Nitrogen, iron fertilizers can produce dark green leaves
Nitrogen causes stem growth as well as dark green leaf color. Adding only an iron fertilizer or chelate causes the new growth to become green but does not stimulate new growth that much.
Tomas Kauer - Las Vegas Syndicated News 
Nitrogen causes stem growth as well as dark green leaf color. Adding only an iron fertilizer or chelate causes the new growth to become green but does not stimulate new growth that much.
