In the article ‘A teaspoon of vinegar’, a brief discussion focussed on the differences between rain water predominantly acid and what comes out of the household tap; a chemical cocktail and its effect on bonsai trees and shrubs. Hence it might be prudent to have a brief review of the chemicals found in rain and tap water.
RAIN WATER: having a pH range of 5 to 6 contains many types of nutrients and is free of salts and other harmful elements and although it absorbs atmospheric gases, it remains pure until it comes into contact with the soil. Thus, rain water becomes contaminated due to the chemicals and pollutants that are present. The major causes of this phenomena include factories, power plants, automobiles and low-flying military aircraft the latter a significant contributor to the damage of trees.
Such chemicals that include, sulphur dioxide (SO2) and nitric oxide (NOx) become acids when they enter the air and react with water vapour. The result is sulphuric acid (H2SO4) and nitric acid (HNO3) which, can alter the pH range making it more acidic – a pH range of 3-4 for example. However, some tree species thrive in acidic conditions, Beech, Dogwood, Willow oak, Magnolia, Azalea, Holly, Birch, Pines and Rhododendrons as their soil conditions from where they originate are predominantly ericaceous. (acidic)
TAP WATER: with a pH range of 6.5 to 8.5 (depending on your particular region) contains various chemicals some thought to be beneficial, but series of tests conducted in recent times have cast doubt on this perspective for example. Fluoride (F) in drinking water began back in the 1940’s to assist in reducing tooth decay, but fluoride is a neurotoxin and endocrine disruptor, able to damage the thyroid gland, calcify the pineal gland and interfere with bone formation. The toxicity of fluoride is quite high and because of the risk to health many countries have banned water fluoridation.
Chlorine (CI): is a strong disinfectant added to drinking water as a purification technique, it is a reactive chemical that bonds with water, including the water in the stomach that produces poisonous hydrochloric acid. Excessive exposure to chlorine can cause cell damage and respiratory problems. Nevertheless, water companies continue to use it despite not being completely safe.
Other chemicals found in tap water are mercury (Hg) – a naturally occurring element usually a bi-product of mining and industrial practises. Arsenic (As) is used in a multitude of industrial processes and if improper disposal is not taken care of, environmental contamination is the result.
Lead (Pb) is a major toxin that still exists due to corroded piping systems and is extremely toxic especially to humans. PCBs or polychlorinated biphenyls, are chemicals used for industrial purposes such as insulation, machinery, oil, paints, adhesives, electronics and fluorescent lights. In 1979 PCBs were banned but, they are still found in land-fill sites where they continue to break down and pollute the environment.
In addition, other chemicals found in water supplies include, Perchlorate, (CI04) HCB or Pentachlorophenol (C6) and DDT (C14H9Cl5) (Dichloride-Phenyl-Trichloroethane) and all have detrimental effects to some degree. As do modern insecticides and herbicides including Glyphosate which, are highly toxic and a cause for concern as they break down in the soil and are transported to other areas via rain fall and by the wind.
VINEGAR: is an aqueous solution of acetic acid combined with other trace elements and is the result of a fermentation process using ethanol, various sugars and acetic acid bacteria. Some types of vinegar contain up to 20% acetic acid, but these are strictly for agricultural or cleaning purposes and not intended for human consumption.
Normal vinegar regardless of its colour or flavouring contains 4 to 7% acetic acid and 93 to 96% water and can be used in bonsai to counteract the chemical effects of tap water. The recommended dose to attain a pH range of 5 to 6 is 1 level teaspoon (1 ml) to 7 litres of water. After a period of time, the container will discolour with black streaks and sediment, this is the residue of acetic acid combatting the chemicals as shown below; but keep the container away from children and pets and do not consume.
Soil pH: in nature one can find areas where a variety of species both coniferous and deciduous grow together with some in close proximity and within this area the pH can change. This variation is due to a species leaf shed for example, the ground underneath conifers will be strewn with needles, which break down giving acidity to the soil, thus reducing the pH. Alternatively deciduous leaves decompose allowing the nutrients previously tied up in the leaves to be slowly released back into the soil where they can be reused, hence the pH rises.
There exist many soil types each having their own properties which, can be categorised into 3 sections; ericaceous (acidic) pH 3 to 6, neutral pH 6 to 7.5 and alkaline pH 7.5 to 8.5. Each soil type has their own type of living organisms classed as Acidophiles, Neutrophiles and Alkaliphiles respectively. Such organisms include archaea, bacteria, actinomycetes, fungi, algae, protozoa, and a wide range of insects; mites, nematodes, earthworms and ants. These consume, digest, and cycle nutrients all of which are important to the vitality of a soil composition.
Once the origin of your particular species has been established whether tropical, temperate or northern hemisphere, it is relatively simple to determine the pH range required by the plant. To assist you in this go to the Articles ‘The pH factor’ parts 1& 2 posted in April 2017 where you will find a chart showing the pH range for most bonsai species. In addition, there is a comprehensive description on soils and their composition.
DOES VINEGAR WORK?: in the article ‘The Colourful Maple‘ (September 3, 2017) my A. palmatum amoenum and the red spider mite Tetranychidae urticae was discussed. The plant was brought inside and placed under full spectrum light, but the change in temperature caused the plant to leaf-drop; new buds appeared but would not break into leaf. With the danger of frost over (May) the plant was moved outside where it was subjected to rain fall, in June the buds had broken and by July it was growing vigourously.
After some research, it was concluded that tap water is detrimental to a tree’s health and vitality, since then all my trees are given the vinegar solution; although the dosage is either reduced (half a teaspoon to 7 litres of water) or increased (1 and a half to 7 litres of water) depending on the species.
Further evidence to confirm this perception is with the Abies procera glauca prostrata or ‘Noble Fir’. This conifer requires acidic conditions in order to survive, it cannot tolerate water with a high pH. One of my students has this species and when it was given tap water, the needles turned brown; a sign of ill health. He now uses the vinegar solution.
Rain water is soft with a pH of 5 to 6 – suitable for most plants, if you have the means to collect it then there is no problem, but if not, you have to find a way to make hard tap water soft therefore, the suggestion is ‘A teaspoon of vinegar’ . Until next time, BW, N.