We are buried in white here in the northeast and I am craving green (although happy to be warm indoors). So I looked back through my photos to see what green plants I could find on or near this date in years past. Here are two candidates from 2012 — a mild winter — both photographed at Brooklyn Botanic Garden on January 31.
Autumn fern (Dryopteris erythrosora) is one of my new go-to plants. I really love ferns, and my previous go-to semi-evergreen was Christmas fern (Polystichum acrostichoides), but when the really cold weather sets in, it tends to flatten out and look like wilted lettuce. It's not very cheery in bleak weather, which runs counter to the main reason we usually choose evergreen plants — to brighten otherwise brown landscapes. Autumn fern isn't native like Christmas fern but tends to hold its green longer and stay upright better.
I had always wanted to try dwarf mondo grass (Orthiopogon japanicus 'Nana'), but the one time I did, I'm afraid I didn't give it enough light and it has failed to fully fill in. The patch seen here is on a knoll in the Japanese garden at BBG and gets some direct sun. Growing a solid mass like this probably takes a fair amount of time and cash, but it seems like a good low-maintenance alternative to turf — although it's probably best to minimize foot traffic.