Check out these FAQs here:

I'm new to growing from seeds so how do I get started?

OK,my seedlings are growing,now what do I do?

Do I need lights for starting seeds?

What Types of Containers Can I Use for Seed Sowing?

They should answer all your questions. ;)

Dave

1. The flat trays with many small pots. I don't like peat pellets.

2. "Do you transplant your seedlings once the cotyledon pops up?" - No. You only transplant plants when you have to -- when they outgrow their container or they're too crowded together. Transplanting is a shock to plants, so you avoid it insomuch as you can.

3. As soon as the plant is out of the soil, you want light to be there ready for it, and lots of it.

4. Bottom, absolutely. Wet stems and leaves are much more prone to disease. So is having a wet soil surface more prone to fungus. Bottom watering is more efficient and healthier.

Question for Karenrei - in terms of bottom watering... I have some seedlings in the 72 cell flats. Do I simply bottom water by lifting up the cells and pouring the water to the bottom of the tray? That seems logical but I fear it won't get the soil wet enough.
Thanks!

Thanks for your responses. Great stuff! :) Okay then, here's what I'm planning to do. Please shout warning if I'm off-base.

I'm going to put a half and half mixture of potting soil with vermiculite into my 2" high 72 pot flat. I will fill each pot so there is only a 1/2" to the top. I'll do that so light can reach the plants better. Each pot will get one seed.

I will water from the bottom and cover the seeds with plastic until they start coming up. At that point I will remove the plastic cover and turn on the grow lights.

Once my plants look strong enough I'll harden them off. I will not pull them out of the pots until it's time to put them in the actual garden. That will be their only transplanting moment.

Sound good? ;)

"I will fill each pot so there is only a 1/2" to the top. I'll do that so light can reach the plants better."
I think it would be better to fill the cells to the top. The seedlings will have more room to spread their roots with the cells filled all the way. Also, I don't understand why half filling the pots will allow for more light?

Jon

Question for Karenrei - in terms of bottom watering... I have some seedlings in the 72 cell flats. Do I simply bottom water by lifting up the cells and pouring the water to the bottom of the tray? That seems logical but I fear it won't get the soil wet enough. Thanks!

Yes, just lift up one group of cells (no need to lift it all up) and pour in water. Trust me, you can get them as wet as you want, anything from dry as a bone to a rot-your-plants-in-an-hour swamp. All that matters is how full you fill it.

I'm going to put a half and half mixture of potting soil with vermiculite into my 2" high 72 pot flat. I will fill each pot so there is only a 1/2" to the top. I'll do that so light can reach the plants better.

I agree with Hatchjon. I'll also add that loose soil (which is what you should fill them with -- don't manually compact it!) will get compacted somewhat on its own as you water. So if you start them at only half full, they'll end up at 1/3 full or so. Go ahead and fill them up full to give your little plants all the room they need to grow. :)

Apart from that, sounds good!

A couple of possible problems that are addressed in the FAQs here.

I'm going to put a half and half mixture of potting soil with vermiculite into my 2" high 72 pot flat.

Not potting soil. Using potting soil will almost guarantee you damp-off problems. Why potting soil is NOT used but soil-less mixes are is explained in detail in the FAQ I linked for you above. Soil-less potting mix or better yet, sterile seed starting mix is used for germinating seeds. They come with vermiculite already added.

I will fill each pot so there is only a 1/2" to the top. I'll do that so light can reach the plants better. Each pot will get one seed.

As others have said that doesn't improve the light any. If you use only 1 seed in each containers you will have empty cells because not all the seeds will germinate. If you want a higher rate of germination place at least 2 or more in each. This too is explained in greater detail in the FAQs.

And if you mix varieties in the same tray you will get all sorts of germination times. There are many discussions here about how to cope with this problem. Once the first ones germinate they must be removed from the tray and uncovered while the rest remain covered.

Once my plants look strong enough I'll harden them off. I will not pull them out of the pots until it's time to put them in the actual garden. That will be their only transplanting moment.

Very few things can grow in the 72 cell flat to garden size without getting root bound. They also tend to get long and leggy with weak stems and so need to be deeply transplanted at least once.

Most every experienced seed grower transplants the plants at least once to larger containers - larger cell packs, foam cups with holes in them, small 3 or 4" pots, etc. Here in the greenhouse plants are transplanted 2x before they are ready for garden planting. How to do this is discussed in detail in the FAQ "OK, my seedlings are growing,now what do I do?"

Plants that have been transplanted at least once have much stronger toot systems as a result and will tolerate hardening off and garden transplanting much better - that's why pro growers do the interim transplanting.

Good luck with your plants.

Dave

It takes time to help a newbie and I really appreciate your sharing your knowledge. It's a huge help. Yeah, it turns out the "potting soil" I used is Ferry-Morse Seed Starter Mix. I mixed that with vermiculite 50/50. A nurseryman here told me to mix potting soil with some perlite half and half with vermiculite and the Ferry-Morse seemed to fit the bill. If I've overdone the vermiculite, then oh wow, I've already made the mistake.

I'm glad you shared about planting more than one seed. I'll go back and add more tomorrow when I get my hands back in the soil. :) Today I only planted one in each pot. I thought they looked rather lonely. *grin*

Dave, what you're talking about with the foam cups with holes in them, small 3 or 4" pots - can I just get foam coffee cups and use those? They're good and cheap.

I'm watering from the bottom and it seems to be taking a while for the soil mix to wick the moisture up to seed level. I'll check again in the morning.

What you've said makes good sense. Understanding the "why" of things helps. Thanks.

Well, how many seeds to plant in each is a matter of personal preference. If you plant more, you may want to have some spare trays around for "thinning out" into. In general, I do multiple of tiny seeds, or seeds I'm uncertain about, but often, with seeds that I know have very high germination rates (like tomatoes, for example), I'll just put one. I've had enough experience with putting three tomato seeds in each planter pot and ending up with three times as many tomatoes as I have room for that I don't care to repeat ;)

Thanks Karenrei. That's good to know and will save me some trouble.

At one of the links Dave shared it says:

"Sowing seeds: Fill containers,allowing an inch or so from the top for easier watering, and moisten well. Allow excess water to drain, medium should be moist,not soggy. Press the medium down lightly to eliminate air pockets. "

It sounds like I should thoroughly wet the soil prior to planting my seeds. I bet that's why my soil isn't wicking from the bottom very well yet. It just needs a good soaking first. I pulled this together in a hurry which is why I'm missing important details I think. We're building the square foot garden planters and doing everything at once. Not recommended! :)

Sure the 8 oz. foam coffee cups works very well. Just be sure to poke holes in the bottoms of them and a couple near the bottom on the sides too for drainage. And then just write the name right on the cup.

If you needed bigger containers later on for some reason you can go to the 12 or 16 oz. plastic drink cups. Some even use the paper Dixie bathroom cups for small things and there is always newspaper pots too.

On the multiple seeds in each cell bit - any extras that do sprout can either be transplanted out or just snipped off with small scissors if you don't want the extras.

I don't think adding the extra vermiculite will hurt anything. Just extra $$. We grow many things in the greenhouse in straight vermiculite. But you will have to feed them once they develop true leaves. No nutrients in the FM mix or in the vermiculite. Use a 1/4 strength diluted mix of any good liquid fert.

And yes, definitely wet your soil well before planting. ;)

Dave

Thanks digdirt for the info on the FAQ section. For as long as I have been on these forums, I never knew there was a FAQ section offered for each. Learn something new everyday from y'all! Thanks again!