Well as a rule, most lupines are not adapted to summer heat and occur in alpine areas.

Thus, your success in SC seems doubtful to me, and starting seed this late in the year even more so, unless you plan on growing them in a climate controlled environment.

That said, I have never gardened in SC, and I could be wrong..but that's what I know from my area (Arkansas).

He lives in NC but lupines are not that easy in NC either as far as I can tell. I tried them from seed a couple of years ago. I don't remember well but I think all I did was soak them and they sprouted readily. I started them early in the year and grew them in pots and planted some in the garden in fall. Also left one or two in pots and left them out all winter. The next spring they put on more size and bloomed...I was delighted. They're beautiful. But they didn't enjoy the heat of summer and didn't hang around after that. So I may grow them again but not expect them to be perennials.

There are some other types of lupine which might tolerate more heat. I've seen plants of them at Annie's Annuals and also a variety of lupine seeds at Eden Brothers.

It may not have been clear that I'm in NC too.

My experience is with California wildflower type lupines, but perhaps it will help. It is very difficult to get them to absorb the water they need to swell and germinate. I tried soaking some for days and they didn’t swell at all. So I nick them using a toenail clipper while holding in my fingers. It just needs to be a tiny nick or scratch, just enough so that they can imbibe some water. Some people recommend sandpaper but I had more trouble trying to figure out how to do that.

@dbarron and @erasmus_gw, that's pretty disappointing :-(

Here, the rule of thumb was to never plant until May 1 because we always have a late frost. Then last year, we had a frost on May 15! So I'm only just now starting seedlings. Tonight is supposed to be 39, but it's supposed to stay over 50 starting Friday.

I have a fairly large part sun garden that I'm starting, and needed something spiky to balance out all of the irises and lilies. I use speedwell and tall phlox for this in other areas, but for this much space I really wanted something I could start from seed. Our summers can get over 100F, though, so as I'm reading about the temperature tolerance, I'm thinking this might not be such a great solution after all :-/

I already have them, though, so maybe I'll put them in a pot and just hope for the best. Thanks for the tips, @socalgal_gw Zone USDA 10b Sunset 24!

Hardy perennials are frost tolerant. Here, we starting planting them out about now.

I wonder if lupines would bloom if sown in August and overwintered in your climate. We can almost grow them. They are noticably happier a few miles north, and suffer a few miles south - and this is upstate NY.

Given how they self-seed, I wonder if you could grow phlox from seed. I've had some quite nice ones show up.

Winters have been pretty bad here for the last few years. This last winter dropped down to 3F! Growing up I rarely saw anything under 30. A lot of my plants died this winter.

I see that lupines can handle down to -30F, though! And their best temperature is 32-86F. Maybe I'll hang on to the seeds and start them in early March 2024. I think that I can probably grow them as an early-blooming annual, but we'll be over 86 before the end of May.

I have tall phlox in another garden, but I bought it as a young plant from a nursery. It spreads slowly, but if it drops seed then nothing grows from them.

I could probably get 3 "good" plants out of it right now (after 6 or 7 years). But I'm filling in an area that's about 5,000 square feet, so I needed more like 30 :-/

I'm about to run out of time for anything, though. I can't afford to buy 30 plants, so I might just divide up my phlox and speedwell and fill in where I can.

While knowing nothing about lupines (more or less, since they won't grow here), the best time to plant would probably be August. Many native annuals (which lupines are not) germinate in fall and grow over the winter, to flower in spring.
I was totally surprised this year watching my american basketflower seedlings, go through -7F and not even blink, and now they're headed for the sun (3 foot) and will be flowering in the next month.

Jason, I'd look up the wintersowing forum here. Seeds sown in containers outside sprout when they're ready. Less work than growing indoors under lights. I started mine in early spring indoors because I figured plants would be bigger going in to winter. It worked, but I thought they died out due to the heat of summer. If your temps are that hot , peren.all, they should be able to make it here. Maybe your soil is more favorable to them.

Jason, for me tall phlox is pesky. It comes up everywhere, especially right next to the crown of roses. If you really want some color why not sow seeds of annuals like zinnias? There is still plenty of time for them.

Lupinus arboreus, littoralis, podophyllus, polyphyllus, russel hybrids, sericeus, and texensis , Pour hot water over seeds, let soak 1-3 days until swelling noticeable. Sow at 20ºC (68ºF) for germination in more than two weeks.

Lupinus lepidus, perennis , Pour hot water over seeds, let soak 1-3 days until swelling noticeable. Sow at 20ºC (68ºF), if no germination in 3-4 wks, move to -4 to +4ºC (24-39ºF) for 12 wks, then return to 20ºC (68ºF) for germination.

I wouldn't recommend growing Lupinus polyphyllus in the eastern US. It's not native and it will cross pollinate with Lupinis perennis. The endangered Karner Blue Butterfly uses L. perennis as a host plant, but they don't use L. polyphyllus or perennis/polyphyllus hybrids. L. polyphyllus is invasive in Europe also.

Jason, don't bother with the refer until the seeds have absorbed some water. Cold dry storage is only storage, it does nothing to break dormancy.

I'd try the hot water over seeds, or it wouldn't hurt to lightly nick or even nail file a spot on the seed. Then I'd sow in pots and put them outdoors. Here in my cooler wet Z8 I'd have done it about 8 weeks ago. Temps dipping briefly to frost overnight wouldn't hurt them. In fact, fluctuating day/night temps just may be helpful.

And be patient. They could take anywhere between 2-4 weeks to germinate.

I wintersowed a couple different lupine last year in zone 6 and got quite a few to sprout and become seedlings. They were one of my favorite perennials to wintersow because the foliage is so unique in shape, and it was cool to observe it growing up from such a tiny sprout. I purchased seed from Swallowtail. It’s definitely a good option if you’re wanting a lot of lupine!