Dwayne Reid writes:
> I'm interested because I'm looking after my friends house while they
> are on vacation and they have 3 plants that need watering - two large
> plants (small trees, actually) that stand about 6 feet tall, the
> other is a medium-size pot on the table.
>=20
> I have essentially ZERO gardening experience and don't have the
> faintest idea of how much water to give these plants.  All I know is
> that they start shedding leaves when they get too dry.  Anyway,
> having something that can tell me how moist the soil is would go a
> long way towards me not killing these plants.
	Even the experts say that soil moisture is hard to
measure. Believe it or not, some plants actually produce
ultrasonic noises when they are thirsty. Some researcher in
Canada was recording the noise output and trying to come up with
a better way to save water by only watering when needed.

	The theory about the source of the sound was air bubbles
in the liquid inside the plant. When the plant was dry, the
sounds were more continuous like a scream for water.

	I think this study was done some time in the late
eighties. I have thought of pulling weeds out of our yard, (no
shortage here,) and attaching a piezo disk to them and see if
they die screaming.

Martin WB5AGZ
--=20
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