Overwintering Satsuki Azaleas Indoors

[sparklemotion]

I live in Minnesota, zone 4. I have been trying to only own trees that are tropical/sub-tropical (room temperature under lights ok for winter) and trees that are MN hardy (outdoors with reasonable protection ok for winter). But mistakes were made.

At the recent club auction there was a a sweet little satsuki that has been neglected (previous owner passed away, new owner wasn't that interested in maintaining refined trees) and I thought would make a nice project. I would have stuck to my guns except that I like azaleas in general and, most importantly: the label said to overwinter the tree indoors.

I'm not one to trust a label from a motivated seller, so after I got home I started doing some research and I wonder if I've been lead astray. Can azaleas really do well indoors (under lights, maybe a tent to up humidity) over the winter months long term? I know there are species that can maybe skip a winter here or there, but give them a couple-or-three years without dormancy and they'll poop out. And I worry that this tree might be near poopage.

Based on what I have read this thread and this thread, and this Bonsai4Me page, I understand that I need to move to Texas and leave the tree outside year-round, or build a greenhouse and keep it at 50F all winter. Then again, Dallas Bonsai says "Indoors, offer the plant a cool, sunny window."

Since I'm not going to move and I'm not in a position to add outbuildings, here are my options for the tree this winter:

1. Indoors, moderate artificial light (positioned under grow light to get about 300-350 μmol/m2/s, 16h per day), in a "cool" basement that's usually around 60F (but goes up to 70F for a few hours a week). (preferred)
2. Indoors, south-facing window 68-72F
3. Cold frame - 38F, no light
4. Cold frame - 38F, artificial light (moderate 300 μmol/m2/s to bright 600 μmol/m2/s, hours per day negotiable*).

*I wasn't planning on lighting the cold frame but I *could* so I could give the satsuki prime positioning and set the schedule as appropriate.

Which of 1-4 would this tree like most?

 

[davetree]

I live in the same zone as you. I have satzuki azaleas that I keep outside from April to November and then winter with no light in an attached garage. Temp is about 25-40 depending on outside temps. It is important to keep them from drying out.

 

[Cadillactaste]

I keep my satsuki' in a cold greenhouse temps around 30F no artificial lights added until spring. Then lights come on when I see things starting to wake up. I water about once a week. If I find snow on the ground I top pots with it if the pots are frozen. If no snow I check back sooner to see if they will accept water. But for the most part water weekly for dormant trees.

 

[jimib]

I'm glad I saw this. I had the same question. I'm in zone 6 ( Columbus Ohio) ad have an unheated greenhouse or attached garage as options. I may just keep it in the greenhouse now.

 

[Cadillactaste]

I'm glad I saw this. I had the same question. I'm in zone 6 ( Columbus Ohio) ad have an unheated greenhouse or attached garage as options. I may just keep it in the greenhouse now.

I have a heated greenhouse at 30F... I wish to also mention...a warm winter one might need to open a door or window. A thermometer with an alarm to alert to such warm days when temps are rising is an important item to add for success.

 

[jimib]

I have a roof vent and shade cloth... it's in direct sun most of the day. I do have a thermometer with a Bluetooth app to monitor the temps. Thanks for the valuable info, and sorry if I hijacked a thread!

 

[Cadillactaste]

I have a roof vent and shade cloth... it's in direct sun most of the day. I do have a thermometer with a Bluetooth app to monitor the temps. Thanks for the valuable info, and sorry if I hijacked a thread!

Looking at one similar...but really want an alarm to go off if things go array in the cold winter nights. So looking at one that has an app for wifi monitoring with still an alarm is where I am at. Chugging through their options on alarm sounding systems.

 

[butlern]

check out Sensor Push.

http://www.sensorpush.com

alerts your phone when pre-set temp thresholds are exceeded. Mine alerts me when temp drops below 34 F... but you can customize that to make sure it alerts you when temp drops below any temp you think is too cold for your trees. There is also an upper temp setting to alert you when it gets too warm.

 

[jimib]

The alarm on my phone goes off at preset temps I can customize. But I’m gonna look into that sensorpush one. Mine is actually for a smoker..

 

[rockm]

This can depend on the variety of satsuki. There are colder hardy varieties and those that can't take a long winter outdoors. I learned this from some professional bonsai nursery owners who overwinter a big jaw dropping collection of huge imported satsukis. The owner goes to Japan every year to a satsuki bonsai master and comes back with awesome trees. Apparently, the guy had some issues with dead trees over the winter--until the master in Japan asked about what kind of winter he had. The master told the guy that the reason he was losing trees was they were the "wrong kind" for the climate. He then steered him to the colder hardy varieties. He hasn't had an issue since.

I have overwintered a "Shiro Ebisu" satsuki outdoors for five years mulched into an overwintering bed with my other cold hardy bonsai. have had many days well below 25 F. It does fine. However, I know a few people around this area who have tried the same and had problems--different varieties. I have no expertise in satsuki cultivars, I just got lucky

If the seller recommended keeping this one indoors, it's probably a more tender variety (if you can, find out what kind of satsuki it is). That said, I would be very cautious about keeping this inside without air circulation and a lot of light.

.

 

[butlern]

captures all the data and stores it... you can track temperatures (and humidity) from multiple sensors for years. Pretty cool.

The only downside is the sensors are not specifically designed to be exposed directly to the weather (rain/snow), but mine just sit on shelves in a garage (in which I over-winter), or the kitchen window sill where they are protected from direct rain fall and sun shine.

 

[Cadillactaste]

The alarm on my phone goes off at preset temps I can customize. But I’m gonna look into that sensorpush one. Mine is actually for a smoker..

I'm wanting a base monitor alarm...for when wifi during ice storms are out. But it's a good system it seems you have. Ambient Weather was what I was looking at. But will check that brand as well. Thanks! My system of five years was having glitches coming into spring.

 

[Leo in N E Illinois]

In my reading, and from conversations with Bruce W, @Shima , I know Satsuki are successfully flowered in Hawaii. One of the addendum chapters in Callahan's Satsuki book is an article by someone else on bloom induction in Satsuki. Unlike groups like Malus, Satsuki have relatively short or mild chill requirements. I don't remember specific numbers but I do recall that if you winter them at 40 F at night (4 C) it takes relatively few weeks to satisfy winter chill requirements. (vaguely remember maybe 8 weeks) If you winter them at 55 F at night it takes longer, something like twice as long, but that winter chill requirement will be met. (I vaguely remember something like 12 or 16 weeks). I could be wrong on the numbers, someone with the Callahan book please correct me if I got it wrong.

So how do I winter mine? I'm in the far northern suburbs of Chicago.
Done it two ways, I have put them in a dark, below ground well house. It hovers at soil temp at 5 feet below ground, right around 32 to 40 F (0 to 4 C) - it is totally dark, and I've never had an issue with them having set backs because of the dark. I am lucky, this would only work if it is below 40 F. Unlike the Japanese maples & pomegranate, I have no problem with them sprouting early when soil temperature creeps up over 40 F the last week or two before our average last frost date. This is a great way to winter Satsuki. I have also wintered the same way ''Florists azalea'' the ones bred for big flowers and easy bloom induction in flower pots for the floral trade. They usually seem fine with this method.

The second way I have wintered them is by putting them into my orchid under lights set up. This is warmer, with night temperatures usually above 55 F but below 65 F. In this set up I run into 2 problems. My orchids average wanting water every 5 to 7 days, under lights, the azalea will want water every second or third day. Long holiday weekends have caused a few losses due to drying out. I have nearly 1000 orchids under lights, so the watering schedule is driven by the orchids, the bonsai are not ''in charge''. This eventually caused me to try the well house, and I like the the results better in terms of convenience.

I do leave my Satsuki outside until after a few light frosts. Depending on my energy level, I either just chuck them in the well house a bit early, before end of November or do the ''in and out dance'' and bring them in to avoid the occasional hard freeze, then back outside for another week or two of just barely above freezing nights. Doing the ''in and out dance'', I can mostly keep them outdoors into December some years. This can mean that winter chill requirement is satisfied pretty early. I have had 'Asahi-no-izumi', bloom unusually early, March instead of late June, but when put back outdoors it seems to settle back into its normal schedule. Others like 'Waka Ebisu' and 'Shiro Ebisu' seem to not be as strongly disrupted, and bloomed only two or three weeks early when wintered with the orchids. So under lights wintering works if you can stay on top of the watering.

My florists azalea when wintered under lights seem to do slightly better, like adding another season of growth, than when wintered in the dark well house. Florist's azalea tend to bloom really early, around middle of February, which can be nice. Azalea growth under lights is surprisingly good. I have them under either a 400 watt high pressure sodium lamp or under a 8 lamp, 48 inch long, T5 High Output Fluorescent Light fixture. This is not bright enough for pines, marginally okay for Japanese maples that break dormancy too early, passable for pomegranate, though full sun outdoors I get better growth on pomegranate. So the fact that outdoors azalea like part shade pays off under lights.

However due to the inconvenience of having to water more often than the orchids require, I do try to winter all my azalea in the unheated, dark, underground well house.

So I think you can get away with wintering an azalea on the windowsill or under lights, but you do have to stay on top of watering.

 

[M. Frary]

Whatever you do,if you live in zone 4 dont leave one outside in winter.
Mellow Mullet sent me one and it didnt take to winter here very well. Not at all. Probably didnt make it until Christmas.

 

[Kendo]

If Inari not bringing sun dragon to you then best example is to making best bed possible. Thank you Hai Keeping low with the cover is preferable. Hai Bonsai Craftsman Leo in NE Illinois is having nice location under home. Primary concern would be keep condition stable. Hai Using the Hoshikusa with plastic is acceptable. Hai Same as Bonsai Craftsman Leo in NE Illinois keeping the water variable satisfactory is of large consideration. Hai Thank you for discussion.

 

[JudyB]

This can depend on the variety of satsuki. There are colder hardy varieties and those that can't take a long winter outdoors. I learned this from some professional bonsai nursery owners who overwinter a big jaw dropping collection of huge imported satsukis. The owner goes to Japan every year to a satsuki bonsai master and comes back with awesome trees. Apparently, the guy had some issues with dead trees over the winter--until the master in Japan asked about what kind of winter he had. The master told the guy that the reason he was losing trees was they were the "wrong kind" for the climate. He then steered him to the colder hardy varieties. He hasn't had an issue since.

I have overwintered a "Shiro Ebisu" satsuki outdoors for five years mulched into an overwintering bed with my other cold hardy bonsai. have had many days well below 25 F. It does fine. However, I know a few people around this area who have tried the same and had problems--different varieties. I have no expertise in satsuki cultivars, I just got lucky

If the seller recommended keeping this one indoors, it's probably a more tender variety (if you can, find out what kind of satsuki it is). That said, I would be very cautious about keeping this inside without air circulation and a lot of light.

.

Is there anyone who knows of a guide that determines which are the cold hardy ones and which ones are not? I'd be interested to know!