Starting flowers from seed

[Buckeye303]

Hello all, I've always had a green thumb but just started growing flowers from seed indoors. I planted 12 different seeds in a 72 seed bulk tray, 6 in each column. I'm three days in and already have 4 of the 12 flowers sprouting! But here's where my inexperience slows me down.

I know new sprouts need lots of light, and I have a good grow light that I've been using 15-16 hours a day to help growth. But I also know that seeds that haven't germinated don't need light, and sometimes prefer darkness.

So my question to you all is since some seeds have germinated (and aren't mature enough to transplant) and some haven't, will 16 hours of light hurt the unsprouted seeds? Should I take the lid off that I use to keep moisture in? I've also backed the light off to about 6 inches above the plants, as opposed to the two inches it recommends in fear that it'll stunt the seeds that haven't sprouted from sprouting.

Sorry for the long post, any advice helps!

 

[marlingardener]

Buckeye, we start seeds inside, mostly vegetables and a few herbs, and they have different sprouting times. We have a four-shelf set up, so the seeds that have sprouted and are showing their primary leaves can go to a lower shelf without a heat mat and cover.
Your seeds that are getting 16 hours of light won't be hurt (they are under soil and don't get the benefit of light) but when they sprout the light will be beneficial. The plastic cover/dome to keep moisture in is very good for the seed beds. We usually leave the dome on for two or three days after the seeds sprout, then remove it and take the tray off the heat pads.
If you've backed off the light to six inches above the plants you'll run the risk of getting lanky plants that are reaching for the light. Take the light down to the recommended two inches. Light won't keep the unsprouted seeds from coming up.
The first year we tried starting seeds indoors, we had a big damping off problem. We found that putting a teaspoon of baking soda in a pint of water and misting both the plants and the soil took care of it.
Don't worry about the long post--you were very clear about your concerns and in asking for specific advice. Good luck with your flowers, and we'll be looking forward to seeing photos of your flower garden!

 

[marlingardener]

I realized that my description of the seed growing shelves wasn't very good--so here is a photo of our set-up. You can see that the top shelf has the
clear plastic cover over the seed containers and there is a heat mat under it: the second shelf has sprouted seedlings about 2" from the lights (the tray is supported by a carrying tray, and as the seedlings grow, the carrying tray is removed); and the third shelf has younger and smaller seedlings near the lights and as they grow, the supporting tray will be removed. Second and third shelves don't have heat mats.
(Carrying trays are the fairly sturdy perforated trays that nurseries have for customers to carry plants in.)

 

[Buckeye303]

Marlin thank you so much. This answered about every question I had that seemed to be impossible to find online.

The irony in all of this is that I'm doing almost the opposite of what everyone else does this time of year. I'm trying to grow northern flowers at my home here in southwest Florida. And I'm doing it at the wrong time of year (late summer would be ideal) but it's exciting to say the least. My home is almost always around 75 degrees and I don't think I have the need for a heat mat. I actually would like to keep the soil a little cooler than what it is but haven't found a good method. I may be nitpicking about a few degrees here, even though I'm fairly certain my larkspur won't sprout in the warm soil. And there's a good chance half of these won't last very long outdoors here once April comes around. But hey, it's worth a try anyways!

Thank you again for the advice and the picture of your setup. That's what I'll be aiming for. Just need a deer fence to keep my toddlers out!

Happy gardening

 

[Becky]

Sounds like an interesting project @Buckeye303, you'll have to keep us all posted how it goes

 

[Buckeye303]

Thank you I will!

One more question. Is this a white fungus due to overly humid conditions? The "white fuzz" is covering the seed and nothing else

 

[Beth_B]

Hi Buckeye.

I believe that's caused by keeping your soil just a little too moist; you're correct. You can use your finger or a piece of paper to wipe the fungus away, it won't hurt your seedlings but overly damp conditions will. If you back off on the water a bit it should resolve itself.

Also how are you watering? When I've started seeds (and I am no expert btw) I've kept them in shallow trays in peat pots, and added water to the trays so it's absorbed up through the soil. I'm thinking keeping the surface moist may promote fungus. You want sufficient (but not too much) water getting to the baby roots, not what is above the soil line.

 

[marlingardener]

You can take care of the fungus by spraying the soil with a tablespoon of baking soda in a pint of tepid water. A bottle with a fine mist setting works great.
As Beth said, you probably have too moist potting mix. When we start seeds, we spray the pots from the top to settle the seeds in, then afterwards, only water from the bottom.
Don't worry--you haven't damaged anything--but do back off a bit on the moisture.

 

[Buckeye303]

Thank you both. I water occasionally with a spray bottle, so far about once every two to three days or whenever it looks like the soil is drying out. I never soak them, usually about 4 or 5 squirts. The tray is designed to water from the bottom so I'll be doing that from now on. How far up do you fill it? So it reaches the very bottom of the cells? Or further up?

Thanks for the solutions to the fungus as well. And thanks again for answering my endless multitude of questions lol. It's very much appreciated.

 

[Beth_B]

Well with peat pots, last year I successfully germinated a bunch of heirloom tomato seeds. I think at the very most, maybe about an eighth or kquarter inch of water into the tray, then let it dry completely before adding more.

That's tomatoes mind you...A fruit that tends to do well in warm, drier Mediterranean type climates. Apart from some tropical plants, most of the world has extended periods of little rain, so keeping most plants constantly moist is not replicating a natural environment.

I'm guessing from your name you are from Ohio originally? If your flowers are native to the Midwest, think about how much rain they'd be getting in spring. Highly variable... Occasionally soaked but with extended periods of no rain at all.

 

[Buckeye303]

Yes you are correct! Ohio born, Florida raised. But I still love my Ohio flowers.