Alternate soils for azaleas?

[KiwiPlantGuy]

It's a water soluble fertilizer, by miracle grow.

Hi,
Just wanted to add my baby Azaleas into the mix and this thread. They are my first bonsai soil trial mix.
My recipe is 50% pine bark (3-6 mm), 25% Pumice ( 3-4mm), and Zeolite (3-4mm). Best ingredients I can source at cheap pricing. The Zeolite is bagged up for Cat litter, but says (Natural Zeolite) on outside of bag.

So my questions for you and/or others is- Is my mix acidic enough with the pine bark as both pumice and zeolite are very alkaline ( pH 7-9 I think)?
Without a pH test I can only go on how the plants are growing ( look ok).
Also, do I need to worry about putting a small bit of Iron Sulphate on each pot?
Charles
P.S. I looks like the poor evening light has given them all yellow growing tips. Not a problem during day time.
View media item 4068

 

[just.wing.it]

Hi,
Just wanted to add my baby Azaleas into the mix and this thread. They are my first bonsai soil trial mix.
My recipe is 50% pine bark (3-6 mm), 25% Pumice ( 3-4mm), and Zeolite (3-4mm). Best ingredients I can source at cheap pricing. The Zeolite is bagged up for Cat litter, but says (Natural Zeolite) on outside of bag.

So my questions for you and/or others is- Is my mix acidic enough with the pine bark as both pumice and zeolite are very alkaline ( pH 7-9 I think)?
Without a pH test I can only go on how the plants are growing ( look ok).
Also, do I need to worry about putting a small bit of Iron Sulphate on each pot?
Charles
P.S. I looks like the poor evening light has given them all yellow growing tips. Not a problem during day time.
View media item 4068

Honestly I don't go for an acidic soil mix with mine, I rely on the "Acid Lover's" fertilizer for that.
I have 3 in completely inorganic mix.

 

[Leo in N E Illinois]

Hi,
Just wanted to add my baby Azaleas into the mix and this thread. They are my first bonsai soil trial mix.
My recipe is 50% pine bark (3-6 mm), 25% Pumice ( 3-4mm), and Zeolite (3-4mm). Best ingredients I can source at cheap pricing. The Zeolite is bagged up for Cat litter, but says (Natural Zeolite) on outside of bag.

So my questions for you and/or others is- Is my mix acidic enough with the pine bark as both pumice and zeolite are very alkaline ( pH 7-9 I think)?
Without a pH test I can only go on how the plants are growing ( look ok).
Also, do I need to worry about putting a small bit of Iron Sulphate on each pot?
Charles
P.S. I looks like the poor evening light has given them all yellow growing tips. Not a problem during day time.
View media item 4068

You can tell if your mix is not acidic enough, the leaves will become chlorotic. the veins will stand out as dark green against a yellowing leaf. Key is yellowing. You don't need a pH meter, the azalea will tell you. Root growth will be poor also.

I've had trouble with 100% Kanuma, especially if I do not sift the fines out. It seems to stay too wet. Other batches Kanuma have worked well. It is a hit or miss product for me.

Instead of Kanuma I use either pumice of perlite, as at least 50% of mix, orchid bark, usually used orchid bark from my orchids, about 25% and about 25% peat moss, I sift it, which means some bales only a small part will stay on my screen, but peat is cheap enough, and the fines go into the garden. My water is medium total alkalinity, around 190 ppm as calcium carbonate, azaleas do best if I'm able to give them mostly rain water, but they hang in there on tap water.

 

[KiwiPlantGuy]

You can tell if your mix is not acidic enough, the leaves will become chlorotic. the veins will stand out as dark green against a yellowing leaf. Key is yellowing. You don't need a pH meter, the azalea will tell you. Root growth will be poor also.

I've had trouble with 100% Kanuma, especially if I do not sift the fines out. It seems to stay too wet. Other batches Kanuma have worked well. It is a hit or miss product for me.

Instead of Kanuma I use either pumice of perlite, as at least 50% of mix, orchid bark, usually used orchid bark from my orchids, about 25% and about 25% peat moss, I sift it, which means some bales only a small part will stay on my screen, but peat is cheap enough, and the fines go into the garden. My water is medium total alkalinity, around 190 ppm as calcium carbonate, azaleas do best if I'm able to give them mostly rain water, but they hang in there on tap water.

Hi Leo,
Many thanks for your reply. I was probably concerned for no reason :-(.
Root growth is good, and leaves are green and active so I guess I am just impatient etc.
Also thank you for your answer re mix proportions and your use of pumice.
I am learning how to manage my watering needs with the use of Zeolite as this seems to be my best option along with pumice going forward. So these Azaleas are my trial. Next season I will try some other “hard to kill” trees to see how the trees respond etc.
On with the colanders and my pines/difficult conifers, fun times ahead.
Charles

 

[Leo in N E Illinois]

For me, in my area, zeolites are about 75% the cost of Kanuma and Akadama, in other words, expensive. When I did try zeolites, in proportions of 50% or more of the mix, I did not have satisfactory results, I felt they would release too much salt when the mix approached dryness. My collection is not on a automated watering system, so when I travel, I often inadvertently push the limits of drought tolerance with my trees. But when at or less than 20% of the mix, this problem seemed to disappear, Do remember this was not a ''controlled study'', anecdote at best, and would be dependent on my water quality and fertilizer frequency. If you have low soluble solids water, you might not see this at all.

 

[garywood]

Leo has some very good ideas on soil mix and I would offer one more about the use of excessive organics in he mix. Young plants are not a good gauge of soil mixes if you are thinking long term. Older azaleas that's been in bonsai pots for a long time can have their own "peculiarities". A very compact rootball where root zone problems can progress very quickly. Excess organics only add to the problem and are not needed if good growing principles are used.