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seeds Surefire Rockwool Germination

Hi everyone,

I'm having a heck of a time germinating chilies in rockwool lately. I have a setup that should be more than adequate with a heat mat, humidity dome, and hygrometer (see picture below). I'm perfectly capable of reaching the 85-80F temperatures needed for pepper germination, however, I find myself constantly tinkering with the setup in terms of finding the sweet spot when it comes to humidity and moisture in the grow medium. Most of my attempts end in disaster with mold propagating within my dome and killing off my seedlings as soon as they break the seed coat. This is a likely result of overwatering and/or too much humidity.

Long story short, does anyone have a surefire method that you use when germinating in rockwool? I've seen alot of 'set it and forget it' methods on the web but I am skeptical that they will solve my moisture problem.

Any advice or suggestions appreciated!
Cheers!

For the record, I am presoaking the cubes in 5.5pH water before planting.
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Thawing the frozen north one chili at a time...
 
I've only recently starting working with Rockwool, but I've been through tons of germinations and I can share my thought process.  You're using a sterile media, so where's that amount of mold coming from in the short time most germinations take?  Have you completely sanitized the dome and trays and such? I'd start by bleaching them completely and then rinsing them very well.  Soak the rockwool then carefully shake the excess water out so the cubes aren't over-wet. Then lift the cubes to get a feel for the saturated weight and only mist lightly if they get below half that weight. Plant the seeds down into the RW a decent depth, which will get them below the very top which will dry the fastest and also help in removing the seed coat.  Leave some open venting in the dome. Keep proper temperature and most seeds should be up between one and two weeks. The cubes probably shouldn't need much more water in that amount of time. 
 
My best guess is either (1) your materials are contaminated and need a thorough cleaning, or (2) you're significantly over-watering, as once the seeds have taken on the initial water and become fully hydrated they won't need a whole lot more to germinate, assuming a typical 1-2 week hot pepper seed.  If this has only happened recently, perhaps your seed source is contaminated. In that case, change sources, but in the meantime treat the seeds for pathogens prior to sowing.
 
Hope that helps some and apologies in advance if I'm just telling you things you already know. 
 
BTW, what are you growing?  And for indoor or an early start on outdoor 2019?
 
I use Rockwool for germinating.

I don't follow the rockwool website directions.

Here's my last glog with getting seeds to germ in rockwool from last season.

2018 http://thehotpepper.com/topic/67040-mashers-2018-community-grow/?hl=masher
Post #16 has my directions for soaking and ph

After initial soaking of the cubes I only use a spray bottle to mist plugs until they get first set of true pepper leaves.

Here's another thread I shared my directions in a couple posts if interested.
Good luck and happy growing.

http://thehotpepper.com/topic/63475-rockwool-in-soil-can-it-be-done/?hl=rockwool
 
I've never had mold in 12 yrs using rockwool.

I do get green algae on plug surfaces of long germination seeds from time to time.

I'll be using cubes again this season starting in Feb.
 
Masher said:
I use Rockwool for germinating.

...

After initial soaking of the cubes I only use a spray bottle to mist plugs until they get first set of true pepper leaves.
 
 

Masher, that's a great looking germination setup you have - and a killer greenhouse!  Do you remember how regularly you had to mist those (1 inch?) rockwool cubes after initial germination?  I've used bigger cubes which would tend to hold moisture a good while, but then again you have a fair amount of RW mass under that humidome,  I wouldn't think yours would require much additional water, at least until the first couple weeks were over and you're chasing the stubborn stragglers.
 
CaneDog said:
I've only recently starting working with Rockwool, but I've been through tons of germinations and I can share my thought process.  You're using a sterile media, so where's that amount of mold coming from in the short time most germinations take?  Have you completely sanitized the dome and trays and such? I'd start by bleaching them completely and then rinsing them very well.  Soak the rockwool then carefully shake the excess water out so the cubes aren't over-wet. Then lift the cubes to get a feel for the saturated weight and only mist lightly if they get below half that weight. Plant the seeds down into the RW a decent depth, which will get them below the very top which will dry the fastest and also help in removing the seed coat.  Leave some open venting in the dome. Keep proper temperature and most seeds should be up between one and two weeks. The cubes probably shouldn't need much more water in that amount of time. 
 
My best guess is either (1) your materials are contaminated and need a thorough cleaning, or (2) you're significantly over-watering, as once the seeds have taken on the initial water and become fully hydrated they won't need a whole lot more to germinate, assuming a typical 1-2 week hot pepper seed.  If this has only happened recently, perhaps your seed source is contaminated. In that case, change sources, but in the meantime treat the seeds for pathogens prior to sowing.
 
Hope that helps some and apologies in advance if I'm just telling you things you already know. 
 
BTW, what are you growing?  And for indoor or an early start on outdoor 2019?
I clean everything in a soap/bleach solution before I plant anything so I suspect the seeds might be bringing in the fungus. Maybe a treatment of peroxide before planting might solve the problem.

Overwatering is my main issue, and maybe I need more practice with rockwool. Misting the top when they dry is a good idea, thanks!

I'm volunteering for a school and I'm showcasing some hydroponic chilies grown in a folgers coffee container. I will start my seeds for outside growing in Feb/March. Chocolate ghosts and Jamaican chocolates right now.

Thawing the frozen north one chili at a time...
 
Would you keep all vents in the dome closed after soaking or keep them open for better air flow (I tend to side with this option)?

Thawing the frozen north one chili at a time...
 
That's awesome that you're sharing about growing peppers!  Cool varieties too.  I'd go with vents open. Aren't too many situations I'd close them. 
 
I think yeah, just aim for lightly moist-versus-wet and maybe pre-treatment like NE_ChileMan suggests - certainly there's other treatment methods too - and I would expect things to be pretty straightforward with good results.
 
Hope you can post a few pictures as your Folgers grow develops!
 
 
I keep vents open as long as it collects moisture inside the dome.

1/4 vent, 1/2 vent, full vent. No vent. Whatever is needed to keep humidity inside the dome.


After the initial soaking...I don't water them again until the cubes have exposed roots.

I mist plants and cubes as needed to maintain the humidity so it's pretty easy using that as a visual, but monitor closely, it's easy to apply a couple TBLS if needed to keep plug moist and protect from drying out the cube.

Once the stem up about 2 inches I reduce moisture and humidity to begin a hardening off so they don't get stem rot.
 
CaneDog said:
That's awesome that you're sharing about growing peppers!  Cool varieties too.  I'd go with vents open. Aren't too many situations I'd close them. 
 
I think yeah, just aim for lightly moist-versus-wet and maybe pre-treatment like NE_ChileMan suggests - certainly there's other treatment methods too - and I would expect things to be pretty straightforward with good results.
 
Hope you can post a few pictures as your Folgers grow develops!
 
Much appreciated, guys. I might do a growing log (glog?) sometime in the near future if I can mediate this issue. Should be sorted after I use all of that great advice!

Thawing the frozen north one chili at a time...
 
I dont use rockwool often for Peppers. I have coco pellets that work great then transfer two inch seeding to rockwool if needed.

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