Watering Azalea.

[fredman]

Sounds simple...well maybe it is, but there's a few things that concerns me.
I killed a few in the past by letting them get to dry. They don't show it immediately as other trees do (or maybe I didn't observe close enough). They get the drought damage, and just start deteriorating...and die a few weeks later.
It's easy to keep them wet..just water them to much. But herein lies my concern. I removed one yesterday that has been in a deepish azalea pot for about 3 years...highly organic soil that kept it's moisture...way to much. I was flabbergasted to see it's roots did not grow one half inch. I literally just lifted it out the pot as it was put in 3 three years ago.
Since I lost the others from drought i've been keeping the remaining ones wet...figured rather that than to dry. Big mistake to. To wet is just as bad...well almost.
What Paul Eslinger said in a video keeps ringing in my head...."if they are kept to wet, they get lazy and the roots don't extend".
Herein lies my other concern...where is that fine line with an azalea?
I mean, think about it...the right way then, would be to withhold water until the outer edge of the rootball starts drying before watering again. Well that's where the fine and delicate azalea roots live...and they can't take any drying out...!
I have two different soils to learn about to...kanuma and ericacious potting soil.
Man I have my watering work cut out for me this season...then again, hopefully i'm over thinking things again.
Anyway, I guess my questions are...How much do you water your azaleas? Do you let them dry? How dry?
Feeling the weight of the pot works for me with other trees, but I can't see it working with kanuma...it's soooo light, and I have heavy pots...uh uh

 

[just.wing.it]

I haven't used kanuma.....
My azalea has been happy for 2 years in a relatively small mica drum pot, planted in Lava Pumice and Douglas Fir Bark.
I honestly dont know what the Fir bark does for my PH levels, but I use Miracle Grow Acid Lovers water soluble fertilizer weekly.
I water once/twice per day.....usually morning and evening.

My very first attempt at Bonsai was with an azalea.....kept it too wet in organic substrate.....RIP.

 

[HorseloverFat]

I am also interested in this.... as I have noted different root growth rates on hardwood cuttings... i tried a few different(ish) blends of substrate.. so I will also share MY information as it becomes available.

 

[sorce]

It may very well be a lost cause in your wind.

On my way here, I was thinking about the ones I killed in nursery pots. 2 or 3. Always too wet, and forget winter!

Then I got to thinking about how Kanuma might be that soil that stays wet long enough to not have to water a lot, so the bark has a chance to dry out between waterings, and be watered only a little. They are naturally understory trees yes? Covered and usually quite bushy themselves?

So what if your need to water them so often as made necessary by the wind, is what is causing their demise?

My first thought was "don't water the trunk".

For thread graft points, maybe, with your ladies well, you just don't need anymore beautiful around, and the world is telling you to get rid of them!

Sorce

 

[Forsoothe!]

I have used the same organic media for 20 years. Some plants die every year, mostly failure to survive winter, maybe 1, 2, 3%. My climate has even moisture winter and summer, so I don't have to do anything after I mulch them in November or December. Any tree that is not growing is dying, one way or another. I can't imagine trying to water dozens and dozens of plants with different media in different size pots with substantially different needs and mentally customizing the amount of water tree-by-tree. How could that not be insanely tedious? It's bad enough with needing to place some trees in less sun to slow drying out because they have smaller pots or transpire at a higher rate, or both.

A good modifier of need is available supply. Each plant should be in a pot that supplies one day's worth of moisture. It takes some amount of time to wet-out a given pot and I spray everything with a hose and wet-out the foliage and intend that the water will trickle down from the canopy to the soil, too, but it still takes some amount of time spraying to insure that the pots have as much water as they can hold. I always hope to wet-out the whole rootball, especially the center. At any given repot, I can see that some trees won't grow roots straight down from the base of the tree, they grow only from the perimeter roots and I pot those in lower pots. Those trees that will grow from the center of the crown like Azalea are in deeper pots. Most of my trees are in deeper pots. I almost always over-pot by bonsai standards which may be the secret in my case. In fact, I think the "standard" ratio of depth to size of plant is silly on its face and probably only have a half dozen trees in pots that would be considered properly low by bonsai standards.

I also repot a whole lot more than is typical (I think), which contributes to keeping one day's worth of moisture capacity in each pot, the way I water, in my climate and exposure, with my media. It's a package of conditions.

 

[bunjin]

I only know what works for my climate but here are my thoughts:
1. It is best to have a mixed media that both retains moisture and drains well.
2. With azaleas, smaller pots are the most difficult to keep a consistent moisture content in them and therefore the choice of pot type is critical.
3. I have much better control of the moisture due to the use of an automated water system. I use spot sprayers, but other sprayers or emitters would work. The watering interval varies between every two days to every four days depending on the season. There are highly sophisticated controllers out there, but with the simple ones it is a matter of manually resetting the controller every few months.
4. In wet climates, a rain sensor would be helpful unless your azaleas are under cover. We get so little rain that I might shut off the system only a couple of times during the year to avoid over-watering.

 

[fredman]

It may very well be a lost cause in your wind

Ah mate i'm telling you, I fear this damn wind. It comes every year mid spring, just when the growth is nice and soft...so it can rip everything to pieces. Stays till summer. The wind as such don't do the damage...it's that viscious gusts in between. Some years it blows more than others. Some years it literally blows constantly...day and night
I have a cold frame, but can't use it when it gets to hot. The plastic cover gathers to much heat. Last year I got myself a silver shade net, and it works beautifully. When the wind starts, they'll be going in there...but I have to many to all fit in. I'll fit the maples and azaleas in though. This year i'm ready...

 

[fredman]

Some interesting comments...thanks.
I also observed when I watered the kanuma in...it wets the top layer but under it stayed dry..maybe (hopefully) it was only because of the initial wetting. I dunked all the newly planted ones in a bucket with water.
Ah I have one to go...good for the 'azalea trim thumb'...only one broke the skin. I'm getting better at this. '

 

[JudyB]

I think that you should try the Kanuma, I think you'll find it's not so hard to determine when you need to water, as the soil changes color when drying out. And it's unlikely that you'll have the same problems with the massive amount of water retention you had with the organic soil that you were using before. I imagine that you'll find in your dry and hot climate, you will be wanting to water more than you were with your previous soil, as it doesn't hold water like organic. Yes, for the inorganic substrates, it does hold more than most of the others, but in comparison with organic it is much quicker to dry out.

 

[fredman]

Another thing I would like your opinions on plz. When I planted them, I put a thin layer of kanuma over the roots. I then put a layer of sphagnum moss over...but then later got thinking...is it really neccesary?...I want the kanuma to dry out fairly quick, and by covering fully it might stay wet to long...plus I can't see the colour change when the kanuma dries. Maybe in high summer cover it fully.
Rest of the time only cover the trunk area....?
You have any thoughts on that?

 

[fredman]

I think that you should try the Kanuma, I think you'll find it's not so hard to determine when you need to water, as the soil changes color when drying out. And it's unlikely that you'll have the same problems with the massive amount of water retention you had with the organic soil that you were using before. I imagine that you'll find in your dry and hot climate, you will be wanting to water more than you were with your previous soil, as it doesn't hold water like organic. Yes, for the inorganic substrates, it does hold more than most of the others, but in comparison with organic it is much quicker to dry out.

Thanks for that Judy. Im looking very much forward to using the kanuma. I'm confident i will get along with it. Beautiful looking substrate it is to.

 

[Clicio]

Sounds simple...well maybe it is, but there's a few things that concerns me.
I killed a few in the past by letting them get to dry.

Well, I know this feeling, being known as Azalea killer, myself.
In my case it started with underwatering, roots being dry and they dying. No, they are not pines.
Next batch was the opposite, overwatering. On inspection, black sodden roots.
Nowadays I manage to keep two Kurume In very aerated semi-organic mix and deeper pots, watering almost every day all year, exception being twice a day in the summer when it doesn't rain.
Winters here are very dry, and summers very wet but very hot.
Both are alive and growing.

 

[fredman]

With azaleas, smaller pots are the most difficult to keep a consistent moisture content in them and therefore the choice of pot type is critical.

Indeed. I tried to go for the smallest pot the roots could fit when i replanted them now. The pots still looks to big though. I could could've cut more off the roots, but they aren't in the healthiest of condition, so i erred on the safe side.

 

[JudyB]

I go for smaller but deeper pots for Azaleas, it seems to work well for me and my watering habits.

 

[Harunobu]

I don't have a good answer. When I first started growing azaleas, I had them in plastic pots with peat and perlite. Some of them died after winter by just not waking up. I actually think they dried out in winter. I usually didn't water in winter as they are supposed to be dormant and it is hard to say when they are really drying out. And we have a lot of rain in winter. But I kept them inside a lot during the most cold nights. Makes the most sense that they dried out. Only in late may they would start to wilt. But they should have woken up in early april. And they all did it the same way.

When repotting seedlings, I actually noticed just how wet they often were. Sometimes, I hadn't watered seedlings for a while. They were in peat/perlite and with moss growing on top. The most keeps things really moist. I had plants that I thought were desperate for some water, and then repotting them they would be really really wet. Again, these were in plastic pots, the cheap ones you use to grow seedlings.

This decided me to put all my plants in the full garden. And I only lost one so far. My 'Kozan' plants are all doing the worst out of all my plants. I suspect they have weak roots. I think others have noted that they are temperamental. They go really slowly in my climate. I don't know if they are different in Japan or NA.

Which is why now I am trying 100% kanuma in terracotta pots. There is only so much water these will retain. Everything else will flush. Yes, smaller pots will dry out quickly. But if you have a large pot with (partial) peat, but these bottom parts far away from the roots of the plant will never dry out until you let the actual rootball become bone dry. I am now actually trying to water near the trunk and the base of the root system, trying to avoid watering past the actual roots. I think there is some risk for this with kanuma, especially if they are in large pots. The water may drain past the roots and never fully wet the root ball.

But I also had one seedling die, that I think had potential, because I didn't water in time while it was sitting in the sun. So if it is sunny and warm during summer, keep on top of your watering. And let them dry out some more to try to prevent that very moist peat on the bottom of the pot when the weather is cloudy.

One other tip is that during flowering, watch the flowers. When it is in flower, there is actually a good indicator of how much water a plant needs. And this can be helpful as a guide of how often to water through the entire year. The flowers will lose firmness pretty quickly if the plant needs more water, And they will go limp way before the first leaves become damaged.

As far as leaves and lack of water, I have observed different behaviors. I have seen new growth on plants to completely limp and be undamaged, while previous year's summer leaves look fine. And then when you water when the plant is obviously lacking it, it goes back to normal with no damage, as turgor pressure is restored. But I have also seen plants get damaged on both spring and previous years summer leaves, burning only the tips, with no sign of lack of water through loss of turgor pressure. I would guess that new growth only goes limp when it is really new. And that during or after flowering, this loss of turgor pressure followed by a complete recovery can no longer happen. And that from that point onward, leaf tips will burn without an obvious warning.

Which so far makes me conclude that besides putting it in full ground or putting it inside a warm greenhouse with a shade cloth and increased humidity, the best thing may be 50 coarse peat and 50 kanuma inside a terracotta pot. With partial shade and plenty of watering during sunny summer days. If a plant is in the full sun during summer, that only makes everything more tricky without an obvious advantage.

With all that being said, I don't think I ever had plants that really suffered from too much water, except for chlorosis probably induced by wetness. I have never had the dreaded root rot. And we can have some pretty wet autumns and winters here.
I am supposed to be the 'azalea expert' here, and I am growing many plants and most do well. But I don't do much gardening or bonsai besides that. And still I don't feel very confident about growing them in pots. When I think back, I killed some pretty nice cultivar. I could name them, but it makes me sad. That's a shame.

Yeah, wind during freezing temperature can be a killer. They evaporate water, but are unable to take up any because it is all solid/ice crystals. Not sure if this is the wind you guys are talking about, since it is NZ in zone 9, or typhoon style winds.

On the sphagnum, I really have heard different things. I remember someone who went to Japan claim they always did that to satsuki bonsai n kanuma there. But I heard of another person that it is really bad, because when the sphagnum dries out, it will repel water and not wet again until soaked for a long time. I know that last fact is true. But I don't see how completely bone dry sphagnum is bad if it wasn't necessary in the first place. I doubt it will stop water from entering the kanuma and watering the roots.
I like the idea of not having any sphagnum, but if a climate is really dry/Mediterranean, I can see how they may be crucial. But then I would say 'don't put them in direct sunlight'. No reason to add something to keep the roots cool if the roots aren't exposed and if the tree isn't in direct sunlight. Use the sphagnum drying up as an indicator? Maybe.

Lifting the pot and feeling how heavy it is; that will only help you if you already know exactly how much you need to water, and if you know from experience to compensate for the size and judge the density from the weight. That is not going to be a silver bullet. And if you have many plants/trees, you cannot lift them all individually. You just water all your plants.

 

[River's Edge]

Sounds simple...well maybe it is, but there's a few things that concerns me.
I killed a few in the past by letting them get to dry. They don't show it immediately as other trees do (or maybe I didn't observe close enough). They get the drought damage, and just start deteriorating...and die a few weeks later.
It's easy to keep them wet..just water them to much. But herein lies my concern. I removed one yesterday that has been in a deepish azalea pot for about 3 years...highly organic soil that kept it's moisture...way to much. I was flabbergasted to see it's roots did not grow one half inch. I literally just lifted it out the pot as it was put in 3 three years ago.
Since I lost the others from drought i've been keeping the remaining ones wet...figured rather that than to dry. Big mistake to. To wet is just as bad...well almost.
What Paul Eslinger said in a video keeps ringing in my head...."if they are kept to wet, they get lazy and the roots don't extend".
Herein lies my other concern...where is that fine line with an azalea?
I mean, think about it...the right way then, would be to withhold water until the outer edge of the rootball starts drying before watering again. Well that's where the fine and delicate azalea roots live...and they can't take any drying out...!
I have two different soils to learn about to...kanuma and ericacious potting soil.
Man I have my watering work cut out for me this season...then again, hopefully i'm over thinking things again.
Anyway, I guess my questions are...How much do you water your azaleas? Do you let them dry? How dry?
Feeling the weight of the pot works for me with other trees, but I can't see it working with kanuma...it's soooo light, and I have heavy pots...uh uh

Kanuma is easy to determine moisture content by the color change! Turns light as it dries out.
I use 100% Kanuma for established bonsai and a mix of regular inorganic with 25% Kanuma for cuttings and immature azalea plants.
It is important to sieve particle size, remove fines. I only use larger particle size on the bottom with medium and smaller particle sizes in the majority of cases.
The smaller the pot, the smaller the particles size to ensure both sufficient air and moisture retention.
Also, re potting is more frequent to ensure adequate root space. They grow roots at a very fast pace in good conditions.
If Kanuma is not available, I would choose pumice, lava, fir bark in small to medium particle size! Once again seived to size and matched to the pot size!
Overwatering becomes less of an issue when the mix drains well. proper choice of particle size and repotting every two to three years solves this issue.

 

[fredman]

I go for smaller but deeper pots for Azaleas, it seems to work well for me and my watering habits.

Yes that is what I gatherered from watching many azalea videos...Japanese masters. They use the small but deepish pots. I went for both flat and deep pots...will see how they go this year.

 

[fredman]

Kanuma is easy to determine moisture content by the color change! Turns light as it dries out.

True, but my mind says to me the growing happens at the edges of the rootball..the new fine roots move there, and they determine the growth. That's also where the first drying out occurs. The ball will stay moist for longer. Hopefully the top surface and the inner sides dries out at the same rate. That'll hopefully make it easier to see when to water...when the top colour changes, the sides are to...?

 

[fredman]

One other tip is that during flowering, watch the flowers. When it is in flower, there is actually a good indicator of how much water a plant needs. And this can be helpful as a guide of how often to water through the entire year. The flowers will lose firmness pretty quickly if the plant needs more water, And they will go limp way before the first leaves become damaged.

Thanks for that mate. Makes sense...i'll keep a eagle eye on that.

Not sure if this is the wind you guys are talking about, since it is NZ in zone 9, or typhoon style winds.

The wind is a temporarily seasonal thing. I'll manage that better this year.

Use the sphagnum drying up as an indicator?

The sphagnum definitely dries out faster than the kanuma. I'm not sold on the sphagnum. I'll keep it on the centre around the trunks for now. Will maybe cover again come summer.

 

[Deep Sea Diver]

I don’t know what’s up with your Satsukis @fredman, but not to worry about kanuma. Just don’t chopstick that stuff, especially when wet, it doesn’t really help at all.

Kanuma decidedly works for me. It drains well and the Satsukis really like it. But you gotta believe and then just leave the plants alone to grow out.

I use 80/20 Kanuma /chopped Sphagnum in plastic training pots with extra 1/4” hole drilled in the bottom for my newer Satsuki and mostly water the dickens out of them everyday. There’s moss because I shredded a bunch of Sphagnum and Mountain moss and spread it all over the surface. The sphagnum only dries on the surface, the interior never gets dry. I put them back in 70% sun last week after the heat wave. Despite all that, the kanuma drains and drains and drains. aka Walter Pall - same for fertilizer.

When it’s wet out, I’ll sometimes skip watering for a day or two and maybe chock them up when I want them to drain more.

I cut over 75% of the growth off these three (Pictured) In Feb where they were in the garage under lights. When these flowered in May/June I cut them back at least 50% again and to twos. All are in development.

Most of the rest are in the ground in 60/20/10/10 small bark/chunky peat/composted manure/soil above the surface which has a clay layer close to the surface.

As far as in ground planting, there is another post showing one of my small inherited azalea that had trunk and root rot issues. When things got bad, I tossed it into the soil with some of the rest (which are under huge Rhodes to give a quick mycorrhizal boost) It’s exploding with growth. I water it in maybe once a week and lightly wet it every other day.

Don’t Worry, plant em, keep em planted and watch them explode. It’ll happen.

Cheers
DSD sends