Broccoli seedlings are way too tall but thin and weak

Question

I just started sowing broccoli indoor this month and after a week or so, I saw this

They are almost 4 inches long but cannot stand straight. Did I not push the seeds in deep enough? Or is this kind of broccoli like that? I bought from a Chinese grocery store. They are so long and weak, some started to break now.

But they seem not ready to plant down the outside garden though, right?

UPDATE 1

According to the article, Leggy Broccoli Seedlings, looks like it's lack of light or too hot. I don't think it's lack of light because it's next to the window and it's sunny all day. The temperature is 70-85 range. So maybe it's too hot in the house?

Answer 1

This is definitely too little light. Are you indoors? A greenhouse? No they aren't ready to be transplanted. If they are indoors by a window that is just not enough for light. You need to get a real grow light to start plants indoors. Those seedlings will strengthen if you get a real grow light. We've got lots of info on lighting on our site.

That window is just not enough light. As long as the temp is below 90 degrees F plants will do just fine.

If your plants have never been in the sun you will have to acclimate your starts to the sun before they ever feel sunlight on their leaves. Otherwise they will burn. Acclimating thickens the epidermis to protect the other cells from the radiation of the sun. Sort of like our melanocytes. Lots of answers about that as well on our site.

If you have a covered patio or deck I would definitely put them out of doors. What are the night time temps? Good time to start if you want to transplant in your garden.

I also rip that thin fabric off, or cut it off before transplanting. I usually up pot into a 4" first, allow roots to fill and make sure the starts are used to the amount of light, wind before planting in the prepared beds of the garden.

Have you used fertilizer? That might also be why they are so elongated. Fertilizer helping them grow when they are unable to make enough food for themselves causes plants to elongate and thin leaves in an effort to reach more light. Don't fertilize until planted in 4" pots. Sparingly.

Hopefully you are using bagged potting soil. Growing in pots one has to use potting soil. They will be just fine transplanted into the garden soil.

Answer 2

As noted, you found your answer on the net; too little light and too warm. When I started seeds with some success . It was in a garage at roughly 60F. I used 2 -40 watt growlux and 3- 100 watt incandescents mounted in the fluorescent hoods. The light fixture height was adjusted to a couple inches above the plant- yes some leaves burned. 100 watts were used more for the color than the lumens , that is, a 40 watt incandescent is nearly all red and yellow. Today much better lights are available , LEDs etc. It may be easier to find spectrum information for aquarium lighting than in gardening literature. I don't think it is worth doing anything with your sprouts. My point is a lot of light is necessary.

Answer 3

Broccoli like any brassica is very hardy- so not much warmth is needed- about 10 to 15c and lots of light when they emerge, place next to a window still and turn them 180 every day- I wouldn't keep them indoors for no more than 5 days and start to harden off to go outside straight away, the jiffy pots you've got them in will show you when to plant up or pop into new pots 3-4inch ones when the roots start to show through the bottoms and possibly the sides too- plant outside about 9 to 12 inches apart depending on variety and net to keep the birds away- water and feed every month the rest is easy. (the technical term for this is etiolation: the process of rapid growth, without the production of chlorophyll, that occurs in shoots kept in the dark. Etiolated shoots are long, thin and pale, and their leaves are very small.)hope it helps