soil ph ranges

Hello to all could someone tell me how I would change the ph of my soil if it was not correct ?

increase ph use lime decrease use sulphur....do you have a ph testing kit?

No I dont have the testing kit but what source of lime and sulpher ?

Kingbean, you can get a basic soil pH test kit at a decent garden centre. Likewise, you can get soil additives there.

It might be helpful if you told us more specifically the reason(s) for asking the question in the first place though.

Well fiona ive been doing a spot of homework for the coming year about pruning and repotting and I come across trees ph ranges and thought it would be a good idea if I was to check all my potted trees and adjust the ph levels acordingley.

Most of our Bonsai potting media are pH neutral, that is 7. However, a few species such as Azalea, Ixora, Camellia, Gardenia, like a lower pH. There are specific fertilizers for these species that help.

So is it not worth accuratley adjusting each individual trees ph then ?

depends on the tree^^ are your tree's not looking too happy? do they need more nutrients?

pH affects the take up of nutrients by the plant. If a plant has yellowing leaves, and the roots are healthy, and it is getting adequate fertilizer, the problem could be pH.

As I mentioned above, most plants favor a pH near 7.0. A few prefer a lower pH and unless you are growing them you don't need to worry about pH.

kingbean wrote:So is it not worth accuratley adjusting each individual trees ph then ?

No. With the exception of a few plants -- azalea, etc. already mentioned -- that do poorly in anything but quite acidic soil (for which you use Miracid or Azalea fertilizer), our trees will all do well within the middle range of pH.

Thanks all.
All of my trees are doing pretty well I just wanted to know if I was to adjust the ph would it make them even better but now I know its not that Important to make the ph dead accurate.
Thanks again.

Soil pH is a complicated arena.

Soil pH's drift up and down for a variety of reasons. Principally, the quality of your water and the type of fertilizer you use are the main influences on the pH of the potting media.

Generally when pH rises (soil becomes alkali) above pH 6.5 iron will become deficient due to reactions with carbonates and phosphates. Some plants, iron efficient plants, can cope by excreting acids from the root to dissolve these iron complexes, other plants like azalea, cannot, and so become yellow and sickly due to iron deficiency at pH > 6.5.

Phosphorous, manganese and boron also become unavailable to plants as pH rises above 6.5.

At the other end of the spectrum, magnesium becomes deficient and pH below 5.5. Manganese may become toxic at pH of 5.0 or lower.

Thus it is recommended to keep trees between 6.0 and 6.5 for optimum growth. It has been recomended by some that J maples should be between 5.5 and 6.5

pH changes due to different things. Using nitrates (NO3) as the main source of nitrogen can cause an increase in pH over time because plant roots release bicarbonate into the soil to balance electrical charges in the root cells. Ammonium will cause a decrease in pH because roots excrete hydronium (H+) ions into the potting media. Bicarbonate in irrigation water also causes a rise in pH over time. Insufficient phosphate and nitrogen nutrients in the media also cause a rapid drop in pH as roots excrete acid to try and release bound nutrients form the soil.

Organic fertilizers are different as they really on bacteria to convert organic N to mineral N. This process is temperature dependent, nd so it is possible for plants to be nitrogen deficient one week, and then suddenly be over fed the next.

Personall I check the pH of my soils only when I suspect a tree is suffering a nutrient defficeny. It is also a good idea to grow pelagonium, and petunia's (or azalea) amongst your bonsai. Pelagonium are iron efficient plants and do not tolerate low pH, while petunia are iron inefficient plants and don't like high pH. If your pH's are drifting these plants will show you which direction they are going.

There are different ways to change the pH. Iron sulphate will acidify the soil, lime, dolamite will raise it. These are the safest ways.

Reagrds

Paul

Thanks Paul that was very interesting and helpful.

There are different ways to change the pH. Iron sulphate will acidify
the soil, lime, dolamite will raise it. These are the safest ways.

And they are all very temporary. Luckily, if you fertilize your bonsai regularly you have less problem getting a somewhat acide (or at least neutral) soil. And again fortunately, there aren't mant bonsai that need alkaline soils.

95% of the trees we use will do just fine in a neutral pH.

"Luckily, if you fertilize your bonsai regularly you have less problem getting a somewhat acide (or at least neutral) soil. "


You have kind of missed the point.

It is the fertilizer (or lack of), water quality, and the plants response to these, which affects pH over time.

It is very possible to have adequate nutrients in the soil; but because pH has drifted either up or down a nutrient becomes unavailable. Adding more fertilizer won't fix the deficiency, nor will it adjust the pH. Only specific reagents, such as dolamite, iron sulphate etc, or changing the type of fertilizer, will bring about an adequate change in the pH

All amendments to potting mixes, whether iron sulphate, or dolamite, or fertiliser are temporary. There is not permanent fix for anything in potting media. Which is why it's a good idea to have simple ways of telling if there is a problem. The biggest problem with testing pH is you have to remove some of the potting mix, preferably from about halfway down the pot. As you know this is fairly disruptive to the plants, and why I don't test pH all that often. If you can grow healthy pelagoniums and petunias in the same potting mix with the same fertiliser regime, then you have a simple pH test right there.

The point off all this is being aware that irrigation and fertilizer choice can affect pH and that it is wise to check pH if you notice a nutrient deficiency in your plants, rather than just adding more fert.

Paul

Good info, Paul. Thanks!

Thanks very much paul im going to try growing some pelagoniums and petunias,
Thanks.

Hi Kingbean,

I suggest zonal pelargonium, as they last for more than one season. Some cultivars have exceptionally pretty blooms as well, which is a nice addition to the bonsai benches.

Paul

Ok cheers paul.