one tray - varying germination speeds

I planted 6 different kinds of seeds with similar germination requirements together in a one tray with individual cells (in each cell I planted 3-4 seeds of the same type). Despite the fact that the seed packets claimed the different types would all germinate within a similar time period, my seedlings are in fact making rather staggered appearances. The perennial dianthus was the first to appear, tall ageratum second, and only today are some other types beginning to come up. The laurentia "sophia", however, has not yet shown any signs of life. It's only been a week - everything happened faster than I had anticpated.

At what point should I put lights 2" above the tray? When do I start taking off the cover for parts of the day? How do others deal with these types of germination differences?

Thanks in advance for input!

Almost 4 weeks later, and I have very little life from my Laurentia (Blue Star) either. I think there is something I'm missing on how to germinate these seeds.

Some seeds require being planted above the soil and just pressed into it. Make sure the ones requiring light to germinate are close to the surface and ones requiring darkness are covered.
You may have to do some research to find out how to sow the seed, but it is important to know. I found that most of my failures of seed germination was due to this factor when I first started planting and growing from seed.
I could never grow tithonia Mexican Sunflower until I learned that these seeds should not be covered with soil.
I am trying growing under lights for the first time this winter. I am anxious to see how it works out and can't offer any info on when to lift the cover on them. Next year we will both probably have learned enough to be semi-experts at it. LOL

I have learned the hard way never to put two different types of seeds in the same container because they always germinate at different rates, and then I am left with the problem of when to remove the plastic. If I leave it on for the one that hasn't popped yet, then the one that has will be exposed to too wet conditions and filtered light and get leggy. If I take off the plastic, then the seeds that haven't popped yet will get too dry and I either have to mist several times a day or lose germination.

I am actually struggling with this problem now, and had already come to the conclusion that I will only plant the same seeds together. Tigerlily is absolutely right.

This year, I decided to work with large flats that hold well over 100 cells. I am running into the problem of having some types of seed already up and sprouting, while others still haven't germinated. Since I have only done a limited number - those that needed to be planted 10 - 12 weeks prior to the last frost, I am switching to smaller flats for the big rush, which is 6 - 8 weeks prior to the last frost. Tomorrow, I am going to buy some smaller flats that I can fit into my trays.

There may be a way to get them to actually germinate about the same time, but it probably isn't work the heartache to keep experimenting. If you are lucky, someone else has already done this for you and can give a more specific answer on specific seeds.

pennefeather-if you have some up already, then take the cover off and put enough dirt over the seeds that haven't germinated and just individually water those enough to keep the soil moist. That should help

I have always done my seeds in smaller 6 packs and not a whole flat of the same seed. I guess the answer depends on the number of seeds of each type you are starting and the space you have to work with. Right now I have some seeds that need the heat mat and some that don't. I only have a few 6 packs in each flat. I move them around to different flats as the need arises, dome or no dome, and the different height of the light as some plants grow faster then others. I have 4 shelves that I can very the height of the lights. and 8 spaces for flats. I also move around 6 packs according to their water needs.

This is just the way I do things, it works for me.

It sounds like smaller containers are the way to go. I've been using a seed-starting set from Gardner's Supply that comes with a dome and capillary matting for watering from underneath. I had great success last year, but I only tried a few kinds of seeds, so having them all in one seed-starting tray wasn't an issue. This year I'm more ambitious and have selected a large variety of things I'd like to sow. I've been collecting yogurt / cream cheese containers and sterilizing them. Are there better methods out there for a beginner?

Tigerlily,

Thanks for the advice. I have been trying to do this, but I realize that I will just make my life easier by getting smaller inserts. I just ordered 100 of the 1206 last night.

When I was planting last year, I only had three or four types of plants. This year, its about a dozen. I kept seeing more and more things that I wanted, and I needed to justify the cost of my shelving and lights. Even now, with a full schedule, and more plants that I am going to have room for when they germinate, I find myself still getting just one more thing. I may need a second set of shelving and lights!