So I've started all types of plants, tomato, pepper, eggplant, squash, brassicas indoors. I also grow lettuce 100% indoors under LED grow lights. Lettuce does well for the most part. I tried growing spinach and it sort of gets stemmy or goes to seed very quickly. Doesn't get large leaves at all. I've tried different varieties and same thing.

Has anyone tried growing spinach for harvesting under led grow lights and had success?

Spinach usually bolt (go to seed) when days start getting longer and temperatures become warmer in the Spring. According to my dated book here they start to flower when days last at least 14 hours and temperatures are over 75F.
Cool season cultivars tend to get taller and and with few leaves, exactly like you saw.

What to do? You can t-r-y one of the bolt-resistant cultivars developed over the past decade: they will bolt eventually, but will do so later in the season. According to literature the two most bolt-resistant cultivars are Spinner and Correnta.
Another thing to do is to try and keep temperature and lighting under control. If you can keep temperature under 80F or so you have good chances of success with one of the bolt-resistant cultivars. You should also set the grow light timers to provide an even 12 hours of light and darkness every day.

That's all I can think of: I've never had much success with grow lights myself.

That's interesting! Never would have thought too much light would trigger a plant to bolt. The temperature is not a problem. However, I do leave the lights on at lot longer than the 12 hours. Lettuce doesn't really care how long the lights are on. I have good luck with various lettuces, bok choy, and radishes. I'm trying baby carrots now for the first time. Tops are growing well, will have to see if the root forms. I'll start another batch of spinach and set the timer for 12 hours. Thanks for the advice.

thommesM said: I'll start another batch of spinach and set the timer for 12 hours.

I am searching the forum for indoor spinach advice. Did anything work for you when you adjusted the light schedule? My seeds germinated fine, the sprouts looked good and strong. I replanted them on 12/5 and they had some growth initially, but have stopped. I'm not sure if my light is too strong, too dim, on too long, not on long enough, too close, or not close enough. Currently the light is 12 inches from the tops with a 13 hour on daily schedule.

Can you post pictures of your set up?

I'm trying spinach, lettuce and a couple other things with 12 hour lights. Just sprouted, too early to say.

LyraLu said:

I am searching the forum for indoor spinach advice. Did anything work for you when you adjusted the light schedule? My seeds germinated fine, the sprouts looked good and strong. I replanted them on 12/5 and they had some growth initially, but have stopped. I'm not sure if my light is too strong, too dim, on too long, not on long enough, too close, or not close enough. Currently the light is 12 inches from the tops with a 13 hour on daily schedule.

Not really. For some reason I get small leaves and in a couple of weeks the plant bolts. Same happens to a couple of varieties of basil that I grow inside. The regular Genovese? and the red variety do well but the lemon and cinnamon varieties seem to bolt super quick.

sallyg said:Can you post pictures of your set up?

I'm trying spinach, lettuce and a couple other things with 12 hour lights. Just sprouted, too early to say.

Sorry! I just saw your reply. I'm still getting my bearings on the forums. I gave up just yesterday, but here's a pic of what they plants looked like.

@LyraLu

I have certainly had cilantro and maybe some other things end up like that
12 inches from the light .. and what kind of light? I use fluorescent tubes.. and most say have the soil surface within a few inches.
If they were growing well, the pot would be ok.. as it is now the pot is kind of big, so I would be careful not to water too much.
I won't say I'm expert at this, given my track history! My past tries have been with 16 hours of light as that is what tomatoes etc want. I'm doing 12 now to stay in the 'short day' range..

sallyg said:@LyraLu

I have certainly had cilantro and maybe some other things end up like that
12 inches from the light .. and what kind of light? I use fluorescent tubes.. and most say have the soil surface within a few inches.
If they were growing well, the pot would be ok.. as it is now the pot is kind of big, so I would be careful not to water too much.
I won't say I'm expert at this, given my track history! My past tries have been with 16 hours of light as that is what tomatoes etc want. I'm doing 12 now to stay in the 'short day' range..

I have a Groplanner full spectrum LED (150 Watts 756pcs).

Here's a planter, half spinach and half arugula. I've been leaving the light on 24 hrs. a day. It's in a greenhouse, so there's more light during the day. The spinach bolts so I harvest it when it forms a head.

I would sow the spinach outside.

Why 24 hours?