On Tue, 14 Jun 2005 20:15:29 GMT, "Alex Woodward"
wrote:

Is there an easy way to turn limey tap water into acidic so that I can water
my heathers.

Alex

I add a teaspoon (say 5 ml) of vinegar to a 7 litre watering-can if
I'm watering ericaceous plants with tap water. It brings the pH down
to about 5. Our tap water is pH 7.5, not because we are in a chalky
area, quite the opposite, but many water companies add lime to raise
the water pH and reduce corrosion of concrete tanks and pipework, and
to assist in clarification of the water. I use vinegar because, as a
weak organic acid (in the chemical sense, not the eco-friendly sense),
it's broadly similar to the acids already present in peaty or acid
soils, but a single drop of battery acid would probably be just as
effective!

Calcium in th water itself isn't harmful to heathers (or other
ericaceous plants, for that matter), but the high pH associated with
chalky soils or limey tap water means that certain trace elements,
notably iron and manganese, are rendered insoluble and unavailable to
the plants. Some plants (and some types of heather, especially the
winter flowering types) are quite happy in these conditions, as they
don't have a high requirement for iron and/or manganese, but most
ericaceous plants do, so their leaves become chlorotic (yellow) and
they fail to flourish. Watering occasionally with limey water probably
won't do any harm, but repeated watering will eventually raise the pH
of the soil, or more particularly compost if it's a potted plant.


--
Chris

E-mail: christopher[dot]hogg[at]virgin[dot]net