Long lanky seedlings (often called "leggy") with weak stems result from light starvation. You'll find many discussions about this problem and why window light doesn't work scattered throughout many of the forums.

The Growing from Seed forum has a great FAQ on the types of lighting needed and why. Linked it for you below.

Meanwhile, you may be able to save some of the plants by transplanting them now into deeper containers very deeply to just below the leaves but without additional light they will most likely just get leggy again.

Good luck.

Dave

Here is a link that might be useful: Lighting FAQ for seedlings

Your seedlings really need grow lights. Even cheap incandescent strips lights will work much better than window light. You can drape aluminum foil around the lights to reflect more light back onto the seedlings. I tried for a few years to start seedlings with window lighting only and I got the same results as you are getting. Once I started using lights, I did not have the problem again.

Thanks so much!

This is part of the reason I use starts from a reputable nursery. I have tried starting seeds over and over, only to have them fail due to not having a good set-up, then having to buy plants later anyway!
I'm spending about $20-30, but getting great locally grown starts that have a money back policy if they die.
I still start many plants in the ground after the last frost date.

Yeah but lettuce starts are like $2, which is what a head of lettuce costs!

I just got a 40W fluorescent and a 45W halogen bulb, and two aluminum clip-on lamps for em, plus a timer to give them 12 or 14 hours of light a day. I got light coming at them from both directions now, so that should help in the next two weeks as the frost risk passes.

{{gwi:34044}}

I like to watch the seedlings grow, I feel more connected. But its a shame so many are dying because I didn't know what I was doing :(

I do plan on replacing dead stuff with starts, so its not a total loss.

Halogen lights put out considerable heat. Make certain you don't cook your babies.

Certainly seedlings need plenty of light but I am wondering if what you are seeing is 'Damping Off'.

I use peroxide & water (1/10) in a spray bottle, then allow the top part of the soil to dry out between watering. After germination always water from the bottom, that IS where the root is. The root goes down about 4 times as far as the seedling has gone up before it even emerges.

Do a search on Damping Off to see if that is what is going on. Get some pics to look at too. Growing from seed does take some practice. It's a lot of work and requires patience too.

Starting seeds outside in a coldframe I don't seem to have that many problems any more and the plants are healthier.

Thanks, yeah I noticed that and clipped it to the rail on the blinds further away after I took the picture.

tomacco - Your screen name wouldn't have anything to do with the simpsons would it?

For your light problem I would head to a home center and get a fluorescent shop light for about 20 bucks. They come wired and ready to go with a pull chain and hanging chain. All you need to do is add two fluorescent bulbs and you are in business.

Here is a link that might be useful: Link To Shop Light

My screen name is from the Simpsons. I want to caffeinate tomatoes. Caffeine inhibits root growth, so I have to breed caffeine tolerant tomatoes. I got 100g of caffeine to do so, I'll add varying concentrations to the soil of trays of tomatoes and figure out the concentration that messes up about 1/2 the plants. Then I'll start with that concentration and select for those that grow better, increasing the caffeine, growth permitting, each generation. Hopefully I'll have caffeine tolerant 'maters in a few years.

Of course, I also have to determine if the tomatoes contain caffeine by extracting it. Then I'll just water with very cheap coffee and hopefully I'll have caffeinated 'maters in a few years. :D Its a very stupid project, but fun.

I don't think they are damping off. Light starved sounds right.

I already got lights, pictures above! One 40W fluorescent, and one 45W halogen.

There are no hard and fast rules and it's never just one thing. Seedlings grow just fine for me with natural light in a south facing room. There are plenty of windows. A small ficus calls this room home and is very happy. I've grown aquarium plants in this room with no artificial lighting as well. Along with lighting considerations, care must also be given to avoid over watering. Keep the sterile seed starting mix moist but not soggy. Also, apply dilute liquid fertilizer only after the second set of true leaves are formed. Some other things that are frequently overlooked -- seedlings tend to be less leggy if there's some natural breezes and good air circulation. My winters aren't too harsh so I set seedlings out on a bench in bright partial shade to keep them pre-hardened during daylight hours. Wind hardening is part of the overall picture.

If I didn't have this well lit room, I would use cheap shop light fixtures with full spectrum (natural sunlight) bulbs (5500-6500 Kelvin). I'd run them on a timer for 12 hours on and 12 hours off to simulate a normal day at the equator. And I'd run an indoor fan periodically.

Thanks for the feedback, I got some shop lights and I'm gonna setup a proper grow rack.

As others have said above, the shop lights will do wonders for your seedlings. Keep the leaves within an inch or two of the lamp tubes as they grow and give them maybe 14 hours of light per day.

Also important is to start your seeds in something which contains no fertilizer and do not feed them until they have one or two sets of true leaves. Then only feed them sparingly and infrequently. I have had disastrous results with potting soil. Seed starting mix is different and is what you need.

Those are the two most important things you can do to get thick stemmed, bushy seedlings. One more thing, if it is possible in your circumstances, is to give them cool temperatures after they emerge.

Jim

Although it is extremely important to have lights very close to the plants (I let mine grow up between the bulbs) and to keep the air circulating with a fan, I have a comment about the the particular plants that you are having "problems" with.

Broccoli, Cauliflower, Lettuce, and Cabbage, are all plants that grow from a crown rather than a stem or vine (like tomatoes, beans or squash). Crowning plants will naturally fold over to the first set of leaves and grow their crown from there, in contact with the soil. Flowers that do this include petunias and impatiens.

So, though you most certainly do need additional light, The plants that you have are behaving exactly as they should.

Kay