It may be cold outside, but no need to wait for April showers — you can already spot signs of greenery.

Urban forester Georgia Silvera Seamans and ecologist Marielle Anzelone host a Twitter event on Wednesday evenings where they invite people to post their photos of local wildflowers using #wildflowerhourNYC.

Silvera Seamans described her favorite this week, the Cornelian cherry. She said it's actually not a cherry but a dogwood, introduced from East Asia, most noticeable in the spring. "They have these small beautiful flowers that are quite a lovely yellow, like floral sunshine on gray days," she said. "The buds are swelling and opening right now."

If you want to submit a wildflower photo, do it! Snap a picture of what you see and tweet it to us @wnyc, or tweet it to #wildflowerhourNYC Wednesday nights between 8-9 pm.