Here's a response from another Jim.
My impression is that Lycoris do better in areas where the foliage gets
plenty of sun.
I suspect that many of the reports of Lycoris thriving in the shade are
based on observations made during their blooming period, when deciduous
woody plants are in full leaf and herbaceous growth in general is still
burgeoning.
Those same sites will generally be found to be very sunny during the winter
when Lycoris foliage is active. Those such as Lycoris radiata which produce
foliage in the late summer or early autumn need all the sun they can get in
our climate. Those such as Lycoris squamigera which begin to produce foliage
in late winter likewise respond well to strong sun exposure.
The most floriferous planting of Lycoris squamigera I have ever seen was in
full blazing sun: a field where seemingly thousands bloomed from a planting
naturalized long ago.
On the other hand, I also know from personal experience that Lycoris
squamigera will give light, erratic bloom in areas where it is shaded
throughout the year.
A week or two ago while visiting in western Virginia Lycoris squamigera was
to be seen in bloom in every small town, typically by the front porch,
around mail boxes, in curbside plantings or even marking abandoned
foundations. All of these were getting plenty of sun.
Jim McKenney
Montgomery County, Maryland, USA, USDA zone 7, where Lycoris squamigera
grows like a weed.