I know about growing annuals in general

how is the temperature, could you keep the room cooler? that would slow things down,

not sure about pinching if it is the actual flower stalk, I know they reflower after pruning, at least well-fed elatior-perennial types should do,

so perhaps you would destroy the second set of flowers by pinching

Frances, I'm assuming you're are referring to growing the annual Delphinium, which is now Consolida? They really take off like rockets in early spring. Apparently they resent transplanting. Maybe if you transplanted them into larger sized pots now, it would definitely slow them down and delay flowering while they experience transplant shock and try to adjust. I'm just guessing. But later it could also mean they will fair better when you do plant them outdoors. I've made the same mistake and started plants inside, under lights much too early, only to have them blooming in my basement with no insects to pollinate their flowers. Best to wait until exactly 8 weeks ahead of the date you plan to put them in the ground. Maybe because Consolida has such a fast growth rate starting 6 weeks ahead of planting out might be better. It would be less strain on the plants if they were transplanted outside, before they started going into flowering mode.

Thanks for your thoughts! Jay, I do grow del[phinium consolida (larkspur) but I winter sow and direct sow them. What I'm talking about here is delphinium elatum - I'm growing the varieties Blue Bird, Blue Jay, Black Knight, Guardian Blue, and Belladonna Bellamosum.

Reducing temperature might help - though a bit tricky, since I'm growing them inside our house! We don't have a garage or basement, so my plant lights are set up in my home office. We usually turn the heat down to about 60 at night, and have it at about 65 during the day, but I can ask DH how he'd feel about slightly lower temps!

i agree on massaging temps rather than light to slow things down ....

can you move them to the basement.. rather than freezing out the whole house??

bottom line.. take copious notes for next year ... new lights. new methods ...

maybe even try a new cell pack of seed now... see if you can get them ready on a new time schedule ...

ken

Wow! Sorry they're growing too fast, but you have me re-thinking all my fluorescent lights!

I would pinch out the bloom stalk and consider moving them outside to a protected spot in another two or three weeks. If you get a string of above-freezing nights and they have a chance to harden off for a few days, they should then be able to handle a few light freezes, their growth will slow, and you won't have to worry about lugging them in and out. I'm not sure when they would bloom though...

Have you considered starting them in August and just letting the seedlings overwinter outside?

Thanks for your thoughts! I AM taking notes - this really is a game changer for my seed starting. I have never seen results like this! I'd highly recommend replacing your fluorescents, katob. These LEDs are great. Better from an environmental standpoint, longer lasting, no noise at all, and the light is really natural and beautiful, not harsh like the fluorescents. And obviously, the plants love them!

I wish I had a basement or mudroom to move them to, but no, in our tiny house is my only indoor option. DH is very patient with my plant messes, but I don't know that I can ask him to freeze for the sake of my delphiniums! But I do like the idea of trying to harden them off soon. Hopefully our temperatures will settle down to a 40s-50s daytime soon. Late March might work.

Starting some new seeds is a great idea! I'll definitely do that! I winter-sowed some of my extra seed, but I like the idea of starting some in August and letting the overwinter outdoors.

Thanks everybody!

I had a similar experience with LED lights. I grew two micro tomato varieties, both of which were supposed to reach 18" in height, but were 4' tall under the LED's.

Linda