Celery is really picky about soil temperatures. You can't get your lights all up on them when starting them like you do for peppers and tomatoes because of how temperature sensitive they are. They like soils in the 60-70F range. The seeds don't tolerate drying out, either, but you've said you're keeping them moist. Light is needed for germination, too, so I hope you didn't plant them too deeply (1/4-1/8 inch covered at most).

It's a very picky plant that requires a long growing season while liking things cool, but not freezing-cold. Good luck. I've only occasionally had garden-grown celery, myself.

Someone posted this great link to temperature effect on germination. It shows that celery won't sprout above 86ºF. (30 ºC), and perfers 68 ºF (20 ºC).

Here is a link that might be useful: Germination Temperature

It's a bit difficult to comment on your planting dates, because you don't give us your zone. I know that Australia and New Zealand have growing times that are more or less opposite from ours, but still would be nice to know when you plant your veggies, and soil temps, etc.

I planted some celery about 5 years ago - it was described as "improved" Utah (something), and it has been with me ever since, as I let some go to seed. Fresh seed works well, and harvested celery seed is great for an addition to the spice shelf.

Granted, my zone is quite warm in winter - but perhaps the seed was nice and fresh as well.

In our zone 10 - California, we plant celery in Aug, Sept, Oct and Nov., along with other crops - such as broccoli, cabbage, lettuce, etc., - cool weather crops, and celery is very happy with our mild winters, liking lots of water and can withstand shade when the weather becomes warmer.

About your planting method - just a thought - does your container have good drainage? What about light - are you growing inside? Under light? No mold?

These are all factors in growing from seed. Most vegetable seeds like warmth to around 70 degrees if possible to germinate. Good air circulation - once seed sprouts, remove the dome - to prevent mold formation from too much humidity.

HOpefully, your seed is still viable. To test some - place a few seeds in a damp paper towel, place inside a plastic bag, keep warm - and see if they sprout. If not, then seeds are too old - try another supplier.

Sorry - can't help any more than that with the information given.

Keep trying!

Bejay

I grew celery from seed a couple of years ago and it did very well. It does need to be started indoors well before last frost, since it requires a long growing season.

Make sure you remove the domes for an hour a day to air out the pots or cells. You could also try drilling small (1/8 inch - 3 mm) holes in the domes; that helped me to germinate plants that like cool germination temperatures. In that case you may need to mist them more frequently to keep the soil moist.

I'm a new gardener, started last year, and celery has sprouted for me both this year, and last.

What I do is moisten the seed starting mix in a large bowl, I then fill the containers with the mix and press it down a bit. Then I sprinkle the seeds onto the soil. I do not cover the seeds with soil at all. Then I bottom water the entire tray and make sure the mix is thoroughly moistened. I then use a spray bottle to mist and moisten the seeds from the top. Then I cover the tray with a plastic dome and keep the temps at about room temperature, but make sure not to make the seeds too hot. I do not turn on the lights at this point because the lights plus the plastic cover can make for quite a hot environment. I think natural room light is enough for the first few days. After about 2 days I remove the plastic cover and from that point I mist the seeds 3-4 times a day while keeping them under lights.

For me they start to sprout in about a week, and will continue to sprout for the next few weeks. After they sprout, keep the lights close, maybe an inch or two from the soil.

I think the trick is to not cover the seeds with soil, so they have access to light, and to keep misting.

I've always heard celery was difficult to grow from seed and it's caused me to shy away from growing it. I went with loveage instead (a cousin of celery), and I really hate the taste of this plant. Good thing hubby likes it.

This year, on a whim, I bought a three pack of celery when I bought my broccoli and cauliflower. The celery looks to be several weeks along. I popped them in the ground and check on them every day. The temps have been perfect for them so they are growing a little each day - one more than the other.

After reading what everyone has to go through germinate celery - no thanks, just don't have the space. But if I have another mild spring, I'll think about planting it as a seedling.

I start celery every year. Just sow it on top of pro-mix in a flat, don't even cover it with soil and mist it, slap a humidity done on it at night, and let 'er rip. I had excellent germination on it this year. I grow it in a g'house so don't use light supplementation.