Mist propagation was mentioned in another thread quite recently. That
triggered me into asking something I have always wanted to know:

What does mist propagation do which cannot be done by inverting a
transparent container over the cutting?
I have always thought that the purpose of either action is simply to
maintain an atmosphere which is as nearly as possible fully saturated with
water vapour in order to minimise evaporation from the surfaces of the
leaves.

Franz

Franz Heymann wrote:
Mist propagation was mentioned in another thread quite recently. That
triggered me into asking something I have always wanted to know:

What does mist propagation do which cannot be done by inverting a
transparent container over the cutting?
I have always thought that the purpose of either action is simply to
maintain an atmosphere which is as nearly as possible fully saturated with
water vapour in order to minimise evaporation from the surfaces of the
leaves.

Franz


Not much ;~)) It does keep the top of the cutting cool which helps in
the summer. The maxim was 'cool tops/warm bottoms'. A big problem with
the plastic bag or closed propagator approach is the high temperstures
you get with even a small amount of sunshine - the cuttings get cooked
quite easily. That said, if used with care it works well for a great
many plants. The aim in each case is to keep the cutting turgid for as
long as it takes to get rooted. The big advantage of mist or the more
modern fogging systems is huge throughput from quite a small unit but
that's usually irrelevant in a private garden situation. Many nurseries
opt for slower, less intensive methods needing less capital outlay -
reserving mist propagation etc for more difficult subjects. There are
also a few plants that don't respond well to those conditions.

Rod

"Rod" wrote in message
...
Franz Heymann wrote:
Mist propagation was mentioned in another thread quite recently. That
triggered me into asking something I have always wanted to know:

What does mist propagation do which cannot be done by inverting a
transparent container over the cutting?
I have always thought that the purpose of either action is simply to
maintain an atmosphere which is as nearly as possible fully saturated
with
water vapour in order to minimise evaporation from the surfaces of the
leaves.

Franz


Not much ;~)) It does keep the top of the cutting cool which helps in
the summer.

How does the mist keep it cool? Since the local air is saturated, there
cannot be much by way of cooling evaporation (after all, this is what the
mist is supposed to stop).

The maxim was 'cool tops/warm bottoms'. A big problem with
the plastic bag or closed propagator approach is the high temperstures
you get with even a small amount of sunshine - the cuttings get cooked
quite easily.

But one does not keep the covered cuttings in straight sunshine. Mine are
always kept agains a North facing wall or suchlike until they have rooted.

[snip]

Franz

Franz Heymann wrote:

Mist propagation was mentioned in another thread quite recently. That
triggered me into asking something I have always wanted to know:

What does mist propagation do which cannot be done by inverting a
transparent container over the cutting?
I have always thought that the purpose of either action is simply to
maintain an atmosphere which is as nearly as possible fully saturated with
water vapour in order to minimise evaporation from the surfaces of the
leaves.


It's automated, air circulation is better , thus you have a more bouyant
atmostphere (which in turn 'should' reduce fungal risk to some degree).

A mist bench may be covered or uncovered. heated or unheated, though
ususally the former..

Its worth noting that misting, in Horticultural terms, is not quite the
same as fogging.

True fogging equipment, such as is used to fog large glass-houses is
quite expensive and very different from a low scale sand and mist bench
rooting bench, which can be anything from a DIY 'heath robinson' affair
to some very high tech systems.

//
Jim

"........Its worth noting that misting, in Horticultural terms, is not quite
the same as fogging.........."

But with a closed atmosphere then Fogging may be an interesting idea as it
puts out a lot less water.
Something I am going to experiment with in the coming season.


--
David Hill
Abacus nurseries
www.abacus-nurseries.co.uk

David Hill wrote:

"........Its worth noting that misting, in Horticultural terms, is not quite
the same as fogging.........."

But with a closed atmosphere then Fogging may be an interesting idea as it
puts out a lot less water.
Something I am going to experiment with in the coming season.

Wish I could afford 'experiments' like that;-)
//
Jim

"Jim W" wrote in message
news:1g3g6gz.vesamxyagc56N%00senetnospamtodayta@ma cunlimited.net...
Franz Heymann wrote:

Mist propagation was mentioned in another thread quite recently. That
triggered me into asking something I have always wanted to know:

What does mist propagation do which cannot be done by inverting a
transparent container over the cutting?
I have always thought that the purpose of either action is simply to
maintain an atmosphere which is as nearly as possible fully saturated
with
water vapour in order to minimise evaporation from the surfaces of the
leaves.


It's automated, air circulation is better , thus you have a more bouyant
atmostphere (which in turn 'should' reduce fungal risk to some degree).

What does "bouyant atmosphere" mean?
Why should it reduce the risk of fungi? If the fungus spores are there,
they will be there, whether the atmosphere is bouyant or not, whatever
bouyant might mean.

Franz

The message
from "Franz Heymann" contains these words:

Not much ;~)) It does keep the top of the cutting cool which helps in
the summer.

How does the mist keep it cool? Since the local air is saturated, there
cannot be much by way of cooling evaporation (after all, this is what the
mist is supposed to stop).

It doesn't: it just prevents the cutting drying out.

The maxim was 'cool tops/warm bottoms'. A big problem with
the plastic bag or closed propagator approach is the high temperstures
you get with even a small amount of sunshine - the cuttings get cooked
quite easily.

But one does not keep the covered cuttings in straight sunshine. Mine are
always kept agains a North facing wall or suchlike until they have rooted.

That's my approach. Either that or as I don't have a north-facing wall,
shade them.

--
Rusty Hinge
horrid·squeak&zetnet·co·uk
http://www.users.zetnet.co.uk/hi-fi/tqt.htm

".........Wish I could afford 'experiments' like that;......."

Well my fogger cost £9.95 from Maplin (special offer)
uses around 3/4 pint of water an hour on continuous running, but with a
timer I am going to try 15 mins on 15 mins off, You get more fog from warm
water so if it is in contact with the soil warming cable should work better.
Will probably require a very low volume fan but should find something low
cost, only need around 3inch.
The larger fogging machines such as they use in disco's seem not to run on
water.....pity as for under £40 you can get a machine with quite an output
(Maplin do one for £44.00 that has an output of 2,500 cubic feet per
minute).
With that you could do a whole glasshouse minute.
did see 2 at a trade show One £800+ and the other around £1400.
The control unit for Mist is getting on for £200 so this could be a much
more cost effective system and not put out so much water, so that things
like Dahlias that don't like being wet could benefit.

--
David Hill
Abacus nurseries
www.abacus-nurseries.co.uk

"Franz Heymann" wrote in message
...

"Jim W" wrote in message
news:1g3g6gz.vesamxyagc56N%00senetnospamtodayta@ma cunlimited.net...
Franz Heymann wrote:

Mist propagation was mentioned in another thread quite recently. That
triggered me into asking something I have always wanted to know:

What does mist propagation do which cannot be done by inverting a
transparent container over the cutting?
I have always thought that the purpose of either action is simply to
maintain an atmosphere which is as nearly as possible fully saturated
with
water vapour in order to minimise evaporation from the surfaces of the
leaves.


It's automated, air circulation is better , thus you have a more bouyant
atmostphere (which in turn 'should' reduce fungal risk to some degree).

What does "bouyant atmosphere" mean?
Why should it reduce the risk of fungi? If the fungus spores are there,
they will be there, whether the atmosphere is bouyant or not, whatever
bouyant might mean.

Franz


I've read that by slightly over-misting, the water runoff from the leaves
removes fungal spores.
Over-misting is achieved either by a timer which runs after the "electronic
leaf" has indicated saturation or by moving the sensor to the extreme of the
mist distance so that it is saturated last. The timer method is preferred as
being more consistent.

Since the aim is to have near-continuous 100% humidity a "buoyant
atmosphere" seems unlikely. The action of the misting nozzles will, however,
stir up the air a bit.
The water to the mister nozzle(s) will normally be considerably cooler than
the air temperature and so will cool the plants whilst the mister is
actually operating. Covered/closed systems controlled only by an electronic
leaf may experience severe temperature cycling.

None of the above is from my own practical experience. I was considering
making a mister but got drawn into rebuilding the kitchen since when the
garden has gone to rack and ruin. Got a bumper crop of Cape Gooseberries
though - they seemed to thrive on lack of attention!.

HTH

Mike

"Jaques d'Altrades" wrote in message
...
The message
from "Franz Heymann" contains these
words:

Not much ;~)) It does keep the top of the cutting cool which helps in
the summer.

How does the mist keep it cool? Since the local air is saturated, there
cannot be much by way of cooling evaporation (after all, this is what
the
mist is supposed to stop).

It doesn't: it just prevents the cutting drying out.

The maxim was 'cool tops/warm bottoms'. A big problem with
the plastic bag or closed propagator approach is the high temperstures
you get with even a small amount of sunshine - the cuttings get cooked
quite easily.

But one does not keep the covered cuttings in straight sunshine. Mine
are
always kept agains a North facing wall or suchlike until they have
rooted.

That's my approach. Either that or as I don't have a north-facing wall,
shade them.

Yes.

Franz

"Mike Hunter" wrote in message
...

[snip]

I've read that by slightly over-misting, the water runoff from the leaves
removes fungal spores.

This sounds like wishful thinking.
Surely, if there are spores around in the air, the mist is as likely to trap
spores in the air and deposit them on the leaf.


Over-misting is achieved either by a timer which runs after the
"electronic
leaf" has indicated saturation or by moving the sensor to the extreme of
the
mist distance so that it is saturated last. The timer method is preferred
as
being more consistent.

Since the aim is to have near-continuous 100% humidity a "buoyant
atmosphere" seems unlikely. The action of the misting nozzles will,
however,
stir up the air a bit.

I still don't have a clue as to what might be meant by a "bouyant
atmosphere"

The water to the mister nozzle(s) will normally be considerably cooler
than
the air temperature and so will cool the plants whilst the mister is
actually operating. Covered/closed systems controlled only by an
electronic
leaf may experience severe temperature cycling.

None of the above is from my own practical experience. I was considering
making a mister but got drawn into rebuilding the kitchen since when the
garden has gone to rack and ruin. Got a bumper crop of Cape Gooseberries
though - they seemed to thrive on lack of attention!.

I suspect that you have decided on the more productive dourse of action.
That is, unless you are a professional nurseryman who has to produce
thousands of cuttings of a kind.

Franz

"Franz Heymann" wrote in message
...
Mist propagation was mentioned in another thread quite recently. That
triggered me into asking something I have always wanted to know:

What does mist propagation do which cannot be done by inverting a
transparent container over the cutting?
I have always thought that the purpose of either action is simply to
maintain an atmosphere which is as nearly as possible fully saturated with
water vapour in order to minimise evaporation from the surfaces of the
leaves.

Franz

The best way of rooting things is indeed 100% humidity but cuttings also
respond to cool tops and warm bottoms, with a sealed container it is very
difficult to achieve, although some gardeners I know achieve good results
with a dew point cabinet, however the main advantage of mist is the almost
complete absence of fungal problems such as botrytus
--
Charlie, gardening in Cornwall.
http://www.roselandhouse.co.uk
Holders of National Plant Collection of Clematis viticella (cvs)

On Sun, 26 Oct 2003 22:43:47 +0000 (UTC), "Franz Heymann"
wrote:


"Jim W" wrote in message
news:1g3g6gz.vesamxyagc56N%00senetnospamtodayta@m acunlimited.net...
Franz Heymann wrote:

Mist propagation was mentioned in another thread quite recently. That
triggered me into asking something I have always wanted to know:

What does mist propagation do which cannot be done by inverting a
transparent container over the cutting?
I have always thought that the purpose of either action is simply to
maintain an atmosphere which is as nearly as possible fully saturated
with
water vapour in order to minimise evaporation from the surfaces of the
leaves.


It's automated, air circulation is better , thus you have a more bouyant
atmostphere (which in turn 'should' reduce fungal risk to some degree).

What does "bouyant atmosphere" mean?
Why should it reduce the risk of fungi? If the fungus spores are there,
they will be there, whether the atmosphere is bouyant or not, whatever
bouyant might mean.

buoyant?
--
Martin

"Charlie Pridham" wrote in message
...

[snip]

The best way of rooting things is indeed 100% humidity but cuttings also
respond to cool tops and warm bottoms, with a sealed container it is very
difficult to achieve, although some gardeners I know achieve good results
with a dew point cabinet, however the main advantage of mist is the almost
complete absence of fungal problems such as botrytus

I find this idea very interesting, if I understand it correctly. Is the
idea to keep the air above the cutting at the dew point by having a wet
cloth wrapped round the cover, so that the ecvaporation from the cloth
lowers the air inside the box to somewhere near the dewpoint?

Franz