How do we acidify inorganic Bonsai soil?

Paul

Knowing now that its the release of H+ by the plant in reaction to the ammonium by product of microbial action on Urea, Being how products like Mir-acid work;
How do you think our Urea free fertilizers (with 8%Ammoniacal Nitrogen and 12%Nitrate as their nitrogen source for example) will fare when used with plants like Azalea. I know My Bougainvillea's have a low pH preference and they seem to love the Urea free.

how Would the 8%NH4:12%NH3 effect soil water pH? Assuming de-ionized irrigation water is used to keep things simple. I'm wondering how my Urea free fertilizers will do with Maples, Azalea, Beeches..etc this upcoming summer as I have yet to try them on my deciduous trees.

Always glad to have you answering and educating us!

-Jay

Thanks to everyone contributing for such a great discussion. The complexity is high but it explains many things I have wondered about over the years. Water issues and plant nutrition are fascinating to me.

This is excelent - but with hindesight I'm wondering if we are getting a little too westernised with the thinking and missing some undeniable result driven facts..

Basically a vast majority of the finest OLD bonsai reside in a number of japanese nurseries, and have done so for many decades, passing from generation to generation. When we see them at shows, calenders, in apprentice books and blogs etc they are in perfect health and awesome condition - the bark gets more aged and the foliage remains fresh. The trees are basically potted in a combination of akadama, kiryu, kanuma, long grain moss and river sand - the ratios being changed for the tree species. The feeding from that point (we are lead to believe) is very similar recipe cakes for most trees, just the amounts, timing and frequency are varied. In Cornwall we get periods of high rainfall at times so I use additional chealated iron as a soil additive, and do soak the one azaelia in a miracid bath 2 or 3 times a year.

This suggests 2 avenues - adapt the actual soil to the trees' needs and feed a balanced fertilizer, or stick to a soil made from one single neutral composite and continually acidify with added products. The test of time is a great decider - at the moment one method is undeniably proven and one is in its infancy. My personal path as several know is to rely on 'traditional' japanese soil components and I see superb mychorrhizal fungi growth throughout many pots (this is what really keeps the trees in perfect health afterall, not the fertilizer). I will watch with interest the single soil users to see if they get various species of this fungi colonise the potting medium as this is a major key to keeping mature bonsai.

Great thread, one to remember for the future for sure, but I feel the need to take one step back and ask yourself why you actually want to use a single component soil in the first place needs answering before worrying about the added complication of acidifying it.

cheers, its threads like this that make ibc top of the pile for me.

Marcus

I think a lot of the reason the Japanese use the soil they do is because modern substrates are just that...Modern. Tradition is a strong cultural influence for the Japanese. The prevalence of organic fertilizers in Japanese Bonsai would also require organic matter in the bonsai mix, I believe it helps foster the soil bacteria that make the organic fertilizers available to the plant through metabolic action. I note in Peter Adams book his mention several times of the soil mix used at Fukukaen of Nagoya containing 1/3 organic. He himself recomends 40-60% for Maples

With increasingly efficient modern synthetic fertilizers the option to use a purely inorganic media becomes available, due to the soil microbial activity being unnecessary for modern fertilizers like my Urea Free and chelated minors. I switched after getting Verticilium wilt on a maple I liked quite a bit, as I was able to reasonably pinpoint the source of the oospore as being the pine bark I was sifting from soil bags. I then started reading about and indeed contacted Harry Harrington about his great success with pure inorganics.

Since then whatever I have been planted in 100% Turface has just exploded! Far out growing other plants that still remain in my old mix. Its difficult to over water, its difficult to over fertilize, the medium cannot compact or break down, and issues like root rots become almost moot. The soil aeration and resulting root activity is phenomenal. It also makes re-potting time so much easier. These mediums have been known to horticulturalists and time tested in hydro-and aeroponic gardening for decades, it is perhaps only the weight of tradition that has kept them out of Bonsai culture for so long.

Mychorrhizal fungal activity and its necessity for plants is still being investigated. Some feel with fertilizers that are very efficient at delivering their nutriment, the fungal activity becomes much less important, and that explanation certainly appeals to my common sense.

The choice of soil and fertilizer go hand in hand in my opinion. A change in one may, or may not, require altering the other and vise versa..

But Marcus after seeing your trees and especially your Kaho Azalea I say 'If you have a system that has worked that well for you, don't change it..'

This thread and the 'help with beech leaves' thread have taught me more about Bonsai than anything else on IBC yet!!
-Jay

I don't want to turn this into a debate or argument about which approach is "right" or better. Valid arguments can be made for both. I will say, however, that it should be kept in mind that the techniques developed over the years in Japan may not translate directly to other locations for a variety of reasons...climate and water quality being the primary ones. My other concern would be the reliance on materials that must be shipped from halfway around the world. Besides cost, what do you do if that supply runs out or becomes difficult to obtain?

The main benefit I see to this discussion is that it gives individuals the information required to make informed decisions for themselves. For example, the often repeated suggestions to "fertilize with miracid" (or other "acid" fertilizer), or "apply extra trace elements" may not always work as expected, depending on the soil components and water quality being used. Understanding the information being discussed here can help one figure out how to proceed when the usual methods don't succeed.

At least, I hope that's the case! I know I've been dealing with problems with a few plants the past couple of years...we'll see if this info helps me figure out what I'm doing wrong...

Thumbs up for this thread and I love the last three posts for maintaining a great tone and feel while making valid and key points to the discussion.

Jesse wrote: I love the last three posts for maintaining a great tone and feel while making valid and key points to the discussion.

Its only natural as I have great respect for the members on either side of my most recent post, the search for knowledge is always made easier with humility.

How do you think our Urea free fertilizers (with 8%Ammoniacal Nitrogen and 12%Nitrate as their nitrogen source for example) will fare when used with plants like Azalea.

I use a urea free chemical fertilizer that I blend myself to feed azalea, japanese maple, J. Beech. They seem to do very well with it.Urea is not a natural planyt food, sure its excreted by mammals all around the world, but its very quickly broken down to ammonium by bacteria, plants in the wild never feed off the stuff.

how Would the 8%NH4:12%NH3 effect soil water pH? Assuming de-ionized irrigation water is used to keep things simple. I'm wondering how my Urea free fertilizers will do with Maples, Azalea, Beeches..etc this upcoming summer as I have yet to try them on my deciduous trees

Regarding soil pH and your fertilizer, it’s hard to predict where it will go. You will just have to watch your plants and see what happens. Japanese maples are a good test plant to have though, as elevated pH really affects their leaves. Beech just stop growing and azaleas go yellow. Just keep a close eye on them. Test the soil pH after 3 weeks or so, if you like, to see if it’s drifting. But visual inspection of your plants is a good option. I don’t like digging about their roots too much, maybe once or twice to just confirm a suspicion.

Two most important aspects of fertilizing with chemical fert for these kinds of trees is to keep the EC low, around 700-1000 micro seimens/cm. The other is not to feed them until about 3-4 weeks after they bud out. I suspect maples (maybe beech) are very susceptible to ammonium toxicity early in spring, certainly the Japanese practice this approach.

I also believe that a lot of leaf damage we see in summer and call windburn is a result of poor feeding in spring when leaves are developing. If something nutritional is not available (or excessive), or imbalanced, as the leaf is developing, then the quality of the leaf suffers and has less resistance to summer stresses. I’ve seen this happen this year with maple leaves that grew when soil pH was too high, these leaves showed much lower tolerance to diseases, sun scorch and marginal leaf burn etc, leaves that grew once pH was returned to normal were much more tolerant. Just my observations, so take it with a grain of salt. The thing for me to do now is to show there is some reality to the observation.

Regarding the Japanese and there horticultural practices. I personally believe we have a lot to learn from the Japanese on looking after plants, I’m certainly not saying we should not listen to them. All I have been talking about is plant physiology, how you feed the plants is up to you. Bear in mind that every person doing bonsai will have a preference for a fertilizer and a soil that suites them, and may not suite others. If what you are doing works for you then great, keep at it.

I think fertilizer balls are an excellent way to feed plants, I’m a firm believer that continuous feeding with frequent flushing of the root ball is the way to maintain healthy, vigorous growth. I only use chemical fertilizer as it is cheap and convenient. But I have no problems with organic mixes or fertilizer balls. I also think the way Japanese feed is important as well, in that they feed a little in spring, a little bit more in summer, and more in autumn. I’ve recently been reading about how deciduous trees store nitrate in their roots during autumn for spring growth, and recent home research has shown to me that trident maples do not need any fertilizer in the first three or four weeks of growth. Last year I fed my trees with nitrate up until they dropped their leaves and I was impressed with the number of dormant buds that developed into shoots this year. I don’t think plants care how they get their nutrients, just that they are there, it it seems important that nitrate be present in autumn. This is of course, the complete opposite to what many say should be done. Apparently this is what deciduous trees do, they store nitrate over winter for spring growth. WHY? Probably because ground temps are too low for nitrification in spring. The only N available is ammonium. Ammonium requires plant carbohydrates to de-toxicify it when it is taken up ( and at a time when plant carbohydrates may be depleted). If plants store nitrate over winter (taking it up in autumn when it’s plentiful) they don’t have to take up any N in spring, they can get leaves out and be producing carbohydrates, ready for when they do require soil ammonium. This is why I say don’t fertilize maples in the first three weeks of growth in spring.

The important thing for plants is that ALL elements needed for growth are present, and not many fertilizers supply them all.

As for substrates, they must provide appropriate levels of oxygen to the roots, water holding capacity is important, but it is the air filled porosity that is critical for good plant growth, and disease resistance. What they are made of is important, but particle size is probably most important. I think having your soil near a pH that is good for growth is a good policy. Especially for any plant that is not going to be fertilized for a while, pH will only change when plants are taking up nutrients, water may push it up if it has some alkalinity, but repotted plants that are not being fertilized will recover better if the new soil mix is at the appropriate pH.

Potting mix contaminated with disease is a big problem everywhere, an article in the Australian IPPS newsletter by a manager of a company that produces a large proportion of potting mix here, clearly states that pythium phytophthora, fusarium and other major plant pathogens are all endemic in potting mixes. Nearly all these fungi need low oxygen levels to gain access to plant roots. If you can maintain high air filled porosity then soil borne diseases shouldn’t be a problem, of course this means repotting at the appropriate time, keeping pots elevated to maintain excellent air flow, etc etc

This suggests 2 avenues - adapt the actual soil to the trees' needs and feed a balanced fertilizer, or stick to a soil made from one single neutral composite and continually acidify with added products.

Its not the soil that changes the soil pH, its the plant, the fertiliser an the irrigation water combined together. If the fertiliser has no ammonium and all nitrate then the soil pH will drift up, no matter what its composition, no matter what the source of the nitrate, whether organic or mineral. Organic fertilisers have less problems because most of the N is in organic complexes, there is a natural buffering effect, but it can still cause pH's to drift, or may not provide enough acidity to counter water alkalinity, if there is any.

Also, the Japanese still have their problems with plant health. There are many articles in Bonsai Today dealing with sick and unhealthy trees, root rot, salinity etc. I’m not sure how you adapt a soil to the trees needs in a pot. This is an ongoing problem, and even the Japanese have changed their soil usage over the years. Old bonsai books from the sixties suggested a certain type of ground soil was best for bonsai, now it is all akadama and kunama. What I suggest is doing simple pot trials in your own yard to see what works best for your trees in your environment.

What’s a balanced fertilizer? Would the same fertilizer be suitable to use on a JBP and a J maple?

I use only chemical fertilizer, some of my pines have a lot of mycorrhiza, others hardly have any, I can’t tell which trees have mycorrhiza from those that haven’t without looking at the root ball. Some scientific research shows there are benefits in early germination, higher germination rates, earlier recovery from transplanting, higher tolerance to drought; with using mycorrhiza. What seems to be very important is getting the right type of fungi for that particular species of plant.

I seem to have rambled on a bit here, so I'm going to call it a night. I’m really enjoying this discussion. There is so much to learn about how plants grow and we are only scratching the surface. And to think, science really only knows 3/5’s of bugger all about how they work anyway. We still don’t know how they take up magnesium!

Regards

Paul

What you may have gathered from all this is that if you have acid or alkaline soil, it tends to want to stay that way. Attempts to change it are fairly short lived.

It's not hard to find plants that thrive on neutral to acid soils, but there are plants that do well in alkaline soils, too. Here's a list to help you just live with it, derived from several I'net sources:

Here are some of the garden plants that prefer alkaline soil:

Evergreen shrubs
Green Velvet boxwood - Buxus ‘Green Velvet’ -- a cross between B. semipervirens and B microphylla; (Zones 6–8)
Daphniphyllum himalaense ssp. macropodum (Zones 7–8)
Photinia species (Zones 7–9)
Aucuba species (Zones 7–10)
Euonymus fortunei ‘Emerald Gaity’, ‘Silver Queen’, ‘Emerald n Gold’ (Zones 5–8)
California lilacs (Ceanothus spp.; generally Zones 8–10)

Deciduous shrubs
Daphne species (Zones 5–8)
Deutzia spp. (generally Zones 6–8)
Forsythia spp. (generally Zones 6–9)
Mock oranges (Philadelphus spp.; generally zones 5–9)
Lilacs (Syringa spp.; generally Zones 5–9)
Weigela spp. (generally Zones 5–9)
Spiraea spp. (Zones 3–8)

Perennials
Hellebores (Zones 4–8)
Pinks (Dianthus spp.; generally Zones 4–10)
Brunnera macrophylla ‘Jack Frost’ and ‘Looking Glass’ (Zones 4–8)
Clematis spp. (generally Zones 3–8)
Potentilla spp. (generally Zones 5–8)
Scabiosa spp. (generally Zones 5–9)

Trees
A tree is a woody plant with a main trunk and often a distinctive crown. Trees are also perennial, in that they survive longer than two years. The following trees thrive in alkaline soil:
Cedar elm (Ulmus crassifolia)
Holly/Holm oak (Quercus ilex)
Olive tree (Olea europaea)
Japanese plum (Eriobotrya japonica)
Asian persimmon (Diospyros kaki)

Shrubs
Shrubs are plants with woody stems but with relatively low overall height. Like trees, shrubs are also perennial. Many types of shrubs grow well in alkaline soil, including:
Japanese quince (Chaenomeles japonica)
Littleleaf boxwood (Buxus microphylla)
Feathery cassia (Cassia artemisioides)
Daphniphyllum (Daphniphyllum humile)
Silverthorn (Elaeagnus pungens)
Heather (Erica melanthera)
Cassina (Ilex vomitoria)
Lavender (Lavandula officinalis)

Vines
A vine is a plant with weak stems that supports itself by creeping, climbing or twining along a surface. The following vines thrive in alkaline soil:
Japanese honeysuckle (Lonicera halliana)
Chilean jasmine (Mandevilla suaveolens)
Bluebell creeper (Sollya heterophylla)
Common bean (Phaseolus)

Herbs
Herbaceous plants, more commonly known as "herbs," are plants with non-wood stems that die back into the ground each winter. Herbs can be annual, biennial or perennial. Several types of herbs need alkaline soil to grow, including:
Persian rockcress (Aethionema cordifolium)
Japanese anemone (Anemone japonica)
Kenilworth ivy (Cymbalaria muralis)
Baby's Breath (Gypsophila elegans)
Goldencup/Mexican Tulip Poppy (Hunnemannia fumariifolia)
Sweet Pea (Lathyrus odoratus)


There likely are others.

coh wrote: My other concern would be the reliance on materials that must be shipped from halfway around the world.

Hi Coh, there will be no arguments on a thread as good as this as everyone is adding their varied experiences and actual observations into the mixing pot to share knowledge. To be fair 'airmile reduction' just doesnt work with a hobby like bonsai though - it is a hobby relying on lots of goods being transported around the world as an awefull amount of the trees come from china, japan, taiwan, singapore etc, so do all the tools and accessories, lots of fertilizer, books, soils etc. (To participate in this hobby we all create airmiles and/or sea/road miles for our own personal pleasure).

you may find the climates across the United States are requiring a new approach to pot soils as the land mass is so huge, but I know a significant percentage of the good trees in the Uk are in soils with a lot of japanese components so something is working well in our climate. I did ask earlier what this stuff you guys are using is sold as in the Uk but not seen an answer yet - its not a cat litter type product is it ? as that gets very mixed results here - young trees and basic material seems ok in it but a lot of better trees seemed to loose vigour and refinement. I found on two trees that came to me in it the root pads were weak and poor after a further year on my benches so something wasnt working right for me.

I cant see that cost makes any relevant difference - in the UK the average soil ingredient cost is basically £1 per liter - a few components are a little cheaper but calling it £1 is close enough. 80% of my trees will remain in the pot for 5-10 years and a repot on most of them uses between 5 - 10 litres of displaced soil at most. The tree values are 100's of times the soil costs, and these days i sieve out the used soil and use it for normal garden container potting, then it goes on the borders so is returned to mother earth anyway so i'm only borrowing it really.

I personally think world trade is a good thing, it shares culture, experiences and keeps many countries, businesses and individuals solvent - shipping and delivery is just one small part of this essential network and I would say every one of us should go out of our way to buy from other countries to keep the flow of global wealth circulating. (especially coral and tropical marine fish feeds, bait for carp fishing and quite soon a range of modern organic fertilisers !!!! haha )

Hi again Jay - I applaud the thread and the incredibly knowledgable posts that are turning it into a real gem. Cheers on the kaho - it does seem to like me but one critical observation I have made over the years with azaleas is the micro fine roots seem happier penetrating the soil medium rather than growing around the particles so i think kanuma has an additional property that helps build the perfect root pad hence adding it to my acer mixes this season as an experiment. Re kaho - This year I have removed about 2/3 of the flower buds already as this is repot year and the tree mustn't be allowed to flower quite that strongly when it needs a proper root pruning.

You sound like you are getting excelent results Jay which is great, a lot of people will benefit massively from the soil change, and i think a lot more is going to be learnt about fertilizing over the next few seasons - and the real skills and learning will come from perfecting fertilising to slow and refine the growth on maturing trees rather than pushing it hard on developing ones. Good times ahead i think

cheers everyone

Marcus

just had a little play about to satisfy my curiosity

Marcus

The idea of Azalea wanting to "push" its roots into a medium has me further considering chopped sphagnum in the mix. All the re-pots so far this year including that Crenata are receiving sphagnum.

Interesting to note the akadama's pH in your test is the same as Turface which is what I use primarily its a high fired ceramic clay. Harry Harrington uses Tescos Low Dust Lightweight cat litter and seemingly has great results, it would seem to be another high fired clay product. I do believe there are a lot of unsuitable cat litters but Thats the one he uses for what its worth. I believe you folks have a product called seramis which is similar to my Turface.

My Azalea will have its re-pot next year, I have to let it flower so Russell can tell me its not a Kirume.
-Jay

If you want soil ph to be more basic ( alkline) all you have to do is go the way of Pa..

Just ad lime stone. takes the acid right out of everything and drops the ph... all water here for a result is not neutral... so i have to give the acid lovers more acid then what you would.

marcus watts wrote:I did ask earlier what this stuff you guys are using is sold as in the Uk but not seen an answer yet - its not a cat litter type product is it ? as that gets very mixed results here - young trees and basic material seems ok in it but a lot of better trees seemed to loose vigour and refinement. I found on two trees that came to me in it the root pads were weak and poor after a further year on my benches so something wasnt working right for me.

Marcus,

I've read on various forums about some types of "cat litter" that are available in Europe - supposedly they are fired clay products very much like the turface that we are using (see the reference Jay made to Harry Harrington), i.e. very hard, absorbent material that holds up well to freezing. But since I haven't seen these materials, I can't do a direct comparison. I've never seen a "cat litter" here in the U.S. that seems suitable. However, I'm aware of at least one well known/successful growers who has been using primarily turface (with a small amount of granite grit and peat) for many years with great results, so it can work...maybe not for all trees (azaleas, perhaps?).