Author Topic: Advice needed regarding moldy seed starting mix  (Read 1741 times)

emegar

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Advice needed regarding moldy seed starting mix
« on: December 29, 2013, 02:03:07 PM »
I received an order of seeds from Helton recently that I soaked in Physan and put in cups with coconut coir, peat moss, and vermiculite. Now I'm seeing mold on the surface of the mix. They're in my greenhouse, staying fairly damp in the still air. I'd really rather not dump the mix and start over, but I also don't want to lose the seeds. This page (http://www.firstrays.com/physan.htm) suggests soaking seeds or seedlings in Physan can prevent damping off, but I hesitate to drench my seed cups in the stuff. Any advice?
James

Sven

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Re: Advice needed regarding moldy seed starting mix
« Reply #1 on: December 29, 2013, 08:59:05 PM »
Hi Emegar,

This article has a lot of good tips:  http://davesgarden.com/guides/articles/view/277/

It's good to let them dry out some between waterings.  Was the potting mix sterile?  Some molds won't hurt anything, but others will. 

"We follow the school of thought that seedlings and plants should be watered deeply when they begin to dry out, and then left until they begin to dry out again... If you are seeing mold, it is a sure sign of too much moisture for too long; mold will grow when there is a constant source of moisture"

Read more: http://davesgarden.com/community/forums/t/833558/#ixzz2ouztesOd

Good luck, I'm hoping they come up.

Sven

PltdWorld

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Re: Advice needed regarding moldy seed starting mix
« Reply #2 on: December 29, 2013, 09:11:34 PM »
I see mold when I use perlite more often than not.  It may be that it's always somewhat present and just shows up more on  the white background, or may be that mold grows better on perlite.  Not sure.  Either way, I've noticed that the soil in my greenhouse plants is much slower to dry out with the colder weather.

emegar

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Re: Advice needed regarding moldy seed starting mix
« Reply #3 on: December 30, 2013, 12:04:12 AM »
Thanks guys. I think I probably need to install a fan at some point. For now I've elected to try watering once with an antifungal added to the water and then letting the mix dry out a bit before the next watering. I'm hoping there won't be a recurrence in the meantime.
James

Mark in Texas

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Re: Advice needed regarding moldy seed starting mix
« Reply #4 on: December 31, 2013, 10:39:36 AM »
1.  Hydrate your seed until the seedcoat cracks.  If it sinks, it has an embryo.  If it floats, it has an air pocket.  I've used Consan for 30 years.  It's OK.  I would soak my seeds in a mix of 1 TBSP. of household bleach to one gallon of water for 15 minutes to insure no fungus/mold spores.  Drain off the mix and then add clean water.  No need to rinse.  Just dump your seeds in a jigger or small glass and add clean water until it hydrates.

2.  Heat your seedling mix to 170F (no higher) and hold it there for 30 minutes stirring a couple of times to insure it's heated thru and thru.

When your seed has cracked and you see the tip of the radicle sow it pointed end up, radicle down, 2 1/2 times deep as the diameter of the seed.

Good luck
« Last Edit: December 31, 2013, 04:20:03 PM by Mark in Texas »

Mark in Texas

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Re: Advice needed regarding moldy seed starting mix
« Reply #5 on: December 31, 2013, 10:42:07 AM »
Hi Emegar,

This article has a lot of good tips:  http://davesgarden.com/guides/articles/view/277/

Bad info on heating to 200F.  That will induce carbonization of the humus, reason why it stinks and can be injurious regarding seed viability.  Author even admitted it smelled. 180F max, which will insure any pythium spores have been killed. 
« Last Edit: December 31, 2013, 10:46:23 AM by Mark in Texas »

emegar

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Re: Advice needed regarding moldy seed starting mix
« Reply #6 on: December 31, 2013, 10:53:51 AM »
Thanks for all the great advice, Mark. You've clearly done a lot of research on best practices for seed germination. I've been lazy when it comes to sterilizing my mix and have usually gotten away with it. May be time for me to make a change in my procedures.
James

EvilFruit

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Re: Advice needed regarding moldy seed starting mix
« Reply #7 on: December 31, 2013, 10:59:53 AM »
I always Soak my seeds for 10 min in a fungicide solution (Copper oxychloride) before planting . I highly recommend Adding more perlite to your soil mix to give more breathing area for the seeds.

Mohd
Moh'd

 

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