Azalea-wars 2 Determining Signs of Trouble - From an inquisitive person

Hi @Deep Sea Diver,
Would you please be able to provide an average dilution rate for Humic acid. I realise all products are different so just a ballpark/average would be great!!
Charles
 
Sure thing.

For this Humic Acid product I use about 2oz/US gallon.

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Seems that would be in the ballpark for most Humic Acid, but not totally sure as I’ve only used two types…. same dose.

Cheers
DSD sends
 
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Interesting, so chronic fertilizing actually caused chlorosis?
Maybe the pH was getting too low even for azalea?

I believe the result would have been very different if over-fertilized with say urea or ammonium nitrate.
Humic acids are quite large organic molecules. Very different from salt-based fertilizer or small organic molecules.
So I wonder if what you observe is mostly a pH thing?
 
Ugh! So sorry. My entire write up just malfunctioned!

Argh!
DSD sends
 
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Interesting, so chronic fertilizing actually caused chlorosis?
Maybe the pH was getting too low even for azalea?

Seems perhaps like the roots were malfunctioning due to reverse osmotic pressure caused by excess fertilization, shorting the upper hamper of foliage of water and nutrients?

I believe the result would have been very different if over-fertilized with say urea or ammonium nitrate.
Humic acids are quite large organic molecules. Very different from salt-based fertilizer or small organic molecules.
So I wonder if what you observe is mostly a pH thing?

I think a similar effect would be shown, but I could be wrong. More later when I finish up.

But first I have to finish painting the trim on the west side of our house.

cheers
DSD sends
 
Some notes, Aftermath of Experiment One and Two and results of Experiment Three

Some notes

The west side house painting is complete! Time to finish this job….

I feel the need to preface my final results with a couple notes.

These are solely my results with thoughts and conclusions based upon my research, experience and present knowledge. Others may disagree. That’s ok, but I ask you to provide factual evidence to support your disagreement. That’s a lot more fun then seeing folks merely throwing out unsupported opinions… because they can in a modern world.

A very small piece about my azalea journey, for those interested.

I’ve grown azaleas in landscapes for over 50 years. About four years ago while on my bonsai journey I realized the only way for me to gather azalea bonsai experience quickly was to grow lots of azaleas (also pines and maples) from the ground up. I followed two bits of advice.

One from Jonas Dupuich, “Grow lots of one type of tree and you’ll learn a lot”

The other from Naka, Ota and Rokkaku‘s book, Bonsai Techniques for Satsuki where the authors mentioned ‘Azaleas can make and decent bonsai in five years and a good one in ten’. So azaleas were one of my first choices.

Over a year I gathered many middling, and some older, aged cultivars of all kinds of azaleas and am learning how to work on these plants as bonsai. These are azaleas of all kinds, not only satsuki (over 100 cultivars at last count), then I struck cuttings of these to grow whips and also learn more about the horticultural ins and outs of azaleas.

Thus my azalea experience to date is growing azalea into bonsai. This is one of the things which motivated me to do these experiments. It’s never fun for me to hurt a living thing, or even to prune radically. There’s always a sense of loss of what could of been. That’s why I pulled the plug soon and tried hard to get each plant to recover.

Experiment One and Two - Aftermath.

As you may recall, one of the goals of these experiments was to try to restore each azalea back to health after each trial. Regretfully, both Buccaneer azaleas in Experiment One and Two died. However there is good news on the Beni Kirishima front. Both have recovered and are ready for future work!

Exp 1 Beni K. Exp 2 Beni K

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Experiment Three - Over fertilizing trials results and conclusions

In last post things weren’t looking good for either azalea. Two weeks later their condition has changed…. for the worse!

September 17, 2022

Buccaneer Beni Kirishima


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Both azaleas

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Each study subject was damaged beyond recovery. Their condition is eerily similar to Buccaneer’s condition (root rot) in Experiment Two. Let’s take a look at their roots.

Root balls
Buccaneer (L) Beni Kirishima (R)


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Summary:

It’s obvious both azaleas are goners, each showing classic root symptoms. Its no wonder, as both azaleas were massively overfertilized. This seems to be the basic mechanism that occurred.

The fertilizer salts around the roots created an area of lower osmotic pressure in the media outside the roots, causing the water from inside the root cells to be drawn outside to restore equilibrium. This cause the roots to dehydrate. As this occurs, the first signs show leaves furthest from the roots being deprived of water. This is a result of losses from transpiration, coupled with the losses of water and nutrients due to the roots malfunctioning were too much for the plant to handle.

The Buccaneer trial showed this when entire leaf clusters at the end of each branch showed signs of distress. An uncommon experience for me. So now I need to be aware of this sign in other cultivars. However earlier experiments showed Buccaneer to be very reactive to shortages of water. So this conclusion seems logical.

Beni Kirishima‘s trial show Ed water/nutrient deprivation on the leaf tips first. A more common situation in my experience.

Likely there is more happening then described above, but this seems to be root cause.

Some Closing thoughts:

1. There were many ways each of these experiments can be improved.

a. The azaleas could of been in a bonsai media. This would of allowed better flushing, quicker drying, lower concentrations of fertilizer to be used and perhaps a higher chance of recovery from the excesses the plants were subjected to in these experiments.

b. The experiments could of contained more trials, more cultivars and perhaps different ages of plants

c. Finally the experiments should of started earlier in the growing season, allowing more time, especially the over fertilization experiment. This would of allowed a finer control over dosages and observation of changes over time.

2. Is the data sound? As a gross indicator of these three issues perhaps. Gaining validity would certainly need more trials.

3. Somethings to ponder.

a. The results do show the first type of fertilizer used, Osmocote Plus, didn’t seem to negatively affect the azaleas in the near term. In other words damage from over fertilizing with Osmocote Plus will likely slowly accumulate over time, rather then suddenly. I do use Osmocote Plus on all the azaleas, but have leaned to be careful with just tossing the product on, especially younger plants.​

For Example:​
When fertilizing azaleas in 2 1/4” pots (1st and 2nd year cuttings/layers) only 3 prills are used in early spring, followed by 3 more in early summer. These are not allowed to bloom as these azaleas always are grown out as whips.​
For 2nd - 4th year azaleas in 3” only 6 -8 prills are used early spring and early summer. If blooming one must be cautious to dump the prills out at least 4 weeks prior to the beginning of the bloom, otherwise the colors will be muted for solid color flowers and the color pattern “blasted” (my term) for multi patterned flowering azaleas. Then resume application after flowering.​

b. The results also show over-application of Miracid (Miracle Gro for azaleas etc) can have a dramatic and possibly catastrophic effect on the health of the azalea. I use Miracid/Humic acid/kelp as a regular supplemental fertilizer regularly at 14 day intervals, alternating with fish emulsion/Humic acid/kelp.​
There are distinct growth advantages to using Miracid for younger azaleas, giving robust growth. Yet when using Miracid, it’s best to be conservative. After all, it’s very easy to give a half dose. Also please remember to water prior to application.​
Finally, if one does a radical cut back, especially afterwards, I’d not use any fertilizer. Better to put the tree in bright shade for a couple weeks. If things look good and new growth occurs, one might use a very small dose, perhaps an 1/8 dose​
c. IMHO it is better to lay off the Miracid blend and perhaps very sparingly use the Fish Emulsion blend in hotter (not extreme) weather…. Or not at all.​
d. It’s risky to try to get in a fertilizer application in just before a heat wave strikes. Better to just wait.​
Aftermath: For those of you that stuck it about to read the entire thread, thank you very much!

cheers
DSD sends
 
Seems perhaps like the roots were malfunctioning due to reverse osmotic pressure caused by excess fertilization, shorting the upper hamper of foliage of water and nutrients?



I think a similar effect would be shown, but I could be wrong. More later when I finish up.

But first I have to finish painting the trim on the west side of our house.

cheers
DSD sends

Ah so in the other post, I do see their leaves completely desiccating.
I still would have predicted burned tips, though. But of course it also depends on how acute the problem is.
And maybe how fragile the growing tips are.

When I saw only the discoloration, I thought that maybe no osmosis was involved. Humic acid is a large organic molecule with just a few nitrogen atoms.
So in terms of mass, it only has a small effect on the osmotic pressure.
I kinda discounted the osmocote was it is supposed to prevent osmotic pressure desiccating the plant.
But I always forget that osmocote is time-based release, and not actually osmosis-dependent release as they kinda advertise.
Since you only saw the discolouration effect at first, I thought that maybe it was just a pH change that you were causing, not the osmotic effect of too many solutes in the root system pulling water out of the plant.

If you had used some liquid inorganic fertilizer with like ammonium nitrate and urea, I believe you would have seen the different acute fertilizer problem.
But good to know that even osmocote can cause over-fertilization.

As I grow azaleas mostly in peat-based potting soil with perlite, I do still kind of wonder what would happen if you have azalea in kanuma, and you apply liquid fertilizer at different rates.
With peat-based potting soil, you can just add some osmocote or slow release organic fertilizer chunks.
However, for azalea in kanuma, you kinda want to use liquid fertilizer if you have a lot of small plants.
Of course, kanuma as substrate should kinda prevent overfertilizing because you wash out excess fertilizer while watering.

Last year, I did add 2 or 3 pebbles (prills) of osmocote to all seedlings I transplanted, into 5x5 to 9x9cm pots. But since the potting soil contains fertilizer, I kinda stopped doing it.
I wonder though since I am in the Netherlands what our base nitrogen deposition values here are compared to other places.
There is now a huge debate about livestock farming and big industry causing to much nitrogen deposition and polluting nature reserves that have a nitrogen-poor biome, like heather fields.
If heather fields get too much nitrogen just from the air, maybe azaleas already in people's gardens already get enough without any fertilizing.
Still, I will probably fertilize my seedlings next year. Thinking about just watering with some liquid fertilizer and EDTA though.
The ones I have in kanuma, I need to put on another regime. I saw them become pale.

I was considering similar experiments, but I kinda didn't do them. I set apart some cuttings, but they are kinda too small and I didn't carry it through.
 
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Thanks for your thoughts!

I’ve switched about a dozen second/third year whips and plants into Kanuma. They each seem to be growing well. Perhaps Kennedy’s observation in the UK about kanuma doesn’t apply here.

These experiment took a real lot more to do then I first imagined, diving through literature and just observing. As you know, we both have a awful lot going on. 😎

cheers
DSD sends
 
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Delayed question regarding the over watering experiment. Was the metal bucket surrounding the plastic pot filled with water all the time, or was it emptied in between of watering rounds?

If filled all the time, so that the plant was standing in water - wouldn't the plant "drown" due to no oxygen too?

Sorry if I'm completely wrong here :)
 
Delayed question regarding the over watering experiment. Was the metal bucket surrounding the plastic pot filled with water all the time, or was it emptied in between of watering rounds?
Good questions! It was somewhat of a puzzling situation.

The bucket was filled all the time after the first day when the photos were taken. But both buckets were just about 3-4 cm short of the nursery container the plants were in. So a there was a gap simulating what a hidden flooding condition would be like.

The rootballs were constantly wet during the experiment despite the water level dropping up and down a bit. So a classic root rot scenario.

Most of the daily water loss during this summer experiment was due to transpiration, evaporation and the local wildlife (squirrels etc) which decided drinking out of the containers was more fun then drinking water from the watering dishes. 😎

If filled all the time, so that the plant was standing in water - wouldn't the plant "drown" due to no oxygen too?

I was wondering about this very question during the trials and still remain so today, but have thoughts.

The shallow roots not totally submerged could have kept the Beni Kirishima, being resistant to root rot, alive.
The Buccaneer‘s shallow roots likely did the same at first, but not being root rot resistant couldn’t overcome the infection, despite having some healthy roots.

This seems logical as the top 1/3 of the root ball is by far most active (Also why many folks unknowingly run into trouble by not taking care to see their plants are mossed In. A situation leading to constant dehydration in this important area.)

This highlights the situation with azaleas, being extensively cross bred, especially the Satsuki and Kurume azaleas as these species have industries supporting the demand for new azlaeas. So lots of variation in traits.

My bet is Beni Kirishima, being an ancient cultivar, likely has parents from area(s) where the plants not only are water stressed, but also heat stressed.

Cheers
DSD sends
 
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Good questions! It was somewhat of a puzzling situation.

The bucket was filled all the time after the first day when the photos were taken. But both buckets were just about 3-4 cm short of the nursery container the plants were in. So a there was a gap simulating what a hidden flooding condition would be like.

The rootballs were constantly wet during the experiment despite the water level dropping up and down a bit. So a classic root rot scenario.

Most of the daily water loss during this summer experiment was due to transpiration, evaporation and the local wildlife (squirrels etc) which decided drinking out of the containers was more fun then drinking water from the watering dishes. 😎



I was wondering about this very question during the trials and still remain so today, but have thoughts.

The shallow roots not totally submerged could have kept the Beni Kirishima, being resistant to root rot, alive.
The Buccaneer‘s shallow roots likely did the same at first, but not being root rot resistant couldn’t overcome the infection, despite having some healthy roots.

This seems logical as the top 1/3 of the root ball is by far most active (Also why many folks unknowingly run into trouble by not taking care to see their plants are mossed In. A situation leading to constant dehydration in this important area.)

This highlights the situation with azaleas, being extensively cross bred, especially the Satsuki and Kurume azaleas as these species have industries supporting the demand for new azlaeas. So lots of variation in traits.

My bet is Beni Kirishima, being an ancient cultivar, likely has parents from area(s) where the plants not only are water stressed, but also heat stressed.

Cheers
DSD sends
Okay, sounds reasonable. Good that you performed these tests and may we hope to never see these results on the trees we love
 
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