Another shot of the long broccoli...

More broccoli

You need that light as close as you can put it to the plants! You also need a fan to keep the stems strong! Go easy with the nitrogen fertilizer... I use woodash and kelp with a little compost for my seedlings! Watch out with the compost tea, the bacteria/fungus killed my seedlings, don't learn the hard way!

Light as close to plants
Fan to strengthen stem
Little Organic fertilizer
You're on your way to success!

Best of luck,
Joe

how far apart are you light tubes. how long are the lights on per day.

Mine grow pretty good and the other difference I notice, is I give my seeds more room. It looks like you have two seeds per block. The space I give my plants is one seed per 2 of your block sizes. For me, broccoli is finnicky so I give it more space, so transplanting is easier. I don't see how that could effect the legginess, but that's the only difference I can see at this point. Also, I thought broccoli was best transplanted once true leaves appear. Maybe you started them too soon- maybe they need to be potted up. Those are the only suggestions I can come up with.

I start taking my broccoli seedlings outdoors whenever possible as soon as they germinate. I do bring them inside from storms and most rains. I also start them so that I can transplant them outdoors at 28 days max. I also add more 'soil' in the pot to better support the plants.

I start several seeds in smaller cells, and then divide and transplant them deeper in individual pots as soon as they have a set of true leaves. If you can keep them cooler, I expect that would help. Mine move to the bottom shelf of my lights after they are transplanted, which is at least 15 degrees cooler than the top shelf.

I have had great luck getting them started the past few years - but I can never get them to put out large heads once they are growing in the garden.

I agree that broccoli like cooler temps. Their favorite temperature is about 45 degrees :). Outdoors under cover (like, on a porch) seedlings will be hardy down to at least 26, maybe lower.

I start mine without heat or lights, and move them outside soon after germination. I don't worry if they get leggy like the ones in your pictures; they make fine, happy plants anyway.

I don't understand why everyone gives woodash a bad rap.. People pay a buck a pound for azomite,etc.. For free, woodash contains lots of minerals... Plus you are using such a minute amount it is not going to affect pH... I been using woodash for years and my pH stays a consistent 6.5! What's the big deal?
You might need a brighter light!...
Put a fan on them!
You'll be in the right direction!

Best of luck!
Joe

The thicker the stem the bigger the head.
Plant deep on the stem each time you pot up. The plant will form more roots and get a thicker stem.

veggiecanner GOOD TRY but not correct.

I'm a newbie to growing from seed but I have already noticed a big difference in my broccoli seedlings growing better once I moved them out into the unheated parts of the greenhouse. Those that stayed in the house under lights longer and those that I kept in the heated part of the greenhouse with the tomatoes and basil are leggier and not as healthy looking. Once germinated they like it cool and should respond better to it.

I have an inner hoophouse inside the greenhouse that gets most of the heat. Took me a little while to figure out that the lettuce, cabbage, broccoli and cilantro all do fine and in fact better if left outside of it. I know they're cool season veggies but for some reason I still felt like they should be kept warm when young. Not really the case.

I strongly suspect that temperature is the problem. Broccoli, once the seeds germinate, prefer to be in a very chilly environment. Yes, they can tolerate freezing temperatures nicely.

When grown in toasty conditions, they appear etiolated, leggy.

Thanks guys! I feel like I've learned a lot! I think temperature is my big problem. I've got this great, indoor environment that I keep warm bc I always thought that was best for young seeds. I think the broccoli just needed to be transplanted outside a LOT sooner and given a different treatment from my other seedlings. I'll also try potting up in the future and using a fan!

Thanks!
--Shepherdess

It is my understanding that a root can only form from a node on a plant. A node is a bud that can become one of three things. A root, a leaf, or a flower. The conditions surrounding the plant will determine what that is. If it is dark, moist, and there is soil present, it will turn into a root. If There is sunlight, it will be a leaf, side shoot, or flower. (much more complicated, but trying to keep it simple). In this case, if the broccoli plant is planted deeper than the crown, but not as deep as the first leaves ( which is a nodal area), then there is nowhere for a root to come from. If it is planted deeper than the first few leaves, then it can possibly form roots along the stem. This is a major principle of vegetative propagation. It is also why the late season tall brassicas that have fallen over will root at a nodal area when it has come in contact with darkness and soil. Hope this clears up any confusion without making it worse!

It is my understanding that a root can only form from a node on a plant. A node is a bud that can become one of three things. A root, a leaf, or a flower. The conditions surrounding the plant will determine what that is. If it is dark, moist, and there is soil present, it will turn into a root. If There is sunlight, it will be a leaf, side shoot, or flower. (much more complicated, but trying to keep it simple). In this case, if the broccoli plant is planted deeper than the crown, but not as deep as the first leaves ( which is a nodal area), then there is nowhere for a root to come from. If it is planted deeper than the first few leaves, then it can possibly form roots along the stem. This is a major principle of vegetative propagation. It is also why the late season tall brassicas that have fallen over will root at a nodal area when it has come in contact with darkness and soil. Hope this clears up any confusion without making it worse!

I'm seeing phos. deficiency in the leaves. Yep, agreed, the little buggers like it cool and won't like hang'n with the tomatoes and peppers.

Figure out a way to insure there is no light competition (shading) among the leaves in the flats.

I too haul my cool season stuff outside when it's warm enough to get direct sun or bright, indirect light, does wonders. Gotta cold frame?

If your cabbage is doing well, then I would suspect your broccoli variety/type of seeds -the two usually behave similarly for me.

~emmers