Repeated misting in a greenhouse environment - Orchid Board

ArronOB · #1 03-08-2020, 06:22 AM

Hi. I was browsing a publication of the NZ Miltonopsis Society, which this link may or may not point too
http://www.odontalliance.org/affilia...%20no.%203.pdf

What interested me was an article on page 12 by a grower on the NSW Central Coast (where I live) with a wide variety of orchids growing in unheated shadehouses who says he has a very fine misting setup that comes on for 30 seconds every half hour between 6am and 6pm, so 24 times per day.

Bear in mind that this is in environment already on the humid side of average.

This is he first time I’ve heard of such frequent ‘misting’ for shadehouse growing.

Has anyone else tried this, and what was the result.

Incidentally, further down he says he uses an ebb and flow system for his paphs. Again, first time I’ve heard of that with orchids. My experience of ebb and flow was in hydroponic systems - full hydroponics not semi. Can anyone speculate on exactly how he uses the ebb and flow ?

Ray · #2 03-08-2020, 12:49 PM

There’s misting, and then there’s misting...

My only real concern would be if the plants stayed wet.

Semi-hydroponics IS ebb and flow, but operated manually and less frequently, don’t you think? The biggest difference, in my opinion, is that the water in S/H is “one and done”, rather than being shared (potentially with pathogens) in a common, repeatedly-applied reservoir.

early · #3 03-08-2020, 01:54 PM

Quote:

Originally Posted by Ray

There’s misting, and then there’s misting...

My only real concern would be if the plants stayed wet.

Semi-hydroponics IS ebb and flow, but operated manually and less frequently, don’t you think? The biggest difference, in my opinion, is that the water in S/H is “one and done”, rather than being shared (potentially with pathogens) in a common, repeatedly-applied reservoir.

Thanks Ray. I was being lazy re-poured the drained water from the S/H plants back over that orchid or the neighboring ones.
This AM I check that drained water for pH and it was greater than 7. In the future I will toss all of that and keep my well water 5.5 to 6.5 nearby and with weak
20-20-20 and I have switched from trying to lower my over 8 well water with vinegar instead of citric acid power since it is easier for me to measure.

SouthPark · #4 03-08-2020, 03:53 PM

Misting should be ok, as long as there's adequate air-movement in the area to avoid issues with certain kinds of organisms growing - related to fungal or bacterial issues.

DirtyCoconuts · #5 04-06-2020, 08:42 PM

Yeah ray nailed It. Common Rez vs individual Rez

I had a buddy who owned a hydro shop a while back (man! Do I wish he still did, so much orchid crossover stuff!!!!)
And he would say that the growers would combat that by including systemic antibacterial and anti fungal stuff in with the nutes so they could minimize the mass illness/fungus destroying a whole crop

I don’t share water based on the fervent advice of the growers on this board. Having been very blessed to have gone my decades of habit botany without really issues like fungus and viruses. Soooo I’m learning from the experience of others and just taking the extra step

I am not militant. I let stuff drip onto plants below them and such but I don’t “share” water

Brian1212 · #6 04-07-2020, 07:35 PM

Aerial roots can absorb moisture from the air if the air has enough of it. Misting that often would certainly ensure that but the roots would never be saturated with too much moisture either like you can get with watering in pots.

As to the Ebb and flow. You are too focused on the wording but basically all ebb and flow is is watering from below once a day for 10 minutes or so.. Forget it being hydroponics or not, that is what happens. All hydroponics is is growing without the use of soil. Lava rock, clay pebbles, perlite, coco coir and bark are soil-less. As such I would argue that most orchids are grown in hydroponic media by default and there is no difference growing orchids in clay pebbles watered by hand to plants grown in hydroponic setups watered by timers.

You can easily replicate Ebb and flow by dunking your plants manually into a bucket of water and let them soak for 10 minutes every day.

Whether you call it watering your plants or Ebb and flow, the plants are getting watered the same way, one by timer and pump, the other by lifting and dunking by hand.

So yes Ebb and flow is nothing new or special, pretty much every orchid grower does it to some extent without realizing they are doing ebb and flow by hand.

Semi-hydroponics on the other hand is an invented term, which is just placing the plant into some clay pebbles into a layer of water at the bottom permanently. Whether you call it placing the plant in a bowl of water or semi-hydroponics is the same - most people prefer the fancier sounding semi-hydroponics.

Roberta · #7 04-07-2020, 07:47 PM

An important factor in the semi-hydroponic method of growing is the flushing of the environment - the container is filled to the top, and then drains leaving a small amount of water in the reservoir to provide humidity and wick up into the root zone. The flushing process brings air into the root zone and avoids a buildup of salts.

Bayard · #8 04-09-2020, 03:58 PM

I keep my cool growers in the “mist zone” under the fogger in my greenhouse. Come summertime, they are wet from mist most of the day. However, the fogger is plumbed with RO water, so no issues with mineral buildup.

SouthPark · #9 04-09-2020, 07:14 PM

Quote:

Originally Posted by Brian1212

All hydroponics is is growing without the use of soil. Lava rock, clay pebbles, perlite, coco coir and bark are soil-less. As such I would argue that most orchids are grown in hydroponic media by default and there is no difference growing orchids in clay pebbles watered by hand to plants grown in hydroponic setups watered by timers.

Hi there Brian. I thought that hydroponic media is pretty much just water (plus some nutrients). The water is the media. Roots fully submerged all of the time. Media like rocks etc are just extra optional extras.

Quote:

Originally Posted by Brian1212

So yes Ebb and flow is nothing new or special, pretty much every orchid grower does it to some extent without realizing they are doing ebb and flow by hand.

'Ebb and flow ' needs to be defined properly off course. If it's defined as a mass of water rising from below (flowing in from below, or from the side), and then later reversing the direction ------ then that would be flow and ebb (or ebb and flow). But 'watering by hand' is coming from overhead in general, may be same overall aim or goal achieved (as in wetting the media and roots).

But - on the other hand - if I purposely focus more water in some regions of the media than other regions, or if I purposely do very light watering from overhead over all of the media, then that will be quite different in terms of water coming up from the bottom and saturating everything.