it's early in the season and I only have a few bloomed velvety dark red roses. I've noticed today that the edges of the petals are black. Temps have dropped down into the 40"s the last 2 days. Can this be cause for the black edges?
Extension Specialist, Home Horticulture/4-H
Department of Crop Sciences firstname.lastname@example.org
Yes, cold temperatues will cause red roses to darken. Similar things happen with other plants and the pigments they contain in response to temperatures.