Satsuki in zone 5/6

[coltranem]

I am curious what are my options for keeping a satsuki azalea in zone 5/6. Right now in the winter most of my trees go in my bulkhead where temps can vary between 20 F and 40 F. My tropicals go under a grow light in the basement. Would either of these option work? My garage is warmer than the bulkhead has one window but will get below freezing once or twice over the winter.

 

[penumbra]

Temperature in your bulkhead sounds fine but illuminate me, what is your bulkhead?

 

[coltranem]

Bullhead is external cement stairs to my basement. It cover by thin metal doors. No light.

 

[sorce]

Light tells em what to do.

No light sounds the only bad.

Sorce

 

[penumbra]

Bullhead is external cement stairs to my basement. It cover by thin metal doors. No light.

Yeah, I think that is a problem. It sounds fine for deciduous plants bu not for azalea. I am not sure what satsuki you have but some are very hearty and you are listed as zone 6A. My azaleas that are in pots will be in a cold frame and I am zone 6. I have some in the ground planted about 30 years ago that have been down to -14 F. I think many azalea bonsai would be fine heeled in for winter as long as they don't freeze dry.

 

[Forsoothe!]

You can open the bulkhead doors on nice spring days and nights over ~35ish (not frosty) and have a nice headstart to the growing season. Just be sure to close it when temps dip below frosty nights, and don't start doing this too early, like during a January or February thaw that occur occasionally. You can start the open/close thing about 4 or 6 weeks before you would ordinarily put them out. You would see the early stages of leafing-out at that time. @sorce is right that the increase in light intensity and photo-period that is spring tells them to accelerate growth that is the natural condition that accompanies the end of dormancy, which is a function of some number of days in dormancy. This spring sunlight is a problem in garages with windows because the "weather" in the garage says "spring", and there is more sunlight, but the new leafs and expanding buds with leaf edges emerging will be acclimated to filtered or indirect sunlight and will be fried if suddenly put out into direct sun. They need to be gradually introduced to direct sun. Other than that, garages are fine, and better than nothing.

 

[penumbra]

Forsoothe offers some excellent advice here.
I also have basement steps that go to a completely subsurface basement. It is all open but I hope that some day I can build a greenhouse over it.

 

[Forsoothe!]

Forsoothe offers some excellent advice here.
I also have basement steps that go to a completely subsurface basement. It is all open but I hope that some day I can build a greenhouse over it.

You can buy a 2" thick 4' x 8' FOAMULAR 250 2 in. x 48 in. x 8 ft. R-10 Scored Squared Edge Insulation Sheathing for $37 at big box that is pretty bulletproof that you can cover that opening and you have a protected vault! Coat it with roofing tar for better weatherproofing. (Check the label. Not diluted with tolulene, acetone, or MEK: Mineral Spirits is OK).

 

[Leo in N E Illinois]

Actually I find Satsuki do just fine in the dark with no light all winter. I use a well house, temps stay between 40 F and 32 F, with a very rare dip to +28 F if the weather is polar vortex for a week or more at a time. Being in the dark is not an issue as long as the storage area stays cold, below 40 F or 4 C. IF the storage area warms up above 40 F or 4 C for any significant length of time then you must add light.

Satsuki are all over the map as to winter hardiness, because the genetic make up of Satsuki hybrids is so widely varied. Some Satsuki hybrids have hardy species mixed in, and can easily take zone 6b or even 6a winters in the ground. American hybrid azaleas, there are some that are hardy in zones 5 and even 4, and these hybrids include some Satsuki in their backgrounds.

There are Satsuki hybrids, bred in particular for the potted plant floral industry, that have warm blooded near tropical azaleas in their background, and these are only hardy to a light frost at best. The island of Kyushu, where many Satsuki originated in Japan never gets much colder than Memphis or Atlanta, a very mild climate.

So unless I read a description of a particular cultivar that documents its cold hardiness, I assume most Satsuki are hardy only to about 28 F. And my dark all winter well house seems to be an excellent place to winter my azaleas.

 

[coltranem]

I ended up picking one up. Just a Lowes special. Trunk was 0.5 inch. The variety was Autumn Moon (says it survives zone 7). I am going to try the bulkhead and see how it does.

Thanks for the discussion.

 

[PABonsai]

.

 

[shinmai]

When evaluating the cold-hardiness of any tree, it is imperative to remember that the stated tolerance is for a tree in the ground, not in a pot. As a general rule, I add 10 degrees to the upside to have a more conservative idea of how cold something can get.
I have had generally excellent results with a small [6' square] greenhouse, a thermostat, and a space heater and box fan. The exception was last February, when I was traveling and we got temps of 27 below before the wind chill. The friend who was watching the house for me waited too long to call and tell me that the greenhouse was down to 20 degrees, and it probably had been for at least twelve hours. I lost about a dozen small azaleas that were in small pots, presumably because the roots froze. This winter it will be two space heaters. Other than that one instance, the greenhouse has stayed between 35 and 39 degrees pretty consistently.

 

[coltranem]

Finally got some photos. I'd like to eventually remove the thick branch to help with scale.

 

[shinmai]

I agree, it should definitely go. It’s straight-up vertical and sticks out like a sore thumb. Really nice base, though.

 

[Mike Hennigan]

My two Satsuki spent last winter outside on the ground just heeled in with mulch. In a zone 6 microclimate surrounded by zone 5. (Like zone 5 is a half mile away). They did great. Super healthy this season. I’m no Satsuki expert though.

 

[coltranem]

I agree, it should definitely go. It’s straight-up vertical and sticks out like a sore thumb. Really nice base, though.

Yes from the first picture that one is going. The final tree will be shorter than that. The branch I am referring to is at the base (see below). When is the proper time on azaleas to remove that? Also do I flush cut or leave a stub first.

 

[sorce]

My two Satsuki spent last winter outside on the ground just heeled in with mulch. In a zone 6 microclimate surrounded by zone 5. (Like zone 5 is a half mile away). They did great. Super healthy this season. I’m no Satsuki expert though.

Sounds safest and most appropriate.

Sorce