Mold on seed starting trays? Tips on germinating eggplants?

[Svea]

Hello, I started some tomatoes and eggplants about 2 weeks ago and within days there was a thin layer of white mold on the substrate. It's 75/25 organic seed starting mix to organic worm castings. I set it out in the sun for the day and it burned it off but it's come back. The tomato seedlings are thriving and don't seem to care about it. My eggplants haven't sprouted yet. I have them under a grow light and I had accidentally overwatered them until a few days ago. I used the same soil and grow lights last year.
1. Is this something I should worry about or is it no big deal? What could be causing this?
2. Any tips on getting eggplants to sprout? I'm starting to get a little worried my seeds aren't good anymore...

Thanks!

 

[DirtMechanic]

The thing about seeds is everything they need is onboard. That is one reason why seed starting mix is just a medium. Are you using heat mats? Is it cold in that room? I doubt it is 80f. Some plants are heatseekers and some are not. Search for seeding temps on the site. I want to say @Chuck posted a plant temp list once upon a time.

 

[Chuck]

https://sacmg.ucanr.edu/files/164220.pdf

I would replant with fresh seeds. The white mold is "probably" harmless and is caused by the soil staying too wet.

 

[Svea]

The thing about seeds is everything they need is onboard. That is one reason why seed starting mix is just a medium. Are you using heat mats? Is it cold in that room? I doubt it is 80f. Some plants are heatseekers and some are not. Search for seeding temps on the site. I want to say @Chuck posted a plant temp list once upon a time.

It's 72F in the room. I haven't used a heat mat before but I think I have one somewhere.

 

[Svea]

https://sacmg.ucanr.edu/files/164220.pdf

I would replant with fresh seeds. The white mold is "probably" harmless and is caused by the soil staying too wet.

Will do. Is putting them in a moist paper towel until they germinate and then potting them inadvisable for any reason? I want to make sure my seeds are still good at the same time because they're a year or two old.

 

[Chuck]

Will do. Is putting them in a moist paper towel until they germinate and then potting them inadvisable for any reason? I want to make sure my seeds are still good at the same time because they're a year or two old.

It will be perfectly fine if you have proper lighting.

 

[DirtMechanic]

It's 72F in the room. I haven't used a heat mat before but I think I have one somewhere.

I use a bit of cardboard to mellow my mats to 80f. One could buy a controller too I guess.

 

[lifegardener]

Hello, I started some tomatoes and eggplants about 2 weeks ago and within days there was a thin layer of white mold on the substrate. It's 75/25 organic seed starting mix to organic worm castings. I set it out in the sun for the day and it burned it off but it's come back. The tomato seedlings are thriving and don't seem to care about it. My eggplants haven't sprouted yet. I have them under a grow light and I had accidentally overwatered them until a few days ago. I used the same soil and grow lights last year.
1. Is this something I should worry about or is it no big deal? What could be causing this?
2. Any tips on getting eggplants to sprout? I'm starting to get a little worried my seeds aren't good anymore...

Thanks!

Too much water/moisture often causes that condition.

 

[Oliver Buckle]

Will do. Is putting them in a moist paper towel until they germinate and then potting them inadvisable for any reason? I want to make sure my seeds are still good at the same time because they're a year or two old.

Keep a close eye and pot as soon as they show signs of germinating, the tiny new roots embed into the tissue sometimes and get damaged when you lift them out. Some seeds need light, but not most, I used to do well with a couple of layers of tissue in the bottom of a margarine tub buried in the towels in the days when we had an airing cupboard. the lid ensures it stays nice and humid.

 

[oneeye]

Hello, I started some tomatoes and eggplants about 2 weeks ago and within days there was a thin layer of white mold on the substrate. It's 75/25 organic seed starting mix to organic worm castings. I set it out in the sun for the day and it burned it off but it's come back. The tomato seedlings are thriving and don't seem to care about it. My eggplants haven't sprouted yet. I have them under a grow light and I had accidentally overwatered them until a few days ago. I used the same soil and grow lights last year.
1. Is this something I should worry about or is it no big deal? What could be causing this?
2. Any tips on getting eggplants to sprout? I'm starting to get a little worried my seeds aren't good anymore...

Thanks!

Yes if you weigh the small cups that you germinate the seeds in you can better manage the water intake. Its easy to drown that tiny seed or displace them from watering. I use dixie cups and write the dry weight and wet on top of the cup. When the cup water holding capacity gets to 20 grams its time to water adding another 100 grams of water. I only use this method on hard-to-germ seeds.