"David Hill" wrote in message
Fran wrote "I have water repellent soil due to drought conditions and
am
tempted to use a surfactant to help get water down deep into the soil. "

Why not just use washing up liquid, It is a negative ion wetting agent.

But will detergent kill or harm worms?

My major concern about any sort of wetting agent is wheterh they will do
damage to micro fauna and specifically worms in the soil. I've had no luck
doing a google search and the local gardening gurus in the media don't seem
to be able to answer this question.