permaculture

[Toby Hemenway <hemenway@jeffnet.org>]

On 5/9/04 4:22 PM, "Robyn Francis" <erda@nor.com.au> wrote:

> [Epsom salts are] also an excellent natural fungicide for powdery mildew,
black spot etc
> generally applied by dissolving 1 teaspoon of epsom salts in 2 gallons (9
> litres) of water.

And there's a useful puzzle piece. If at that dilution it's still a potent
fungicide, that would suggest my friend Anne would want to dilute it a great
deal below that concentration before putting it on the soil, or it will kill
soil biota. Maybe to 1 tsp in 10 gallons or so. That's going to be pretty
dilute and will use many gallons of good clean water, since foot baths are 2
cups (96 tsp) or so per gallon. Maybe down the drain is the best place,
where it can be diluted with dirty rather than clean water.

The numbers confuse me a bit though, since Mollison states (DM p197) that
Epsom salts can be applied to soil at 45g/m2, or about 15 tsp per square
yard, which seems like it should be harmful to soil biota, even if the
plants will like it.

Toby
www.patternliteracy.com