You are giving them too much water. I tried for a few years before I got it right. In big greenhouses they are never watered. They are run on a coveyer belt under misters.This is how I do mine.

I use a heating mat underneath--I use a humidity cover, a good seed starting soiless mix and a spray bottle.
I wet the soil thouroughly before I fill the containers. You want it wet but not sopping. I squeeze a handful and a little water should come out. If its too wet add more soil and mix. Then I fill my containers and sprinkle my seeds on top. They need light to germinate so don't cover them.

I put them on the heating mat with the humidity cover on. Excessive heat will cause them not to germinate so make sure you just have enough heat to warm the soil a bit. After that I wait 2 days and then about 4 times a day I spritz them with the the spray bottle. I keep doing this until they are ready to be transplanted. You will have to water at some time. Make sure you don't do it excessivly and never let what's ounder them have standing water

They need light to germinate so don't cover them.

that is the one secret i didn't do.

the seed packet says to cover.

will give another try

I have a question...why would you need to mist them, if they are under the humidity dome? Wouldn't that be enough moisture?

not under humidity dome. Biggest cause of dampening off which i constantly fight.

Two days ago spent all day at an annual grower that supplies all of west MI Home Depot. green houses as big as foot ball fields. Asked all kinds of questions. There starting mix is 80% peat, 12% vermiculite, 8% pearlite. Fanatical on hygene and eliminating pathogins. Even had to step on Chlorex soaked pads before entering green houses. Both for controlling disease to seedlings and for eleminating any disease as they ship across state lines.
They do not cover seeds, was told almost all seeds germinate uncovered as they do in nature, My guide said no problem getting impatients going. Start New Guiney from cuttings, just stick into same potting mix and NO hormone powder---too harsh. The whole secret is humidity, heat and light They heat from bottom to 72. Air circulation important in eliminating dampening off, also keeping surface dry and using a sterile mix,

They don't even use trays over again. Send to plastic recycler to grind up and remold. more efficient than a Chlorine wash.

they Add 2% chlorine to water as they have well water. City water is 3.5% also use both a basic and acidic liquid fert added to misters and drip system. . I'm starting to add 2% chlorine as i have well water and have sterilized all starting medium in the microwave 3 min until it reaches 200.

I am experimenting with some impatient seeds in a wet paper towel/plastic bag in a sunny window. This will determine rate of germination

well derfy.
Home depot plants are the pits. They may be fine in the greenhouses but when they get to the stores it's another story.

I agree that hygene is most important and so is air circulation when planting anything. Home planting and big greenhouse planting has to be different, just because of the size of a greenhouse compared to home planting.

Wouldn't we all like to start with new pots every year, but it's just not practical. In my 35 years of home growing I have never had disease or pest infection go through my greenhouse. I will continue to wash and sterilize and reuse my pots and trays.

I don't agree with no humidity lids for the home gardener. That is fine in a big greenhouse where they have misting systems. I've seen them in greenhouses too. They don't cover their seeds with lids, but they do have them on conveyer belts going under misters. That does the same thing as a humidity lid. It keeps the seeds moistened.

evelyn.
The humidity lid keeps the moisture in--in the soil, but because of the seed not being covered it can get dry just laying on top of the soil. A light and I stress light misting keeps the seed moist.

If you don't have the inclination or time to mist then cover the seed with a light coating of vermiculite.

My system works for me. I don't know my germination rate this year, but last year I had 241 seeds germinate out of 250. Not a bad rate considering the seed company said there was an 85% germination rate

sorry to hear about the quality of the plants at your local H D. I'd talk to the store manager. What many don't know is they are vendor owned not H D owned and there is a vendor rep on site at every store, or should be. That goes for perennials and annuals. As soon as the plants get past bloom, look old or tired or dying the vendor is supposed to pull and replace, They do in W MI. I have professional flower bed and container designers shop H D because they feel they get the best price and the freshest quality, not to mention the guarantee

I agree washing, sterilizing and reusing flats is the way to go for the home gardener. I brought up to our guide why not a chlorine wash. It's just more efficient to re cycle. They sterilize more for shipping across state lines purposes, something that a home grower doesn't have to worry about.

I have a timed misting system in my green house, mainly for propigating orchids yet in my 45 years of seed starting i have had problems with dampening off and there fore leaving uncovered, circulating air and keeping the surface dry has greatly reduced the problem

"but last year I had 241 seeds germinate out of 250 good for you

there is a vendor rep on site at every store, or should be. That goes for perennials and annuals.

So you're saying there's 2 reps at every store?? I doubt that. The vendor would go broke paying all those employees. Where did you get that info?
There might be 2 county/area reps at most.

I work there as their hort specialist.

He's there every day including Sat taking care of plants and helping with customers.

We also have two ladies from another supplier (Vegtables) that are their 3 times a week.

I can only speak for stores in our district.

Regarding starting form seed.
I took a packet of 22 seeds put them between wet paper towel, put in a baggie. and taped to a southern window.
germination was 32%. I have notified Burpee

For years, I had failed in all attempts to start Impatiens from seed.

This year, I got a Parks Seed Biostarter. Have been starting seed like mad for the past 2 months. Used the little sponge inserts that came with the unit (and have ordered refills twice more), put the Biostarter on a heat mat ... and have had over 95% germination.

I am still pretty unsure of the care of the seedlings once they are transplanted out of the unit into pots in the sponges. Any suggestions??

Thanks!

Falca
Northern Illinois

ive told this story a couple times but i feel like its relevant in this thread
i managed to germinate harvested impatien seeds just by filling one of those olive garden take out trays with potting soil. Sprinkling the seeds on top (didn't even cover them with soil) and misting the soil a couple times a day just so the surface is moist
I kept the take out container covered with the clear lid that comes with the container and kept NEAR the sun

I also used harvested seeds from prior year. Germination rate is 100%. The key is the freshness of the seeds. I have been collecting seeds from my impatients for next year use.