A friend of mine is using an old microwave to sterilise soil before
using for cuttings/seeds etc. in his greenhouse.

Is it worth doing?

Will it kill off "good things" as well as bad?

Any comments?

On 03/09/18 14:23, Judith in England wrote:
A friend of mine is using an old microwave to sterilise soil before
using for cuttings/seeds etc. in his greenhouse.

Is it worth doing?

Will it kill off "good things" as well as bad?

Any comments?

I've never bothered cleaning old pots, let alone sterilising them. I
suppose I've lost some seedlings through one pathogen or other, but
really I doubt it's made much difference. If some seedlings have a
propensity to damp off, I doubt clean pots will make a difference, as
most of these pathogens are air-borne. And if you seal the propagator
aren't you creating the perfect conditions for damping off?

And why use soil for cuttings? In general, you use
peat/sand/vermiculite/perlite/commercial compost, etc. The only time I'd
"use" soil is taking cuttings from rose prunings. etc which are stuck
straight in the soil in a slit trench. No sterilisation there!

--

Jeff

Chris Hogg wrote:

I didn't see the OP, but the only time I've sterilised compost is when
I've used compost from my compost heap, which was a cold heap and full
of weed seeds. Cooking it up in a microwave stopped them germinating,
and I'd be reasonably sure that the only things coming up were what
I'd sown. Likewise, cuttings didn't get swamped by weed seedlings.

My dad had a method of soil sterilisation, when he was mixing
potting compost:

He used a wooden box, probably an old packing case, inserted a
metal plate at each end and filled it with soil. The plates were
connected to the mains, via an ammeter. Then he added water
until the soil resistance lowered, and hence the ammeter reading
rose to the desired level. It was left to simmer for hours. I can
smell it now.

I have even found an old gardening book of his in which this
method is explained.

Do not try this at home! ;-)

Chris
--
Chris J Dixon Nottingham UK


Plant amazing Acers.

On 03/09/2018 14:23, Judith in England wrote:
A friend of mine is using an old microwave to sterilise soil before
using for cuttings/seeds etc. in his greenhouse.

Is it worth doing?

Will it kill off "good things" as well as bad?

Any comments?

Steralising soil should do just that STERALISE it, that means killing
off every living thing in it as well as dormant life forms.
I have used a microwave to steralise soil to add to potting compost and
it works well as long as you let it cook and remember to cover the top
so the cooking is even.
You can't cook all that much in a batch but you can do it quite quickly
and a microwave isn't that expensive to run.
But do it in an outbuilding and not in the kitchen, not everyone likes
the smell of steralised soil.
As for the reason to steralise soil. You use it in a compost miz to make
a compost similar to the old John Innes composts - a mix of soil, sharp
sand or crushed grit and peat.

On Mon, 3 Sep 2018 13:23:46 +0000 (UTC), Judith in England
wrote:

A friend of mine is using an old microwave to sterilise soil before
using for cuttings/seeds etc. in his greenhouse.

Is it worth doing?

Will it kill off "good things" as well as bad?

Any comments?


Why thank you : Judith in England


You really are rather sad.

In article , jmsmith2011
@hotmail.co.uk says...

On Mon, 3 Sep 2018 13:23:46 +0000 (UTC), Judith in England
wrote:

A friend of mine is using an old microwave to sterilise soil before
using for cuttings/seeds etc. in his greenhouse.

Is it worth doing?

Will it kill off "good things" as well as bad?

Any comments?


Why thank you : Judith in England


You really are rather sad.

Three replies not enough for you?

Janet.

Chris J Dixon wrote:
Chris Hogg wrote:

I didn't see the OP, but the only time I've sterilised compost is when
I've used compost from my compost heap, which was a cold heap and full
of weed seeds. Cooking it up in a microwave stopped them germinating,
and I'd be reasonably sure that the only things coming up were what
I'd sown. Likewise, cuttings didn't get swamped by weed seedlings.

My dad had a method of soil sterilisation, when he was mixing
potting compost:

He used a wooden box, probably an old packing case, inserted a
metal plate at each end and filled it with soil. The plates were
connected to the mains, via an ammeter. Then he added water
until the soil resistance lowered, and hence the ammeter reading
rose to the desired level. It was left to simmer for hours. I can
smell it now.

I have even found an old gardening book of his in which this
method is explained.

Do not try this at home! ;-)

Chris

Why? He did.

FMurtz wrote:

Chris J Dixon wrote:

My dad had a method of soil sterilisation, when he was mixing
potting compost:

He used a wooden box, probably an old packing case, inserted a
metal plate at each end and filled it with soil. The plates were
connected to the mains, via an ammeter. Then he added water
until the soil resistance lowered, and hence the ammeter reading
rose to the desired level. It was left to simmer for hours. I can
smell it now.

I have even found an old gardening book of his in which this
method is explained.

Do not try this at home! ;-)

Why? He did.

And we all survived. However, we live in different times and
there are those whose understanding of self-preservation could at
best be described as "compromised".

We have moved on from the era when you could light a coal fire
with a gas poker, connected by simply pushing a rubber tube over
an outlet pipe. A new bayonet fitting eventually replaced it.

Remember the Mammod steam engine with a neat little burner for
meths. I can still smell the distinctive aroma.

Electric heaters with very little protection for the elements.

It was once (may still be) possible to buy replacement coiled
elements for such radiant fires. You simply removed the failed
one, used a piece of string to measure the length and stretched
the new one to suit.

My dad told me that in his college days (1930s) they heated a
room by simply suspending such an element from the mantelpiece.

Chris
--
Chris J Dixon Nottingham UK


Plant amazing Acers.

On 07/09/2018 10:14, Chris J Dixon wrote:


My dad told me that in his college days (1930s) they heated a
room by simply suspending such an element from the mantelpiece.

Probably plugged into the single light pendant via a Y adapter so that
you could have the light and fire/iron on at the same time.


--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

On Fri, 07 Sep 2018 10:14:37 +0100, Chris J Dixon wrote:

FMurtz wrote:

Chris J Dixon wrote:

My dad had a method of soil sterilisation, when he was mixing potting
compost:

He used a wooden box, probably an old packing case, inserted a metal
plate at each end and filled it with soil. The plates were connected
to the mains, via an ammeter. Then he added water until the soil
resistance lowered, and hence the ammeter reading rose to the desired
level. It was left to simmer for hours. I can smell it now.

I have even found an old gardening book of his in which this method is
explained.

Do not try this at home! ;-)

Why? He did.

And we all survived. However, we live in different times and there are
those whose understanding of self-preservation could at best be
described as "compromised".

We have moved on from the era when you could light a coal fire with a
gas poker, connected by simply pushing a rubber tube over an outlet
pipe. A new bayonet fitting eventually replaced it.

Remember the Mammod steam engine with a neat little burner for meths. I
can still smell the distinctive aroma.

Electric heaters with very little protection for the elements.

It was once (may still be) possible to buy replacement coiled elements
for such radiant fires. You simply removed the failed one, used a piece
of string to measure the length and stretched the new one to suit.

My dad told me that in his college days (1930s) they heated a room by
simply suspending such an element from the mantelpiece.



I have done many strange things. I have woken up in the middle of the
garden in the middle of the night sitting at the garden table. I was
totally naked with cigar in one hand and cup of tea in the other.

I have woken up inside the wardrobe in a hotel dreaming that I had gone
blind. It was, of course, pitch black inside the wardrobe.

I once came to in a hotel tidying my hair in my room mirror. I then
realised that I was stark naked and the mirror was in fact a window at
the end of a corridor on a different floor from where I was sleeping.

David Hill wrote:
: On 03/09/2018 14:23, Judith in England wrote:
: A friend of mine is using an old microwave to sterilise soil before
: using for cuttings/seeds etc. in his greenhouse.
:
: Is it worth doing?
:
: Will it kill off "good things" as well as bad?
:
: Any comments?
:
: Steralising soil should do just that STERALISE it, that means killing
: off every living thing in it as well as dormant life forms.
: I have used a microwave to steralise soil to add to potting compost and
: it works well as long as you let it cook and remember to cover the top
: so the cooking is even.
: You can't cook all that much in a batch but you can do it quite quickly
: and a microwave isn't that expensive to run.
: But do it in an outbuilding and not in the kitchen, not everyone likes
: the smell of steralised soil.
: As for the reason to steralise soil. You use it in a compost miz to make
: a compost similar to the old John Innes composts - a mix of soil, sharp
: sand or crushed grit and peat.

I did once think of getting an old 45 gallon steel drum and mounting
an immersion heater in it towards the bottom. Turning the thermostat
up close to 100C, adding enough water to properly cover the element,
then adding the compost, and with the lid on (but not sealed, obviously)
lets you steam the compost!

Tom.

Ps. The email address in the header is just a spam-trap.
--
Tom Crane, Dept. Physics, Royal Holloway, University of London, Egham Hill,
Egham, Surrey, TW20 0EX, England.
Email: T dot Crane at rhul dot ac dot uk

On Mon, 3 Sep 2018 13:23:46 +0000 (UTC), Judith in England
wrote:


Will it kill off "good things" as well as bad?

A friend tried this, was so saddened to see the death of so many good
creatures, vowed never to do it again.