Oh yes, to add... this variety supposedly matures in 90 days. (Faster-growing than some.)

I start mine under lights and transplant after frosts. I have found that harvesting later in fall yields a sweeter taste so I wait till after a hard freeze to harvest. They are REALLY heavy feeders so fertilize well. I don't use any pesticides so mine get a little nicked up but not bad. I also use a 90 day seed but the sprouts get bigger if you wait. FWIW

Up here in the frozen north, you need to get them in the ground by first of June at the latest, or they won't have time to grow to the size they really need to be to make a proper crop. Because of their growth pattern, there isn't any danger in planting them too early, unlike, say, cauliflower which can "button" if it is too cold while the seedling is small. But you can plant them too late. I guess if you planted well-established transplants by July 1st and REALLY babied them, they would still be big enough to give a good yield, but personally I don't want to chance that.

The advice about planting in summer to fall is for the warm winter folks, Zones 7-10 basically.

My collars have gone to seed in late July & seedlings came up.
I watered them when I watered the parent collards & some made it to picking size. They lived though the winter here in zone7b/8a.

So... I hope I am not misunderstanding. Is it possible to start them indoors very early and HARVEST them in early summer before the heat of the summer?

Not in my experience. Perhaps others have had different results, but I've never had them begin to attempt to form the sprouts until the autumn. I don't know if photoperiodism is involved, or if sprout production is influenced by temperature, or just the fact that any of the varieties out there are rated a minimum of 90 days, and most significantly longer than that.

They don't care about heat, at least not the kind of heat we have in northern climates. I'm sure they would probably suffer and perhaps die in the heat of an Arizona or Texas summer, but they suffer no ill effects from our heat waves here in Michigan.

Same experience here.

Plant them in spring and you will get a fall crop. I tried getting them in the sping and that was impossible. I planted in summer for a fall crop and got a couple of marble sized sprouts before the snow fell.

Wisbill:
Started my Seeds, Falstaff 110 days, under lights, and transplanted out 5/12/12. The bed they are in has rampant Brocolli, Cabbage, and Cauliflower happening. So how do I fertilize the sprouts? N=? P=? K=? I am discovering that I don't really understand fertilizer very well. My sprouts are purplish, rather like the purple cabbage, and about two feet tall just now.

What does FWIW stand for?

For what it's worth.

I start them inside mid-April and plant them out toward the end of May when I put most thing in the ground. I let them grow all summer. About mid July I see the sprouts stating to form, but they arent ready to harvest until late October/November. Keep the BT and Sluggo handy, the slugs and cabbage worms love them, and dont forget to stake them.