Nick Maclaren wrote:


In article ,
bigboard writes:
|
| I have a diverter on my downpipe that sends all the rain water from the
| roof and waste water from the bathroom to my water butt. I've never had
| any problems using this to water the garden, and despite rumours, I use
| soap regularly!

Soap biodegrades easily, and household detergent isn't much worse.
But you can cause trouble by watering with nothing but soapy
water in dry weather, as the water may evaporate or be used faster
than the bacteria can break down the soap.


The soap does seem to break down to a certain extent in the water butt, but
I have wondered how long it takes. As you say, in long dry spells, the
soapy water won't be diluted by rainwater, but as I only tend to water when
first planting out, this hasn't been a problem for me. I prefer to
encourage deep rooting and getting as much compost in the soil as possible.
All good practice that I'm sure you're well aware of anyway!

As with using alkaline water, a good rule is to flood the area
infrequently. DON'T water little and often with unclean water.

I'm a flood irrigator when I do it at all.



Regards,
Nick Maclaren.

--
"The illegal we do immediately. The unconstitutional takes a bit
longer."
-- Henry Kissinger