For humic acid to really do its job a few things need to be present.
First you have to have a soil with low cation exchange.
You have to have large particle sizes.
...and slow and steady for maximum effect.
What constitutes a soil with low cation exchange. Clay! Akadama ranks right up there with one of the lowest cation exchanges known. Why is it good? Because it is Volcanic in origen. During the carboneferous period 350 million years ago when Carbon Dioxide had a huge hold on the earths atmosphere, plants grew to enormous size. as these plant layers were smashed down they created huge beds of humates that today are known as leonardite, or lignate coal (soft coal) as well as oil depostits. Many of these layers were covered over with huge beds of lava that mixed with humates and made the layers we dig up today known as akadama. It is because of this almost organic infusion of clay and humates that makes akadama a soil that is indeed great for bonsai. While I will concede that freeze thaw cycles would be very bad for a soft soil component such as this, for those that can afford it and get it, it is worth the extra price and effort. Your choice.
Particle size is another consideration. Most people in the USA use soil with a small particle size. Soil like haydite, oil dry, ditamatious earth, turface and even akadama is too small for proper air exchange in the roots. Proper soil size should be about 8-10 mm. Even in my shohin I will use about 8 mm soil particle with a top layer on for asthetics. I have actually cut panty hose in the size of the pot and placed 1-2 mm on top for a show only to remove it later. All particles must be sifted as no dust should be in the pot. Humic acid will alter the cation charge of the particles and make them usefull in the attraction of fertlizer ions. Clay type soils and lava will actually repel fertilizer and with fast draining inorganic soils, fertilizers will be simply washed thru. This attraction does not happen over night. This takes a good six months to get the soil holding fertilizer ready for the plant to take up. Trees do not stop growing, they will feed and grow to great proportions if the tree can get nutrients and water in a balanced system. Humic acid just providea the catalyst for this to happen. Humic acid is not a fertilizer and a good fertilizer regimen has to be established in conjunction with the application of humates.
When I started 7 years ago I used straight humic acid as leonardite on top of the soil. My stuff at the time was 85 percent humin acid. I nearly burned up some trees. Now I use a fertilizer enhanced with humic acid at 5 percent bi-weekly, as well as miricle gro shake and feed ( the green pellets in my photo's.). I do not start the humic acid untill April 1, but continue all the way to November. I fertilize year round.
The most noticable effect for me has been better buds in spring, more abundent growth in spring, faster wood production and nearly.....NEARLY no leaf burn of maples all the way thru the year. October is still a hard month for me and just before I start to get leaf color they will burn up and look terrible. Then I get color on burned up leaves.
Slow and steady. Use small amounts more often. If a "little is good more is better" is not the way to go.
Some people use conditioner on their hair and some do not. I have seen healthy hair and what proper hair products can do for a head of great hair. Use humates if you wish, I have seen a difference, but some say it makes no difference. Maybe they just wern't using it correctly. It took me 7 years and a few lost trees to figure out what worked. Everyone will have to experiment on thier own trees due to soil ingredients, particle size availability and watering schedule.
