Rick, I thought I'd jump in with some thoughts about this. Spinach bolts to seed due to several factors: stress, temperatures, and daylength among them.

If you have overstressed the seedlings, with extremes of temperature, moisture, or by crowding them or their roots, they will bolt.

If the daylength is too long, over 12 hours, this will also tell the plants that it is time to go to seed. Short days under 10 hours tell the plant that winter is coming, and it should make a nice rosette of leaves.

Temps in your basement sound decent for spinach, but cooler would probably be better.

I would suggest that you direct sow some spinach in the garden now or within the next couple of weeks, and see what that does for you. Should give you a good crop of non-bolting spinach yet this fall, assuming we don't have any extreme heatwaves in Sept or Oct. And, it should overwinter for you, although might require some protection (straw, etc) and give you a spring crop before bolting also.

Hope this helps a bit. Others may have different ideas/opinions that might help, too, hopefully someone else will post as well.

Dennis
SE Michigan

spinach is a very difficult crop for most areas. The best way to grow it is over the entire winter. It should do ok for you. it should survive and you crop it in the spring.

you plant the seeds probably now and harvest in the spring.

there are some web sites discussing growing spinach do a google search.

of course the pacific north west is where the seed crop is grown because it does well there.

I have given up on it and now grow swiss chard. really tasty if you pick some good varieties. It grows so incredibly easy compared to spinach. you can slice off the stem and eat the leaf portion only just like spinach. of course do not throw away the stem. they are great to eat but you can cook them separate for a different texture.

However, I just cook it all together. I am not trying to emulate spinach.

But what if you like *uncooked* spinach. How does swiss chard compare?

I'm also starting spinach seedlings. But I suspect that the windows they are in are probably too warm. Dunno about the length of daylight.

I sow spring spinach in the garden in mid to late September. In March I remove yellowed, ragged leaves and side dress with dried blood (nitrogen) and compost. I'm soon harvestin lots of spinach.

I also try sowing spring spinach in early March. Sometimes it makes it, sometimes we get an early hot spell, and that's the end of it. But the fall sown spinach always yields a great crop.

That explains it. I had no idea Spinach was day light sensitive. I leave the fluorescent lights on 24/7.
I will have to re-try with light only 9 hours a day.
Thank you so much.

Raiderrick,

Spinach is very cold hardy. Just plant it outside from seed right now. If you put a cold frame over it when the weather during the really chilly months (December, January, February) you should be able to harvest it all winter if you have a fairly big patch of it. Then in the spring it will take off growing again very early on.

BTW, if you are interested in growing spinach and other salad greens through the fall and winter you should check out The Four Season Harvest by Eliot Coleman.

I planted it 4 days ago here in zone 4 and will enjoy 4 to 5 weeks of fresh spinach next spring. It will be up in about 10 days and will give it a shot of fish emuulsion. Winters just fine, snow or no snow.

I started my seeds inside and under lights and kept under lights 16 hours a day some did good and some did not eventually make it. I moved outside not under direct sunlight and most are doing very good. However, I had two plants bolt. I assumed moving outside to another temperature may have done this, I kept the watering method the same. Any thoughts or comments on this? I am in zone 8

spinach is both day length sensitive and heat sensitive

no plant should receive or need 24/7 light. Give them time to rest in the dark just like animals and people