Everywhere I have seen offers Crocosmia bulbs in the spring, though Digging Dog Nursery still has them listed, so you could contact them to ask if they are currently shipping. http://www.diggingdog.com/

I have gotten them in the past from Brent and Becky's Bulbs in the spring, and they had a number of varieties with differing shades of red, orange and yellow.

In my experience, if a plant is only offered in one season, it is because the plant is most likely to grow successfully then. Since most Crocosmia bloom late summer (Lucifer seems to be an exception) It may be because the plant needs the long season of growth to get good roots so that it will grow and bloom well. It might be that it doesn't use light to determine when to grow, and that since soil is warm in the fall it is too likely to try to grow leaves, etc and use up the stored food in the bulb so that it can't grow the following spring. I'm not sure, but just be aware that you may not be as successful planting now as you would be waiting until spring.

It applies to all the plants which are borderline hardy that they should be planted in the spring, so they establish better root system before the winter.

I agree. I don't think you could find this plant in the fall and if you could I wouldn't buy it. Crocosmia is borderline for my zone so spring is the best time to plant it. It is suggested to mulch them before winter, but once they are established, I find this isn't necessary. If you do plant them now, give them a good top layer of mulch to protect them from the cold. But personally I'd wait until spring. You're not going to lose a growing season but you might lose your money.

Like others mentioned, I agree that it is better planted in the spring.

About mulching, the "protect from cold" idea is not really true. Mulching helps to keep the soil evenly frozen, preventing freeze/thaw cycles that can cause excess moisture to form in the top layer of soil which can rot plants. With mulch the soil stays a constant, evenly cold temperature so you don't get wild swings where the soil melts and then refreezes.

But back to Crocosmia, many of the colors other than red are less cold hardy to begin with, and I'm not even sure how well they do in zone 6 so I'd certainly wait until spring on anything but Lucifer.

The Lily Garden also has a few and they are listed in their fall catalog.

Well, as far as cold hardiness goes, I'm not sure about the color thing. In the past, I always dug and stored my Crocosmia overwinter. A few years ago, I got tired of that and just left them in the ground thinking they wouldn't make it. They did make it and have been coming back each year. None of mine were red, they were all the yellow varieties. Babylon was one of them. I don't mulch for winter and my zone is technically zone 4, but IMO at least has been behaving more like zone 5 for a good number of years.

Kevin

Thanks Kevin for suggesting another hardier-than-usual Crocosmia (besides Lucifer, that is). I have tried half a dozen varieties over the years, but the only one that has survived for me more than 2 yr. is Lucifer. I think I will try Babylon, just to have another colour to go with my Lucifer.