Saffron is the Worlds most expensive spice, some varieties sell for as high as $1500 per lb . The only other herbs you can grow, that attain anywhere near that price are illegal.
True Saffron spice comes from the stigma of the Saffron corm flower [Saffron Crocus], yes that is c-o-r-m, not corn. The corm is the bulb from which the Saffron is grown - it is a rounded tuber that produces up to 3 flowers, although in its first year you generally only get one sometimes 2. The Saffron spice is derived from the flowers stigma.
Plant the Saffron crocus bulbs roughly 4 inches deep with 5 to 6 inches separation between bulbs. Saffron multiplies rapidly so don't be deceived into thinking the spacing is too far. In a relatively short time you will find yourself having to thin them out a tad. They will produce much smaller substandard flowers if crowded and should be divided every few years.
Late July or early August is the opportune time to plant the bulbs. The plants emerge as spring is knocking on the door but when there may still be some light frosts. In the early stage of their seasonal cycle there are no blooms.
Saffron Care and Cultivation
Once the bulbs are planted they are low maintenance. They survive in below zero temperatures, up to -15 Fahrenheit, and do just fine in the dog days of summer. When summer hits however and the heat bears down they go dormant. This is when they need you, be sure to water them, don't over do it just make sure they are kept moist, water sparingly. New leaves form again in early fall when cooler temperatures come. After the leaves comes the flowers.
Fertilizing is not needed unless your soil is abysmal, if you do decide to fertilize do so modestly . Fertilizer should be Potassium rich. Avoid Nitrogen based fertilizers which promote foliage at the flowers expense. Fertilizer should be spread near the plant base to seep through to the roots gradually, not more than once a year.
The plants attain a height of 4 to 6 inches. Blooms appear in Late summer through autumn and are generally harvested as pumpkin season approaches in October. In their first year they may appear late.
Hardiness Zones 6 to 9 are suitable for growing Saffron Crocus. In colder zones they can also be grown, but the bulbs should be dug up and stored indoors over winter. If you are going to do this allow them to experience a few of early winters first frosts. Once you dig them up they should be stored in sand or dry peat. They can also be planted in containers and transported in and outdoors on a seasonal basis.
In Hydroponic grow rooms the corms can be planted, flowered, and harvested in 45 to 60 day cycles. This is not feasible with soil based gardening as we need to rely on the seasons Mother Nature provides. See: Hydroponic Saffron
Harvest of Saffron Stigmas
Harvest To harvest, pick the flowers as they open. Inside the flower will be 3 , sometimes only 2 deep magenta colored stigmas which is what you want to harvest. It is dried and becomes Saffron Spice. Do not confuse other flower parts with the red gold that is the stigma - the rest of the flower is useless from a culinary point of view.
You will probably notice that the deep red strands / stigmas are very fragile - they would blow away with the slightest breeze and they frequently do. Electric dehydrators or even sun drying them does not do justice and frequently leads to disappointment. The best way to dry them is to allow the air to dry them naturally, remember now - a slight breeze and they're gone. I like to dry mine on a simple sheet of paper in a dry location away from any fans or open windows.