The leaves are turning yellow and there is damage everywhere in the plant. We had a light frost about 3 weeks ago. Is this frost damage? If so, do I trim the leaves that are damaged? Also, can anyone ID this plant. I think it is an Agave Difformis. Any help will be appreciated. Thanks,
The damage pictured looks very much like frost/freeze damage. The water in the leaves freezes and ruptures the cells leaving behind pitted, yellow patches that look like the leaf has been "crushed" flat. The areas will often turn yellow first then black or brown and dry up leaving an obvious dead patch. Here is some info on taking care of agaves with frost/freeze damage. the first link is from University of Florida and includes images of Agaves in their collection. This may help provide an ID for your plant.