What type of azalea media (substrate) do you use?
- Thread starter Deep Sea Diver
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Sunwyrm
Mame
Sheer laziness and a great desire for less cancer later. I sifted for several bags with masks and goggles, then gave up since it was impossible to keep my dogs and toddler out of the area.
I suppose I should clarify, I don't sift but I do rinse it all through very well. The dust goes through the baskets I use. If I'm using a grow-bag, I'll rinse it through a basket first. Though I do have several large trees that I had to use 2 bags of DE on that I just dumped in the fabric bag. Quite a lot of dust went through but not a lot of smaller particles. I'll see how everything does by next spring when I'm repotting again, but I have checked on some roots, and (having never used any other soil) I'm really surprised with the results. I have crazy surface roots just scratching the top layer aside.
Here's some weed maples I pulled: Left 4 from Napa, right from the ground.
Leo in N E Illinois
The Professor
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In my climate, with our "relatively" mild summers, adding sphagnum to kanuma would make it retain too much water. My azaleas rarely need water daily, usually they can go 2 or 3 days between water, even in 90+ F or 35+C weather. Were I to mix in sphagnum, the mix would need to dry out for a week or more between watering. In desert climates, or if you use very small pots, the sphagnum makes sense.
DE, diatomaceous earth, - I will use Napa 8822 only with Dry Stall brand of pumice, as both have a very fine particle size. Years ago I stocked up on a more coarse particle size of DE, the source company has since gone out of business. The coarse DE is the same particle size as my pumice and lava. I don't usually reach for DE for azaleas, as Kanuma already holds enough water. Rarely, I add Napa 8822 to my "blueberry mix" to make a mix less susceptible to compaction. I usually use coarse DE as the water holding inorganic component for inorganic mixes for pines and conifers. Also use it for generic deciduous, like maple. But never at 100%.
Sifting will improve any soil. The more uniform the particle size, the more air voids the mix will have. Even a very small average particle size mix, if sifted to remove fines, and remove coarse particles, will hold a good deal of air.
A mix with both fines and coarse, will settle, and become like concrete, without air voids.
True, the above poster may have been "getting away with not sifting", and that is fine. Over the long term, I learned I need to sift my mixes.
DE, diatomaceous earth, - I will use Napa 8822 only with Dry Stall brand of pumice, as both have a very fine particle size. Years ago I stocked up on a more coarse particle size of DE, the source company has since gone out of business. The coarse DE is the same particle size as my pumice and lava. I don't usually reach for DE for azaleas, as Kanuma already holds enough water. Rarely, I add Napa 8822 to my "blueberry mix" to make a mix less susceptible to compaction. I usually use coarse DE as the water holding inorganic component for inorganic mixes for pines and conifers. Also use it for generic deciduous, like maple. But never at 100%.
Sifting will improve any soil. The more uniform the particle size, the more air voids the mix will have. Even a very small average particle size mix, if sifted to remove fines, and remove coarse particles, will hold a good deal of air.
A mix with both fines and coarse, will settle, and become like concrete, without air voids.
True, the above poster may have been "getting away with not sifting", and that is fine. Over the long term, I learned I need to sift my mixes.
fredman
Masterpiece
I started off using pumice and pine bark...3-5mm. That didn't work well. They started dying in the 2nd year. Out of desperation I took them all out and planted them in the ground. Could never understand why, but what Shibui said is hopefully the reason. I had very hard council water...Ph was over 8 most of the times. 2 years ago I installed a water filter system to the house...and garden. The Ph lately hovers around 7 also. Most are out and into pots again, so hopes are high again.
This year I have most in kanuma and some in ericacious potting soil that I added bonsai mix to.
This year I have most in kanuma and some in ericacious potting soil that I added bonsai mix to.
Sunwyrm
Mame
Right now, I've got a toddler, I've got a ton of pets; I'm enjoying this hobby, but it's not my only one, so I imagine I'll be shortcutting it for a long time. If sifting wasn't so very nasty, unsafe, and time consuming I'd do it. But there was no shortcut that I could find, and rinsing was so much faster with the strainer I was using to sift, then I realized I could just use the basket and save more time and less cancer-clouds. I have enough things trying to give me cancer without adding bonsai to the list.
I'm not rinsing fruit over here either, full blast with the hose to rinse out a strainer one at a time to fill a pond basket. I think the particles are pretty uniform for most of my trees, but I haven't checked down towards the bottom of the larger bags I was lazier with (for good reason, those trunks were monsters, and by the time I got them out of the ground and rid all of the clay I was dead). Actually really looking forward to seeing what's under there this next spring.
With Napa, I like that it changes color, I can't over-water (big deal with all the rain here) and I can skip a day if something happens and I don't get to water them. The only other thing I tried with azaleas was straight Perlite (I saw it on here). That dried up so fast and I killed 3 trees this summer from skipping a day here and there.
I'm not rinsing fruit over here either, full blast with the hose to rinse out a strainer one at a time to fill a pond basket. I think the particles are pretty uniform for most of my trees, but I haven't checked down towards the bottom of the larger bags I was lazier with (for good reason, those trunks were monsters, and by the time I got them out of the ground and rid all of the clay I was dead). Actually really looking forward to seeing what's under there this next spring.
With Napa, I like that it changes color, I can't over-water (big deal with all the rain here) and I can skip a day if something happens and I don't get to water them. The only other thing I tried with azaleas was straight Perlite (I saw it on here). That dried up so fast and I killed 3 trees this summer from skipping a day here and there.
fredman
Masterpiece
I was lucky (or is unlucky) this year. I bought 6 big bags of pumice...all wet, and double the effort to sift.
Few years ago I went to the wholesaler and sifted on the heap. Only paid for the size I wanted. Man I gulped enough dust that day to last me a lifetime. Couldn't feel my arms for a week
Few years ago I went to the wholesaler and sifted on the heap. Only paid for the size I wanted. Man I gulped enough dust that day to last me a lifetime. Couldn't feel my arms for a week
Harunobu
Chumono
Here in the Netherlands, it is considered bad science to wear a mask to stop viral infections that spread through respiratory droplets. So if I use a mask, people think I am crazy or infected or scared or not Dutch. So I used a mask while working with perlite. Not sure what the science says on having glass dust in your lungs, but it must not be good. I also know that sphagnum moss can contain fungal spores that might give you a very bad lung infection. Please use masks when working with dusty stuff. And those are the masks you don't want to use for coronavirus anyway (unless you work in a hospital with patients that are positive) because those dust masks don't filter the air going out, only the air going in.
The Napa thing confuses me. When I google it says it is 'Napa Oil Dry part no. 8822'. Where does that name come from? I can figure out it is diatomaceous earth aka minerals formed from sedimentation of diatoms aka algae with a silica cell wall. But Napa (valley)? Oil but no oil because dry? And what happened to number 1 to 8821?
The Napa thing confuses me. When I google it says it is 'Napa Oil Dry part no. 8822'. Where does that name come from? I can figure out it is diatomaceous earth aka minerals formed from sedimentation of diatoms aka algae with a silica cell wall. But Napa (valley)? Oil but no oil because dry? And what happened to number 1 to 8821?
HorseloverFat
Squarepants with Conkers
HorseloverFat
Squarepants with Conkers
I use DE/perlite/azomite (my standard non-organic mix) and add a mixture of perlite/peat/bark to “reshape” my original substrate towards Azaleas...
Time will tell if this is correct.
Time will tell if this is correct.
fredman
Masterpiece
Every time Napa is mentioned I think of Nascar 
Deep Sea Diver
Imperial Masterpiece
Respiratory protection is a relatively new deal to the general public. Even 15 years ago I had to battle science staff to take proper precautions to use, mix and store (esp) and to help educate them about proper precautions when using hazardous chemicals. Luckily it didn’t take them long to come around once the data was presented to them.
In the US you can still go to Home Depot and purchase numerous hazardous chemicals, splatter it all over, store incompatibles together in unventilated areas and generally muck about in an unsafe manner, blissfully ignorant of the hazards, things that trained folks would never dream of doing. Oh well..
Anyways, I would hope folks would always use an N95 mask at least, when sieving or pouring Napa 8822 or similar particles. Here’s the SDS. http://s7d9.scene7.com/is/content/GenuinePartsCompany/1814126pdf
As for perlite... Same thing when handling this stuff. Please use an N95 too.
It’s not the initial effect for respiratory hazards (although lots of them will put you in a bad way fast), sometimes, it’s the cumulative effect.
Cheers
DSD sends
In the US you can still go to Home Depot and purchase numerous hazardous chemicals, splatter it all over, store incompatibles together in unventilated areas and generally muck about in an unsafe manner, blissfully ignorant of the hazards, things that trained folks would never dream of doing. Oh well..
Anyways, I would hope folks would always use an N95 mask at least, when sieving or pouring Napa 8822 or similar particles. Here’s the SDS. http://s7d9.scene7.com/is/content/GenuinePartsCompany/1814126pdf
As for perlite... Same thing when handling this stuff. Please use an N95 too.
It’s not the initial effect for respiratory hazards (although lots of them will put you in a bad way fast), sometimes, it’s the cumulative effect.
Cheers
DSD sends
bunjin
Mame
DE as a substrate! Well, because so many members are using the Napa oil absorbent product, I am going to buy some to see what it is really like. It is apparently from a mine near Reno NV, and is a fresh water deposit. Now being a low level product, it is probably not very pure. There are not many sources of DE in the US. The local source that I am very familiar with has a lot sulfur in the their mined material and requires processing to make it usable for everything from filtering beer to laboratory grade filtering material. The high grades are very expensive because they are calcined, etc. I have not seen any DE that will not go thru a 1/16 screen, so immediately there is a problem. The native vegetation above the local deposit is very much deviant from the surrounding areas. PPD is always required to access the commercial site, so I would assume that one should have on a respirator when opening the Napa product bag. Any suggestions on how to evaluate this substrate are welcome.
James W.
Chumono
NAPA 8822 is discussed at length on this thread
fredman
Masterpiece
I dreamt about it last night....my azaleas in the flatish pots weren't happy. I'm going to take them out today and put them in terracotta azalea pots. Going to use a new mix to....50/50 kanuma and bonsai mix.
Don't know how to vote the mix up there.
It's pumice/bark/scoria/zeolite/biochar.
Don't know how to vote the mix up there.
It's pumice/bark/scoria/zeolite/biochar.
Deep Sea Diver
Imperial Masterpiece
Whoa...are you overthinking this... it takes a couple months for the system to settle down after a repot and flourish... ?
Best DSD sends
Deep Sea Diver
Imperial Masterpiece
You are correct, regretfully the software only let me list ten ingredients. Spaghnum was #11!@$!!
I actually use chopped spaghnum in my mix too... However I designed this using a couple of threads from 2016 on about what ‘Nuts used... sphagnum was down the list.
Be assured I’ll be including these off poll media ingredients.
Regards
DSD sends
fredman
Masterpiece
LoL, I overthink most things...but in this case, it was the right thing to do. They are much better off in the deeper pots. They won't miss a beat.
I was worried about mixing the softish kanuma with the harder particles, but wet kanuma is tougher that I thought. I mixed equal quantities in a bowl and tossed it like when I make a stirfry
bunjin
Mame
I think that if you are getting better results in a deep pot, it is because it is most similar to growing in the ground where the moisture content is somewhat constant. The reality is that the roots will not reach the bottom of the deep containers. l just repotted an azalea after 3 years, which was way overdue, and as usual all the dense roots were in a form of a toroid at about mid level in the root ball. I am working on a new strategy to encourage deeper rooting and it will involve putting the organics deep as opposed to the classic strategy of large inorganic particles on the bottom. Maruyama's practice of using plastic peanuts in the bottom of the containers is starting to make sense if the root ball will never really fill the container.
Deep Sea Diver
Imperial Masterpiece
I agree on a deeper pot for azaleas. Shallow pots for these trees are for show. My books from Japan show the azaleas in deeper pots when on site at the nurseries.
These observations make me wonder again about need for drainage layers in azalea.... due to causing the roots to not want to penetrate through the perched water table. Do you use a drainage layer? How much different is it in type and size from the growing media?
Or maybe the pots you are using are deeper than a normal azalea's roots would penetrate anyways?
Cheers
DSD sends
fredman
Masterpiece
It makes a lot of sense to me. Seems what is very important to, is the size of the deeper pot....the smallest one that will fit the ball. Just enough to be filled within a year or two.
Another thought...I wonder if azalea likes to be slightly rootbound...?
