W3rk]

Hello-
I Started a Deciduous Collecting this past Spring approx. 15 Trident Maples, a Bald Cypress, and a Dawn Redwood. These Trees Range in age from 2-7 years old. They are all potted in Bonsai Pots and Potting Planters. They spent the spring and summer in the garden and on benches. I Built a 6x8 unheated My Cedar Green house w/an exhaust fan and automatic thermostat/humidistat in August.

Can I safely Overwinter these Trees in my greenhouse in Maryland zone 7B. Any information/recommendations would be greatly appreciated.

Cheers,
RG

I'll add one other thing. I'm in the same area as you and RockM (Metro DC). Our winters are generally pretty mild. My main concern (I overwinter most of my trees outside mulched in beds like RockM mentioned) is water. We have very wet winters and easily get more rain the snow it seems. A good solid freeze would be better. But I've had some limited issues with overly wet roots and some root rot.

 

[Ugo]

Can't you protect the trees with a tarp on top of your winter shelter?
You will have to water the tree during the season but atleast you're able to control watering better.

Here in zone 5b I have not other choice, my winter shelter has a solid roof as too much snow will accumulate on my trees and when melting all the water might drown them so I open the top when needed if its snowing or I shovel snow inside but I cant leave it open all time.

Winterizing outside is fairly easy as long as you keep elements in control...
I perfectly understand your point, a good freeze would be better as for example I can easily keep Akadama outside in winter here as the soil would freeze almost completely and stays like that for months, the tree has low demand in water as its protected from sun and wind.

You might need a different solution but with the same approach.
Too much water.
Cover the trees
Take opportunity to open everything when you get a slightly colder spell and cover everything to keep cold in.
Breaking out from dormancy happens when the temperature rise and there more light hours.
Change that and your tree will continue to sleep!

 

[Paradox]

I'm in 7a. I put mine in a cold frame and only cover it if temperatures are supposed to fall below 30 for an extended period

 

[Dav4]

Last winter, I overwinterd a bunch of tridents, big and small, outside in zone 6a MI, packed together with pots covered in mulch in a protected area of the yard up against the house. It fell below 0 F 6-7 times, coldest being -6. Other than a bit of twiggy die back, they did fine. They had spent the previous 13 years in 7b N. GA where they stayed on the benches for most of the winter, only getting put on the ground when the temps were falling into the mid to lower 20's.

 

[jonfromchicago]

Your trees will be fine in the Cedar Greenhouse you built. Just keep the door or window open during the day so the temperature inside will not rise past 40F.