Help with Beech Leaves (fertilizer, water quality, pH)

Hello all,
Please take a quick look at these pictures and give me your opinion as to what might have caused this. It seemed to begin in early July as an inter veinal chlorosis on the newer growth and its mostly in the upper canopy, (leader and top branches) The bottom branches look unaffected. Its not a leaf scorch as my other Beeches have leaf scorch on the leaf margins and it of course looks very different.

Is/was this an Iron deficiency? Its an American Beech growing in pure turface. I have VERY hard water.
The tree has set nice buds and its late in the season so I'm not overly concerned. I have my theories but I would LOVE to know what went wrong here so I can avoid it next year.
All my best and my thanks-
-jay

My first geuss would be sun burn.

Second geuss would be high pH. Very hard water could be driving soil pH up, which would cause Fe deficiency and phosphorous deficiency. I would check pH before doing anything.

My last geuss would be potassium deficiency due to high Calcium and/or Magnesium in water. Low potassium leads to weak leaves that are prone to scorching.

Paul

Thank you for confirming what I had long suspected

After i made this thread I wound up reading an article about Beech Bonsai that claimed in no uncertain terms that Beech trees are EXTREMELY sensitive to hard water and should only be watered with rain water, they are just as sensitive as Azalea. I then read a study in which American Beech was subjected to various salts in their irrigation water and the results of the salt intolerance of American Beech even surprised the researchers, They stated that Beeches have no ability to control the translocation of salts within their tissues (apparently other trees do) and it is this proclivity that primarily leads to leaf scorch. As the salts in the soil are brought up and accumulate in the leaves.

So upshot is, its a Lime induced iron deficiency, my soil ph at this point is about 7.2, which is past the point of Iron lockup for this species, So treat your Beeches just like Azaleas. Rain water only! It was an eye opener for me!
-Jay

Would like to see the articles you speak about, could you provide some links.

I have Japanese white beech and they seem very susceptible to leaf burn, some more information on the subject would be welcomed.

Regards

Paul

Hi

I found it again. this is from SUNY apparently and of course they are talking and studying American Beech particularly but I'm ready to assume the salt issues would probably be found within the whole family, possibly even hornbeams too

amazing read that really opened my eyes.
http://treephys.oxfordjournals.org/content/4/2/167.full.pdf

Heres an excellent article about soil PH water PH the author also mentions salt uptake and leaf burning.
http://www.louisvillebonsai.org/post/2007/08/pH-of-Various-Bonsai.aspx

Thanks for the quick reply, the sodium toxicity article was very interesting.

I converted mM to ppm and it works out as 94mg Na / l. This is quite high, I would consider anything over 50 mg/l as becoming marginal for sensitive plants. As well total salts will also have a dramatic effect on marginal leaf burn, so final EC is something that must be monitored, or at least considered, when making up fertiliser solutions. However, Calcium and magnesium will help reduce sodium uptake, (and I thought these might have been a bit low in the nutrient solution in the article) and sulphate definitely reduces chloride uptake. A comprehensive water analysis will give you all the anions and cations in your water, as well as total alkalinity, it could be the best value for money spent while doing bonsai.

Unfortunately I thought a lot of the pH article was inaccurate. Total alkalinity is a more valuable parameter than pH alone. pH drift in pot plants is a nutrient and alkalinity driven phenomena, it is quite possible to have a pH7 with very high alkalinity. Additionally the pH buffering capacity of various potting components is a very short lived effect. I fact CEC and pH buffering in bonsai mixes is the greatest myth circulating about in the hobby. So things like peat, pine bark, will only effect pH until all H+ ions are removed/exchanged, which is only in the order of days for an alkaline irrigation water.

There is an excellent book called "Understanding ph management in container-grown crops" by William R Argo, and Paul Fisher. Meister Publications. This is an fabulous resource published for professional production nurseries which explains fully the infuence of different potting components and fertilisers on pH. If you are interested in this stuff, it is a must have book.

Good luck with your beech, I really like them as a bonsai subject.

Paul

Paul,

I think your absolutely right Its high time I had a professional water test and I will look into that.

I will also get a hold of a copy of that book as I feel I'm just on the verge of understanding PH.

Thank you so much for your 'much better informed opinion' than my own! I had to read your post twice but I did get it! So when we talk about adding an organic acidifier, we're only acidifying for a short time? Probably the time interval while the soil remains moist between waterings, or perhaps even a shorter duration until the H+ ions are absorbed?

Harry Harrington has suggested simply using a monthly treatment of distilled vinegar (with a 1/50 dilution0 And the use of acidifying fertilizers) to help maintain lower PH in an inorganic mix. I would be very curious as to your opinion on this.

Strangely last night I ran into a post on another Bonsai site that Walter Pall made warning about the intolerance of Beech and Hornbeam to the build up of salts in their medium, and that this can contribute to the leaf scorch.
-Jay

Hi Jay,

This is such a complicated subject and I find it difficult to explain it clearly, so bear with me.

Organic acidifyers only have short term effects. There is a couple of reasons, firstly they are only acidic because of where they were taken from, such as peats. Or as a result of decomposition/composting such as pine bark/woodchip. The acidity is related to the chemistry of organic materials; on the end of long chain molecules will be a structure which has a hydrogen atom which can be easily stripped off. -COOH ,carboxyl, is the standard one. (I can't paste an image into here, which would help) Carboxyl is drawn as one oxygen having a double bond with the carbon, the other oxygen a single bond with the carbon and the oxygen. In reality, oxygen is very greedy for electrons, and each oxygen atom wants the double bond, so the electron is effectively shared between the two oxgens, which weakens the hold of the hydrogen atom is it constantly switches form one oxygen to another. So if an alkali molecule passes by the hydrogen atom is easily stripped off the carboxyl group.

Theres only a finite number of these acid groups, and once the hydrogen is stripped off another cannot be made to replace it (only by further degrading the base structure as in composting wood chip) So if you are watering with hard water, which will have some alkali in it, eventually all the hydrogen atoms are sucked off and the pH increases. This supply of hydrogen atoms is referred to as the buffering capacity, but it is finite.

The fertiliser you use also affects the pH. Nitrate fertiliser is negatively charged, so plants excrete bicarbonate to balance the charge in the cells of the root, this forces the pH upwards. Ammonium and urea based fertilisers are positively charged (urea is neutral but degrades quickly to form 2 ammonium molecules), plants excrete carboxylic acid to balance the charge of the root cells.

Plants also excrete acid when phosphorus is low to try and strip P off soil particles.

The upshot is, the buffering capcaity of the potting media is shortlived, while the organic media may be acidic to start with, it soon drifts all over the place depending on the fertilizer you use and how much alkali is in your water.

I prefer to use battery acid (sound sharsh, but its just 35% sulphuric acid, H2SO4) to acidify my irrigation water, as it provides sulphate which is useful for plants. Acetic acid doesn't provide anything other than acidity and increasing the EC. I think you would need to do it more freqeuntly th every three months, thats because the pH can change in a couple of weeks, not months I adjust my fertiliser solution to a pH of about 5 to 6, which I use for 3 days straight, and then flush pots on the fourth day with regular water, and then fertilise again for another 3 days, from spring till leaves fall in autumn.

Build up of salts will only occur if you don't flush the potting mix regularly, or you are only adding enough water so that there is no excss to drain, because by definition, these salts are soluble and can be easily washed out. More than likely the problem with hornbeams and beech is not accumulated salts in the potting medium, but the salts that already exist in the irrigation water. That is why knowing the electrical conductivity of your water is so important. I put the upper limit of EC in the water for hornbeams to be about 1250-1500 microseimens /cm. Additionally, the salt levels in the leaves is cumulative, once sodium and chloride gets into the plant, it can't get out; the greater the transpiration rate is, the less the EC should be.

hope this helps

Paul

Paul

THANK YOU so much for that explanation, took me back to organic chemistry class there but that stuff is still floating around in my brain somewhere and I understood everything you wrote. Since I am just on the verge of understanding all this I am going to pick your brain a bit more if thats ok.

with my very hard water, does the calcium and magnesium build over time in the Turface. Does the Turface tend to accumulate it more due to its own chemical structure, being calcined clay. The tree obviously suffered what I have read is called Lime induced chlorosis, now did that chlorosis result from lime building in the soil OR the effect the lime build up had on the PH and thus cause a nutrient lock. Maybe it locked up more than just iron as I see possibly more than one deficiency.

is PH and the various ion effects really only something that happens when soil becomes liquified, when we water, hence when soil is dry a PH meter takes no reading, (seems like a stupid question but I'm still gonna ask)

Acetic acid was suggested as a monthly treatment, I found it will drop the ph about 3/4 point. But once the turface absorbs the vinegar/water solution a ph reading returns to neutral. How will that benefit the tree with regards to nutrient take up? Can roots only drink their food when saturated?

What do you use as a soil for your Beeches? What do you use for fertilizer?

When fertilizing with something like miracle grow, does that product build up salts in the tree, as well as the soil, we can flush the soil with rain water of course but cant flush the tree. Should we fertilize with organics instead (fish/seaweed emulsions) at least in the case of our Beeches.

I am FASCINATED by this. The challenge of "getting it right" for a tricky species is part of the fun of this hobby. For me its less fun to have someone point out "oh you have an Iron deficiency hit it with chelated iron" I want to learn WHY it happened. Particularly with this being my first year trying some trees in pure Turface. By the way, most all my trees don't seem to care about turface OR hard water they obviously have more forgiving PH and soil tolerances. But Beeches, Azaleas, Hornbeams these are a few of my favorite trees and I am definitely interested in learning how to grow these species in an inorganic medium.

I am your humble apprentice
-Jay

That’s a lot of questions, its going to take a while to get through them all but I’ll give it a shot. After all, this stuff is important, if you can’t keep a tree healthy you’re not going do too much bonsai. But next time, only ask a few questions, please.


with my very hard water, does the calcium and magnesium build over time in the Turface. Does the Turface tend to accumulate it more due to its own chemical structure, being calcined clay. The tree obviously suffered what I have read is called Lime induced chlorosis, now did that chlorosis result from lime building in the soil OR the effect the lime build up had on the PH and thus cause a nutrient lock. Maybe it locked up more than just iron as I see possibly more than one deficiency.

Anything that precipitates out in the soil will not harm the plant, it may reduce pore size, but it won’t hurt the plant. What hurts plants is the amount of dissolved salts in the soil solution. Now the amount of dissolved salts in your irrigation water only increases soil salinity if you add insufficient water to flush out excess dissolved soil salts from previous watering’s. The amount of water a course grain potting mix holds that is available to plants is very small. I say available to plants because most of the water in turface granules will not be available for plants, they cannot access it because the pores are too small. So a pot might hold about 100 ml of available water, if you add 90 ml, nothing will drain out the bottom. If you add 110 ml, 10 ml will drain out the bottom. Now if you add 100ml of water, with some salt in it, the plant will take up a little bit of salt, and the rest just sits in the pot. As the media dries out, some salts will precipitate, like calcium phosphate, this stuff is very insoluble so it falls out first, next might be gypsum, and last would be nitrates (these are the only salts that should be in your pots; sulphates, phosphates and nitrates). By the time nitrates start to precipitate the plant is looking very dehydrated so you water it again (usually before these precipitate out). If you keep only adding 100ml at a time, the amount of soluble salts builds up to a point where the salinity affects the plants ability to take up water. The insoluble salts (calcium phosphate) no longer have an effect on the plants ability to take up water. But we don’t water like this, we water excessively and the soluble salts from the previous watering are diluted, or redissolved, and flushed out. Except for the phosphates and gypsum, if it’s there, but these won’t hurt the plant because their solids. So salts only build up if you don’t apply enough water to flush the soil. Turface, although it’s porous, won’t hold soluble salts in amounts that are injurious to the plant because salts on the outside of the particle are at about the same concentration as the irrigation water, dissolved salts on the inside of the particle are not available to the plant (though they tend to move to the edge due to diffusion, which limits there concentration). This is why you shouldn’t crush the grains of perlite or turface when doing pH tests, because you release the stuff that plants can’t get to. It’s only the soluble stuff on the outside that’s important

Iron forms poorly soluble compounds with lots of things, carbonates especially, iron content in fertilizer solution, and irrigation waters, is very small anyway, it shouldn’t be anymore then about 10ppm, 1-3 is acceptable. If there is any bicarbonate in your water, it will form in insoluble complex with iron at about pH 7.4 (I think). So it is no longer available for some plants, like azalea, or beech, or petunia. Other species are very good at acidifying their root tips by excreting organic acids like citric acid, these dissolve the iron carbonates and make iron available. Plants that do this are pelargonium and anything else that doesn’t mind a high pH. (These plants fall over in low pH soils, from iron toxicity, the opposite to azaleas) Phosphorous also becomes unavailable at higher pH’s. So these are the two main deficiencies seen in alkali soils.
.

is PH and the various ion effects really only something that happens when soil becomes liquified, when we water, hence when soil is dry a PH meter takes no reading, (seems like a stupid question but I'm still gonna ask)
pH is the measure of dissolved hydrogen ions, so it by definition it only happens when in a liquid. pH can decrease (become more acidic) as water evaporates away from the solution, so sulphuric acid will get stronger if you leave the lid off the bottle.

Acetic acid was suggested as a monthly treatment, I found it will drop the ph about 3/4 point. But once the turface absorbs the vinegar/water solution a ph reading returns to neutral. How will that benefit the tree with regards to nutrient take up? Can roots only drink their food when saturated?

Plants only take up nutrients in dissolved ionic form. When you apply organic fertilizers you have to wait for bacteria and fungi to convert the organics into minerals. For example, fish emulsion will have a mix of inorganic nutrients like nitrate, and some organic nitrogen compounds, like amino acids. If your pH rises after adding an acid solution then there are un-dissolved carbonate salts in your potting mix, the acetic acid you applied was not enough to completely neutralize it, and so the pH rose again. Much better to use it more frequently; like daily! I think that’s a golden rule for fertilizing bonsai; a little bit, all the time. I don’t recommend monthly or quarterly feeds, and quarterly feeds of trace elements is a complete waste of time.

What do you use as a soil for your Beeches? What do you use for fertilizer?

My mix is 1/3 zeolite, 1/3 perlite(medium size) and 1/3 pine bark chips (we have a lot of monterey pine bark here in Australia) These plants also like high oxygen levels in their roots, so I aim for an air filled porosity of 25% in a 10 cm pot. I mix my own inorganic fertilizer, like a hydroponic nutrient solution.

When fertilizing with something like miracle grow, does that product build up salts in the tree, as well as the soil, we can flush the soil with rain water of course but cant flush the tree. Should we fertilize with organics instead (fish/seaweed emulsions) at least in the case of our Beeches.

Your getting into the problem of EC and nutrient balance here. I don’t like miracle gro because the last time I looked at it, it had a lot of chloride (chloride is toxic to plants)in it, and Urea. I know there are heaps of people who love it, but I wouldn’t touch it, or recommend it.

Plants only take up dissolved ions, these get to the cells inside the root by either diffusion, or in the flow of water. Plants take up other things, like dyes and the odd organic compound, but accidently, and then only of low molecular weight. With some elements the root cell has to expend energy to take it up; like calcium, magnesium, iron, copper. Others simply race into the root cell in an unregulated fashion, like potassium, sodium and chloride. Organic fertilizers are similar to inorganic, to a plant; they only “see” the ions. Also, these fertilizers can have high sodium content, which the manufacturers never discloses, it’s the concentration of salts that is important, hence constant reference to EC.

Inside the plant cell there is a high concentration of dissolved salts, mostly potassium (up to 1000x more than in the soil) this creates an osmotic effect and literally sucks water out of the soil. Plants don’t spend energy to take up water. As salt content in the water increases, the strength of the osmotic suck decreases. At some point, insufficient water is taken up by the plant and it dehydrates. This is different to windburn or leaf scorch. Some plants are more sensitive to dissolved salts than others so black pines handle salty solutions better than beech, or Japanese maple. Where a plant grows naturally is a good sign of their ability to handle salts. Plants in nature are used to this, but ground soil water naturally has very low dissolved salts, all the salts are on the clay particles, so they don’t really have to struggle with salinity, unless they live on the coast. Things are different in bonsai pots, the irrigation solution delivers the nutrients and plants can only handle so much salt, so you have to be careful with how much fertilizer you apply to beech and hornbeam, thats why it sbetter to have a little, all the time. All plants can suff er from this, any solution with an EC greater than the plant can handle will damage it. Also there is the possibility of over fertilizing, plants can take up too much of an element, or not enough of another, eg too much Calcium will inhibit magnesium uptake.

Leaf scorch happens when plants are hot and need to cool down, they do this by evaporating water from the leaf surface. They need lots of water to do this, and inadvertently take up extra salts like potassium, sodium, chloride (those that are unregulated and don’t require energy to be taken up). These salts go straight to the leaves, where the water evaporates away, cooling the leaf; the salts are left behind. The plant doesn’t need these extra salts, so they get pushed to the edges of the leaf, where it slowly accumulates, eventually becoming toxic to the cells at the leaf edge. This is why you never see wilting leaves with leaf scorch, it has nothing to do with insufficient water, a lot to do with soil salts. Beech, hornbeam japanese maple, are all cool climate plants, they don’t like hot places, so they have higher transpiration rates at temps other plants are comfortable in. To help prevent leaf scorch, fertilizers must be of lower concentration then spring or autumn. Some things that will help, calcium and magnesium prevent the uptake of sodium, sulphate stops chloride, low EC solutions in summer with low potassium and nitrate in ferts will help prevent marginal leaf scorch. Keep transpiration rates low by keeping plants out of hot sun, only early morning sun.

Hornbeam, beech and Japanese maples are my favorite plants as well, I struggle with leaf burn as well.

Paul

63amp
We touched on this topic on another thread a while back. If I may can I ask a couple of questions.

What or where can I find a list of basic water quailities or parameters prefered for container growing?

Is there a water filter or treatment system to rectify these defenciencys and where can I go to research and or purchase a home unit?

Thanks
Mitch

http://meistermedia.com/store/ has the William R Argo, and Paul Fisher book on pH for $20 WITH BUY ONE GET ONE FREE and free shipping. Amazon listed it for $80.

63amp- thank you for the detailed info. I have one question. How does "soft" water come into play here? I had my water professionally tested as I was having brown tips on maples. I have used this year a fertilizer formula called MSU popular in orchid culture and I have had less brown tips this year. MSU for RO water formula is 13-3-15 with 8 Calcium and 2 Magnesiun

My water analysis showed:
CA=11 ppm
MG=2.4 ppm
Alkalinity(as mgCACO3/L) 35
EC(mmhos/cm)=0.12
pH 6.95

I'm sorry paul, I think we may have opened the flood gates

I want to really thank you for all the help you've been, your obviously very knowledgable and very generous with both that knowledge and your time. People like yourself are what makes this forum such a unique gift for the rest of us.

I too had wondered about the salt content of fish emulsion. Actually it was around the time I switched from Miracle grow (love it or hate it) to fertilizing with pure Neptune's harvest fish and seaweed that I first noticed the chlorosis beginning.

I'll only ask one question this time. Do you feel as I do now that simply switching to rain water (which I can do easily) may solve some of these issues. My Beech has been flooded with nothing but hard water all growing season, do you think I should give it a good flushing with rainwater before applying my Iron Chelate? You seem to return often to the idea of a good flushing out of the soil as an important horticultural practice with Bonsai, yet it does me little good to keep flushing with hard water I would imagine.

Ok thats two questions

I'm getting the book and am preparing to have my water tested by Cornell Univ. I actually have a captured spring as my water source and my once clear shower curtain liner is now white after only a couple months.

I'm going to re-read your post again now
Thank you so much again for your time sir.
-jay

What or where can I find a list of basic water quailities or parameters prefered for container growing?
Is there a water filter or treatment system to rectify these defenciencys and where can I go to research and or purchase a home unit?

Hi Mitch,

Best place to look for water quality information is production nursery, horticultural or hydroponics literature, you won’t find anything in bonsai literature. Recommendations will be fairly varied, and of course water quality is plant species specific. Often there are tables with ranges for plants with different salt sensitivities, these tables are often related to vegetables and commercial nursery plants often grown in green houses or under shade cloth. There is nothing specifically on Japanese Maples, hornbeam or beech. But my experience is the upper limit for EC is 1250 -1500 microS/cm in summer. The Oz book, Growing Media for Ornamental Plants and Turf has 3 pages of species and their salt sensitivity and doesn’t mention Acer at all (puts snapdragon, berberis and cedrus atlantica as very sensitive). Their criteria for sensitive plants is max EC of 1.8dS/m, which I personally think is too high for J maples, (because I can grow snapdragons with ease but my maples are much harder to keep looking nice).

Here’s some information you might find interesting derived from different references in a hydroponics book. Note the variations

1. Max concentration (mg/l)

Sodium 50-100
Chloride 50-100

2. Zero Degree of problems
EC <0.75 dS/m=mmho/cm
TDS <480
Sodium (sodium adsorption ratio) <3
Bicarbonate <40mg/l
Chloride <70


3. Desired levels
EC 0.2-0.5 mS/cm (= mmho/cm = dS/m)
Alkalinity (CaCO3 equivalent) 40-65 ppm (0.8-1.3 meq/l)
Sodium <50 ppm
Chloride <70 pm
SAR <4
K <10ppm
Calcium <60
Sulfate <30
Magnesium <5

4. Excellent water suitability for potted plants

EC mmho/cm <0.25
Total dissolved salts <175 mg/l
Sodium % of total solids <20

5. Max levels allowable for general hydroponics

Calcium <200mg/
Carbonates<60mg/l
Chloride<70mg/l
Sodium<180mg/l
Zinc <1mg/l

I personally think the lower the better for everything, rain water is the best option, (don’t collect it off a galvanised iron roof because zinc can cause problems). My own water has sodium 24 mg/l; Calcium 16 mg/l; chloride 50mg/l; calcium 7mg/l; magnesium EC = 0.36mS/cm; alkalinity 109 mg CaCO3. And I found this gave me chloride and sodium problems with hornbeam, beech and Japanese maples, and drifting pH; until I changed my fertilizer regime and then things improved.

Rain water is best if you can collect it, but reverse osmosis will give good water quality, though it’s expensive. Avoid water softeners as these simply pump sodium into the water. It’s really important to get a comprehensive water test done, it’s the only way of knowing what you are watering with, and it may be possible to work around what you have, eg diluting with 50% RO water may be an option, and cut the cost by 50%. Knowing what your sodium and chloride are is essential, these cause the most problems. (knowing Boron and Flouride is handy too)


How does "soft" water come into play here? I had my water professionally tested as I was having brown tips on maples. I have used this year a fertilizer formula called MSU popular in orchid culture and I have had less brown tips this year. MSU for RO water formula is 13-3-15 with 8 Calcium and 2 Magnesiun

My water analysis showed:
CA=11 ppm
MG=2.4 ppm
Alkalinity(as mgCACO3/L) 35
EC(mmhos/cm)=0.12
pH 6.95

Hi Frank,

I remember discussing your MSU orchid fertilizer. I thought it was a good product, has it helped your plants?

About your water, it seems really good from the numbers you’ve given, and I’m jealous of your low EC. But water is just the starting point, it’s the EC of the fertilizing solution that dictates the upper concentration of your fertilizer, and a measure of what plants can handle. Because as EC rises, the plants have trouble taking up water.

I worked out my homebrew mix (version 4 so far) is something like 12.5: 1.3: 5.2 Ca 7.4, Mg 4.4 (Your American numbers when converted to elemental percentage is 13:1.3:12.4 Ca 13.7 Mg 1.2, Its spooky how close the N and P values are, Ill think aboiut the K value) While the ratios of the MSU fert is OK (though the Ca looks high and Mg low), you have to look at the EC of the final fertilizer solution; and how much sodium and chloride you have present if there is any. Looking at you water analysis, I think you have good water quality and they shouldn’t be a real problem; here EC of the fert solution is the important factor.

Lots of things cause brown tips in Japanese maples besides chemistry; low air filled porosity and over watering of foliage are a couple of things off the top of my head. Sometimes they just brown off for no apparent reason.

Having good quality water really helps as you have room to maneuver, there’s no worry with unwanted elements and you can change the strength of the fertilizer solution to match the weather quite easily. With my water, I’ve already used up a third of my target EC with the irrigation waters EC, so my final fertilizer concentration would be less than what could be achieved if I use rain water instead. And fertilizer concentration is an important component of feeding.


I'll only ask one question this time. Do you feel as I do now that simply switching to rain water (which I can do easily) may solve some of these issues. My Beech has been flooded with nothing but hard water all growing season, do you think I should give it a good flushing with rainwater before applying my Iron Chelate? You seem to return often to the idea of a good flushing out of the soil as an important horticultural practice with Bonsai, yet it does me little good to keep flushing with hard water I would imagine.
Jay

Hi Jay

Rain water is the best, if you can use that, then do it. You also need to do something about carbonates and bicarbonates, as these will lock up the Fe fairly quickly at pH of 7, so you won’t get a good response to your Fe. Flushing won’t remove the carbonates, but adjusting the pH of the rain water with your acid for a few days will do it. Just don’t make it too acid, pH 5.5 will do, and keep doing it until you see a persistent change. When you flush with your hard water you keep adding alkali, so you keep building up your carbonate levels.

Hope this helps

Paul

Paul I have less browning tips on tridents and japanese maples with the MSU. It did not completely eliminate them but it did help. I added a shade cloth in July and that helped in the 100+ degree days. This summer was one of the hottest on record here in Ga.

I want to point out that most vendors who sell the "MSU Formula" have two variations depending on your water source/quality. One is for RO water and has extra CA and MG. The other is for "city water". I use the one for RO.

Thanks for sharing your knowledge

Frank

Paul
can I flush with rain water to remove the carbonates?
-jay

Thanks Paul
I have been waging war with trying to keep maples and azaleas for a number of years now. I know I am a slow learner, I could never figure out why I was having so much trouble with certain species of plants when friends near by had no trouble with them. About a year ago a gardening friend showed me his water analysis and it blew my mind. I never figured the water quality was so low.

I am now going to set up rainwater collection system. From what I have read from this thread is that I will still have to test the PH and adjust as needed. How do you recommend to do so? What type of PH meter do you recommend? Any other things to look out for.

Again thanks for you knowledge and patience.

Mitch Thomas

Hi Mitch, Frank and Jay

I'm glad your finding the information interesting. It gets fairly technical very quickly so I hope its understandable.

I have a pH meter but I don't use it, I use those aqaurium pH color testers for pH. The ones with the universal dyes, about 10 drops in some solution and compare color to chart. These are accuate to about .5 pH units and very quick.

I have an EC meter though, which I pull out everynow and then, I really only check EC when I change my mix, or about every few months to make sure my well water hasn't drifted. With a meter you also need a standard EC solution to calibrate the device. It won't store for a long time, so you have to make up a new solution each time you use it. That means, some lab grade chemical, a 3 decimal place balance and a volumetric flask. You can buy pre-made solution, but its about $20 a bottle, that's a lot for a single go.

I think its better to find a pool maintenance centre, or hydroponics shop, even an environmental lab (say you don't want a written report and you might get it cheaper) and get a quick EC done there. Once everything is settled you only need to test every now and then.

Summers in my part of the world get hot as well, I find different cultivars respond differently. Mine get different amounts of sun. Coralinum burns very easily under shade clothe from 10am with Beech and Hornbeam (Rock hornbeam more tolerant of sun than American hornbeam (no direct sun for Am hornbeam)), Kashima and Shindeshojo are pretty tough, sun till about 1pm, regular JM in shade from about midday. No fertilizer other than Ca Mg SO4 (to combat Na and Cl) in hottest part of summer.

Maples need excellet O2 supply to their roots, they die really quickly from root diseases, even water pooling under the pot after watering will kill them, make sure all plastic pots are 5mm off the bench, and tilt any shallow bonsai pots for a couple of hours after watering (I use a10cm plastic pot under one end).

Paul

Paul when we use liquid fertilizer even with a high CEC (33) substrate like Turface does the ion exchange in the root system The actual absorption of the nutrients, end after the last of the nutrient solution finally drains from the pot? (or close to it) Is this why we can fertilize more often with a completely free draining inorganic mix because the actual fertilizing really only starts with the liquid hitting the roots, flowing on and around them then slowly draining out thus ending the fertilization for that application? What about the residual fertilizer fluid that is absorbed by the Turface, does that enter into liquid suspension again, say on the next clear watering, and we get a little bit more fertilization effect albeit diminished? Am I correct in thinking that a Tree in an inorganic substrate really only cares about the PH when its feeding time, and thus the PH of the nutrient fluid when it surrounds the roots during that watering-in is what were after with regards to effective ability to get nutrients to the plant without lockouts. You can just answer Yes to these The thing is I think I'm finally getting why its better to go inorganic and how this very closely resamples Hydroponics

In experimenting with PH today I noticed that when I stuck my ph meter into dry turface, switched it on and then watered all around it with an acidic solution I was able to watch in real time the PH lower, then slowly return to the original value of wet turface (which is 6.5) and I though "thats just like the fertilizer entering the substrate, effecting it for the duration of the watering, then leaving and all returns to baseline." And it clicked! Thats what the fertilizer must do as well

Hi Jay

CEC is a tricky thing to understand. It all sounds great the way those who sell it say it works, but alas, its not that simple. CEC works great in soil, out in the paddock where pore size is small and root hairs are in touch with a lot of soil. In the paddock the soil solution has a low EC, the majority of nutrients are bound to clay and soil colloid surfaces. The plant extracts these by releasing acid to exchange the cation off these surfaces. Reality is, bacteria and fungi collect the majority of nutrients for plants becaue they are in closer contact with the soil particles, they excrete acids to remove the nutrients, the plants pay off the bacteria with sugar.

In a bonsai pot, the pore spaces are huge, and root hairs aren't really that closely connected with the surfaces of the small pores. and there isn't a lot of closely connected microflora. So while palnts do extract some of their nutrients off the surface of the turface grain, its not a lot of nutrient. Next time you repot, have a look at how closely connected the roots are with the soilids, not all that tight. In bonsai pots, plants get the vast majority of their nutrients from the water we give them. The plant will feed off whatever is in the solution until it becomes too concentrated (because of plants extracting water) to extract any more water, the high salinity problem. Plants only see nutrients that are disolved in the water. So bonsai using inert material, such as turface, perlite, zeolite, vocanic rock, pumice, etc. IS a form of hydroponics, called Inert Media Drip Irrigation.

There is also a down side to CEC, copper and a few other trace elements are strongly bound to the substrate surface. because of all the salts we pour onto the media, the area is saturated with things like K, Ca, Mg, Na, so when a plant goes looking for Cu it can't find any becuse all its stripping off the substrate is these less strongly bound elements. So if your only using trace elements once every 3 months on turface, more than likely your plants are trace element deficient. It takes a few weeks to "fill up" the exchange sites with a base load of copper, after which the plants can extract it.

CEC is another one of those myths. It doesn't really do anything in a bonsai pot.

The porous turface grain will harbour carbonates and other precipitaes, and quite alot, so thats why you see the slow rebound in you pH. It takes a while for the H ions to migrate into the particle. If the partcile fizzes when submerged under strong acid you know it has lots of carbonate.

By the way, Mitch wanted to know what other things he could do to help his maples, I just remebered keeping roots cool. Mulch and insulate the pot and soil surface from the sun.

Paul

"If the partcile fizzes when submerged under strong acid you know it has lots of carbonate."

This is EXACTLY the reaction I observed when testing different PH acid solutions in a sample of the Turface from the affected beech.

wow, after 3 years I'm finally learning to water. Isn't that what they always say?

Let me share one other observation with you Paul, I noticed that when I mixed mir-acid at half strength with rain water I got a PH of 6.0
when I mixed the same concentration with my well water from the hose I got a PH of 7.5. Am I correct in thinking that my well water is in fact SO alkaline that it was able to buffer the PH of mir-acid up over the PH threshold at which Many of the nutrients within the fertilizer are accessible to the roots, after a full season of mixing my fertilizer with the alkaline well water no wonder my trees displayed a nutrient deficiency, It seems that not only did the alkaline water effect the media PH, its very nature distorted even the PH of my fertilizer! Does that sound right to you?

If so this is a MAJOR revelation for me!
-Jay

I think your beech leaves' "problems" are a lot simpler than all that.

Senescence.

It has been a bad year climate wise, storms have beat at the trees, it has been hot, and now in the NY area, fall is almost there. Many, Many leaves are simply getting old.

Jim,

This is a problem that started WAY back in early July, It was caused by my inexperience with fertilizer requirements and hard water interaction with completely inorganic media.

Strangely most of the rest of the tree actually looks pretty good. In a funny way I pray for Fall to come and just put this poor Beech to bed for the winter.

Jay,

Regarding the mir-acid question, to be honest I’ve never used the stuff and so had to go and do some homework. Quick search got me a material safety data sheet.

http://www.stancoe.org/scoe/busserv/safety/msds/uploaded/plant%20food,%20miracid.pdf

Which gave fairly general info, another search gave me a site which identifies CAS numbers

http://webbook.nist.gov/chemistry/cas-ser.html

Which provided the main ingredients used in miracid; which are, ammonium dihydrogen phosphate, potassium dihydrogen phosphate, Urea, and potassium chloride.

For the sake of simplicity, we can say that there are no strong acids in mir-acid. It relies on the acidification derived from the nitrification of Urea (there’s 30% N in the product, that’s lots!) by bacteria and the release of H+ during root absorption of ammonium to reduce pH in potting media/soil.

The dihydrogen phosphates are salts of a strong-ish acid ((orthophosphoric acid, H3PO4) it’s not as reactive as hydrochloric or nitric acid, but don’t get it on your fingers!) the first H to be removed goes easily, to form
K H2PO4. The next Hydrogen, to make K2 HPO4, is a little harder to remove, making H2PO4 a weaker acid. This explains why in rain water it gave a slightly acid pH, and why in your well water it had little neutralizing capacity.

As you know, I don’t like miracle gro as a liquid fertilizer for bonsai. Its fine on your garden beds, but on bonsai it’s not so good. Firstly, Urea has to be converted by bacteria to a useable form, either ammonium or nitrate, this process is unpredictable as it depends on availability of carbohydrate for bacteria in the potting mix as to how much they convert. Secondly at temperatures below 16 C/ 60 F the process of converting ammonium to nitrate is inhibited, so if there is plenty of carbohydrate around, there is a chance of ammonium toxicity in the plant, especially during overcast weather. Thirdly, it has potassium chloride in it; that is enough reason in itself. Mir-acid doesn’t contain any nitrate or sulphate, two anions which restrict chloride uptake, so there is high risk of chloride toxicity, which gives the symptoms of marginal leave burn.

Here are some photos of issues I have dealt with over the years and what i'm talking abot as being a plant management problem.



Calcium deficiency


calcium deficiency mature leaf


marginal leaf burn in hornbeam


marginal leaf burn in hornbeam due to Nitrogen toxicity


Leaf damage due to oxygen deiciency in roots

Regards

Paul