All the species we aim to keep have a ph band where the plant has evolved to survive, grow strongly and remain healthy. Along with climatic requirements this is the main reason we don't see every species in the wild all growing side by side.........but as bonsai growers of course we want the greatest variety of species in our collections, or in our sales stock, so the challenges are there to try and keep everything in top health. Soil ph will be governed initially by the soil components you use but it is the water you use regularly that will end up dictating the ph in the pot, so even if you have put an azalea in Kanuma soil (ph 5 to 5.5) it does not mean the condition will remain this way long term if the daily watering is neutral to alkaline.
The rain water butts are long emptied and we are relying on our tap water supplies and hose pipes......who actually has a clue what is coming out the end?........when I do club talks often people will say "I only use rainwater, so I'm fine "..... But rain can be acid, neutral (ph 7) or even alkaline so rainwater is equally as random as tap water in my book. We were relying on tap water twice a day this summer and I felt a few trees were the wrong green........guessing the reason is pointless, how long is a piece of string ?
There we go...........my outside tap water after filling a 200liter barrel ! Water alkaline enough to slowly kill satsuma azaleas, to weaken pines and to make many deciduous trees pale. (Some wild collected junipers come from areas of limestone deposits so they could carry on ok) . You could never guess our tap water was so alkaline as we have absolutely no lime scale deposits in kettles, around taps etc - the meter was calibrated twice, tested on known solutions etc as I could not believe the reading initially.
What clues to we get ?
Use your eyes as the trees indicate if they are thriving or not. Foliage colour is the biggest clue, paler or 'brighter' green on a tree that should be deep dark green is the first pointer. A tree that doesn't seem to respond to fertiliser the way it should is another fairly obvious clue as a tree in a wrong ph environment will struggle with nutrient uptake. Another pointer to something amiss is a tree that has been perfect with a previous owner that does into decline soon after you get it. A shock change from one water quality to another will often make a bonsai unhappy.
2ml of horticultural high quality acid and the 200 litres are now ph5.9, Perfect for the trees here.
Watering is now all done by can of course ! But it is a more controllable way to water and certainly leads to better observation. There is always the option to add a pumped hose set up to the barrel in the future too.
3 weeks in and the pine and yew needles are getting darker green, so are the beech leaves. A common juniper is now a deeper blue green rather than the bright green so the trees are slowly responding. As a tree settles into it's preferred conditions it will grow and respond to our methods and tactics far more predictably, but without measuring the basics how can anyone guess or even advise a grower on their trees?