Years ago a gardening friend of mine planted Lycoris radiata in her garden (NE Ohio) and the bulbs do try to grow during the fall and winter but the foliage was always knocked back by the cold. They would produce leaves in the spring, go summer dormant and out of a dozen bulbs a couple would produce flowers in the late summer.

I would think if the bulbs are planted in a southern exposure near the foundation of a building in really well drained soil they would do their best in zone 6, mulching them would help, but remember a winter mulch doesn't keep plants 'warm' it keeps the ground temp more constant. Once the ground freezes mulch will help keep it frozen, preventing heaving and temperature extremes.

When your Lycoris start growing in the spring keep them well fed and have them in a spot that does not get any additional watering during the growing season. They need to dry out after the leaves have died back in the early summer to ripen the bulbs in order to produce flowers.

Hope this helps, good luck!

What do you mean "planted at ground level?" The bulbs should probably be planted at least 4 to 6 inches deep and then put a couple of inches of mulch over them. If too shallow the winter might take them out with freeze/thaw cycle. Lycoris are planted shallowly when growing in pots.

I planted mine in early September and the leaves came up two or so weeks ago. I guess we are going to find out together what happens in zone 6. This is what they looked like a couple days ago.

I plan on covering them lightly but not too much, so they can still photosynthesize during the winter. If they make it nice, if they don't...

I read that...

"standard Lycoris culture requires that bulb necks be above ground level for floral bud development in the bulb, so burying the bulbs below ground level will discourage flowering."

"you should plant so that the neck is at soil level, or slightly protruding from the soil.

Bulbs of this kind that are buried beneath the soil will not flower as well. The only exception to this is if you are concerned that the plants won’t be hardy enough to survive in your region. Gardeners who are on the borderline of these plant's hardiness zones can bury the bulb just under the surface of the soil, as this will give it some extra protection against low temperatures and prevent the bulb itself from freezing."

Some seem to say that you can plant it a little deeper, but still not very deep. I suppose one needs to find the "sweet spot" in depth where they survive but may still flower.

And even here in z7, it has a problem with getting frosted back on the foliage. I've planted 3 or 4 years and still waiting for a bloom. I also had them planted in NE Oklahoma when I lived there, and it was about 50/50 whether you would get blooms for a given year. It would probably be best to stick with spring foliage lycoris in z6 and below (and maybe z7 too).