Tuesday, September 2, 2008

Is your town water killing your plants?

Last year I wanted to start growing various berries and I put in a selection of raspberries, loganberries and hybrid blackberries. Only the blackberries made it, and they didn't do too well, either, although they are still clinging on to life and are making a come-back. The raspberries died after a while without ever making any progress, even though they are supposed to be really hardy and do well in our climate. I thought I had done it all right - the right kind of preparation, well mulched soil, I had put in all the infrastructure, and quite frankly, I was very disappointed and couldn't quite work out what had gone wrong.

I think I now know the answer. Many berries like slightly acidic soil, which I had catered for. However, I had been watering them with town water.

What I did not know and only learnt today: our town water is not pH neutral but has a pH value of around 8.5. That makes it quite alkaline. Watering with alkaline water is bad for your soil and can severely affect your plants.

As the table above (quoted from Virtual Chembook, Elmhurst College) shows, a pH value of between eight and nine is equivalent to baking soda and sea water. Normal range of rain water is around five or six, stream water ranges from six to seven.

I killed my raspberries with town water!

I have planted new raspberries this week. Unfortunately, I have already watered them with town water once before I realised that his was not a good idea. Luckily we do have rainwater tanks, and after the winter rains, there is some water in them. As much as possible, there will be only tank water in the garden from now on!

The lesson from this - find out from your local Council (or a knowledgeable friend!) what pH your water supply is before you use it on the garden.