Hi, My soil is mostly 4.6 - 5 pH. Here and there there are pockets of less acidity, I've measured 6.4. In these pockets there are probably other soil modifications: since this was a farm it could mean anything from a buried cow to chemical waste to old farm implements. (In one area I excavated I found everything from syringes to plastic high heels from the 50s to 17th century coins to an intact copper calvados still!) Anyway the maples generally don't like the higher pH places much. Collected rain water is pH 6.4, but tap water is 7.4! Is this going to make a problem for calcifuge maples? I haven't measured the well yet but I'm guessing it will be below 6; how about that as a problem? Thanks for the help. -E
Emery, How can you tell?, chlorosis? What is the 'ideal' pH for maples? This is something that I have often wondered. The best discussion I have found is in James Harris book, he states: 'all maples will grow in acid soil, but not all will grow on alkaline soils'. The thumb rule is that maples from Japan and North America prefer acid soils and maples from China and Europe can be grown in either acid or alkaline soils. He states that A. palmatum and its cultivars do well on acid soils as on alkaline soils. Now to your question on the water, the answer is probably not. To explain it, let us review a few basic concepts. First, pH is a measure of the concentration of hydrogen ions (H+), and that the scale is logarithmic; that is, at pH 7 there is 10 times as much H+ as at pH 8, and that at pH 7 there is 100 times as much H+ as at pH 9. Second, to change the pH of soil one needs to know its buffering capacity which, in simple terms, represents its ability to resist changes such as pH modification. The amount of clay and/or organic matter in a soil will determine its buffering capacity. The more clay and/or organic matter a soil has, the greater its buffering capacity and the more, say, limestone or sulfur will be needed to effect a pH change. Another important fact is that the pH resulting from two solutions being mixed together is not just an average of the two solutions' pH values, but is also determined by the buffering power of the solutions. So in your case you are mixing water with pH of 7.4 with basically no buffering power with clay soil of pH 5 with strong buffering capacity; hence my guess that, under normal watering where you live, the soil pH will be very little affected. Gomero
Thanks Gomero. Yes, chlorosis indeed. Although I'm familiar with the logarithmic nature of the scale, I hadn't thought about the buffering aspect: interesting. So if any problems are likely, they would show up in pots more easily. -E
First, I had to look up chloloris. According to wikipedia... Emery, are your plants still displaying chlorosis? What measures have you tried and with what success? And to all, while reading the discussion at http://www.botanicalgarden.ubc.ca/forums/showthread.php?t=51820 regarding Taimin nishiki and Izu no odoriko I wonder if anyone has investigated giving these cultivars "exogenous sucrose." What about when helping a stressed tree to recover? I know we give saline/sugar drips to people and animals before/after surgery/trauma. What about plants? In other words, is sugar water ever used as a supplement with JM's?
