In article , John
writes
Hi,
Often when I see hibiscus plants for sale is a nursery, their leaves are an
envious dark green, darker than those on plants growing outside and darker
than I can make them with a balanced fertilizer. What is it that people add
to these plants to cause the leaves to turn so dark?

I'm told that it's a side effect of a dwarfing agent used on the plants
to make them suitable for use as pot plants.
--
Stewart Robert Hinsley