Satsuki azaleas in the ground zone 8+

Anyone successfully grow out Satsuki azaleas in-ground, or even better in zone 8 and above? Were they able to take more sun intensity than they could in pots?

I want to fatten up my Satsukis faster than I could in pots with Kanuma, which I'm already doing now but its going slow.

You should have no problem in zone 8, though afternoon shade always helps.

I'm in 8b too. I have several nurserymen friends here that grow American and Japanese satsuki varieties from the landscape trade. Of course they're in pots, but they are grown in a light, mostly pinebark soil mix with lots of fertilizer and irrigation. They are also grown in fields in all day full sun, the only shade is a passing cloud.

R

That is very good to know. I think I would end up making a smaller raised bed with acidic mix, since my soil is basically dirt mixed with limestone, and try and find an afternoon shade location.

One thing that I didn't mention is that not all satsuki are the same. Some simply can't take the heat, others hate the cold. Find Yvonne's satsuki fall color thread from a couple of weeks ago in the main forum. Do you know which varieties you have?

Hi Discuspro and Russel,
Russel you mentioned in the tread about the satsuki of Yvonne,
Kinsai, Matsu - Nami, Kikoshi as varieties that like a some more cold climate.
Is there somewhere a list to be found on warm or cold needing satsuki?
Sunip

Hi Sunip. No, to my knowledge, there is no list. Maybe Glaucus can help...

Russell Coker, I checked out Yvonne's thread.

So here is my Satsuki list:

Juko
Ai-No-Hikari
Osakazuki
Secchu-No-Matsu
Hayasahi-No-Tsutsuki
Gekko
Yama-No-Hikari

There are a couple on your list that I'm unsure about, but I think they'll be fine. Keep a close eye on the secchu-no-matsu, it's very slow and may need a little more attention. How big is it?

Going off of vague memory its about 3/4" thick at truck and 10-11" high. Are they okay with heat and sun? How special are they? It is one of the more interesting ones I have having the most unique leaves of all of my satsukis.

That's a nice start, bigger than I expected. It's not one you see much of. I don't think it's weak, as much as it's slow. Sometimes white flowered plants can't take as much sun as their pink counterparts. I'd keep a close eye on it.

Thanks for the heads up I hadn't known that.

I hear they can grow satsuki in the ground in the southern parts of the UK. I think that is zone 8a or even 9b. But apparently most don't do well in the other parts of the UK. Here in the Netherlands cultivar like Aikoku are not hardy while Kozan does seem to be hardy. That's zone 8b and 7a.
Kanuma city is zone 7a. They have satsuki in the ground there of course. I don't know if they are all under under plastic tunnels but I think most are.

But comparing European zones to the ones in Texas is going to be very different. I hear that for many satsuki the problem is actually that they don't harden off well with short cool summers. You won't have those in zone 8 in Texas I guess. Maybe summers will even be on the hot side of cultivar like Kozan, Matsunami etc.

I think in terms of minimum temperatures, it should be fine. If the temperatures drop slowly in autumn and if there is some mild frost they should be able to go into dormancy fine. And when they do they can normally take some frost.

I think that if you are near the coast with zone 8 then maybe that would be close to ideal for satsuki azalea.

I talked a bit through email with a satsuki shop owner in Omuta, Saga. He said that this summer he waters his bonsai twice a day. Surely they will be in 100% kanuma. Climate just as hot as southern Japan but a lot drier can have issues. I won't be surprised if he also uses shade cloth. I am sure Russell can tell you more. Satsuki can take the heat of zone 9 and 10. But how much shade and how much water they need I don't know.

You can find some hardiness numbers for satsuki on these pages:
http://www.azaleachapter.com/listofaz.htm
Many seem to be hardy up to 10 or 0 F. Some have no number given. I don't know if this means they are more tender or if it is just unknown. Probably the latter.

Glaucus wrote:I talked a bit through email with a satsuki shop owner in Omuta, Saga. He said that this summer he waters his bonsai twice a day. Surely they will be in 100% kanuma. Climate just as hot as southern Japan but a lot drier can have issues. I won't be surprised if he also uses shade cloth. I am sure Russell can tell you more. Satsuki can take the heat of zone 9 and 10. But how much shade and how much water they need I don't know.

You can find some hardiness numbers for satsuki on these pages:
http://www.azaleachapter.com/listofaz.htm
Many seem to be hardy up to 10 or 0 F. Some have no number given. I don't know if this means they are more tender or if it is just unknown. Probably the latter.

Glaucus,

Parts of the southern UK may be zone 8 or 9 as far as temps go, but I doubt they get the intensity of sun that we do in the coastal Deep South. I don't recall any of the nurseries around Kanuma using shade cloth, but it wouldn't surprise me if they do - and especially in southern Japan. The plastic I saw on those tunnel houses was for winter protection and pulled up or removed during the summer. After the first frosts and hard freezes that's how we stored all of the satsuki for winter - masterpieces and training material alike. Even on the coldest, dreariest days we pulled up the side panels during the day and let them back down for the night. Just to clarify, my point about commercial azalea production here is that full all day sun doesn't seem to be a problem as long as they're watered appropriately. Personally, I think some shade is the way to go here.

The problem with most hardiness info is that it usually only provides the minimum temps a plant can take, but not the maximum and certainly not for how long a plant can endure heat and humidity. "Hardy to zn6" doesn't really tell me what I need to know. One of our biggest problems here are our high summertime night temps. Many plants will do fine here until we get to July and August. Some plants just give up, while others like azaleas such as Kinsai (which, by definition, should be perfectly happy here) linger for a few years. Satsuki is such a huge and genetically diverse group of azalea that it's easy to give a general zone range, but far more difficult (and sometimes expensive) to determine the actual preferences of particular varieties. For us in this part of the country, "hardiness" means something completely different to someone living in, say, Wisconsin or Idaho or Switzerland.

Yes it will surely be very different. Like I said, I think the problem with satsuki here is probably the lack of long hot summers and occasional very early or very late serious frosts. Europe is very northern compared to the US but kept very temperate by the ocean currents. The southern tip has a very special climate. Very cool summers for a zone 9. Sounds to me that a zone 8 in Texas is the exact opposite.

And here we can have serious frost all day long for a period of a week during some winters. Satsuki seem fine if they freeze solid during the night, once they are in dormancy. But if they freeze solid for days straight and the plant is exposed to winter wind and sun, that will dry them out. As long as it is frozen, the roots can't absorb moisture. I hear this is what kills most azalea and rhododendron here. This is also a difference with Japan where in the colder parts it will snow and the snow will protect the plants during the coldest weather.

Japan can get quite hot in some parts, but it is also very humid. If you live in an area that is even hotter and has very dry air during that weather, I dont know exactly what that will mean for azalea. Azalea roots like to be moist. But with kanuma soil or similar fast draining potting mixes, you can't really overwater. I once heard some California people say that they can't really bare root satsuki in their climate. An Australian satsuki expert who went to Japan often noted that if there is one thing to learn (for Australians) from the Japanese is that they water a lot.
Still, azalea like their hot weather when compared to most other rhododendron and satsuki like their hot weather when compared to most other azalea. You probably already know how much to water in Texas during the summers.

And when a plant is a bonsai and in a pot, things are also different of course. They will be more vulnerable in pots as they will freeze ealier and get colder faster.

Ooh one other important thing when you plant them in the ground, you need to have the right type of soil. They will need soil with ph between 4.5 and 6 or so. Peat is normally the go-to cheap product for all rhododendron species. In Europe all rhododendron and azalea nurseries are near peat bogs. Kanuma City means 'deer swamp' so I think that being a peat bog has something to do with why so many nurseries are located there. Often peat is milled into very fine particles. You ideally want course peat. It has to drain very well. Any water that doesn't drain can and will rot away the roots. That's why the Japanese like to use Kanuma soil because their rainy season can be quite extreme. This is why you can also add in pine or fir bark. You dont want the soil to compact and turn into mud. Airiation is important. Many rhododendron and azalea people also like to use a thick layer of mulch. Oak leaves and pine needles seem to be liked. It will help keep the roots cool during the very hot weather. Azalea roots need to be planted shallow. You don't bury the root ball. But you can cover it with mulch.

Here you can see some pictures of large bonsai in full ground in Kanuma city at Shibue nursery:
http://satsukimania.net/index.php/map/shibue-satsuki-bonsai-garden.html

I don't know the details.

Hi All,
Hy Glaucus thanks, great site from Shibue Garden in the Kanuma aerea.
I saw that sealant pistol in the greenhouse,
he really is using normal silicon for bath tube and water piping to seal the wounds.
Some nice trunks there.
Sunip

If you give azaleas the chance to grow roots instead of tops, they will. I don't even pot them up until I have to (when they get big enough to dry the pot out too quickly). You can grow them faster in pots. Put them in the ground, and they will just stay in idle. The pots need to be no more than 6" deep... they may not root well into standard nursery pots. I use bulb pans. When I lived in FL I could grow the bejeebers out of them. In Minnesota, not so much.