Good quality saffron has a deep red color and the threads are usually between 1.2 to 3.8 inches long.
Besides synthetic dyes, saffron can also be adulterated by addition of natural colorants from other plant tissues.
Saffron plant fare poorly in shady conditions. Saffron plant grow best in full sunlight.
A cool temperate climate is essential for saffron production. The natural climate for the saffron crocus is a Mediterranean climate.