I would not mulch heavily. Maybe with something that will stay fluffy, not pack down. I am lucky with Oak leaves, they stay crispy even when snow packed and wet. Shredded they stay stiff, allowing air and new leaves to push them aside in Spring.

I have 3 Oriental Poppies, two which have new leaves. I don't want to cover them heavily, like with a wood mulch. Wood keeps the crown wet, allowing rot over the long winter. Fluffy leaves seem to work well, protect but not packed to hold water on that crown. I want mine protected from our steady winter wind, cold doesn't seem to bother the poppies. Wind here dries everyone out, so the fluffy cover works well.

I know other leaves will soften up and then mat down over long winter. They smother stuff underneath, so not great for mulch. Maybe you could get some crispy Oak leaves from another person locally. Steal some bagged leaves along the streetside!! Good luck.

Thanks, I don't have oak leaves, but maybe if I go a'scavenging ;-)

Marianne