Most gardeners think of crocuses as harbingers of spring, but the corm that produces saffron, one of the most expensive spices in the world, is a beautiful autumn bloomer. Growing saffron crocus (Crocus sativus) at home may just be a surprisingly low-maintenance, highly rewarding addition to your late-season garden — and to your kitchen!
Grown and harvested since antiquity in many places around the world, including Egypt, Greece, and Rome, saffron has been used in cosmetics, as dyestuff, for medicine, and in cooking. The brilliant red stigmas lend a strong yellow color to food or textiles, and during the Middle Ages, a paste colored with saffron was even used by monks as a substitute for gold in the production of illuminated manuscripts. Saffron is still expensive in this age of labor-saving machinery because it must be harvested by hand — and, as each plant typically produces 2 to 4 flowers, with only three stigmas each, it takes a vast number of plants (as well as time and labor) to produce a mere tablespoon or two of spice. Be cautious when ordering saffron crocus corms: don’t confuse C. sativus with autumn crocus, Colchicum autumnale, as the latter is poisonous. Only C. sativus produces harvestable saffron — no other crocus species does, whether it’s spring- or autumn-blooming.
Saffron crocus is commercially farmed in Iran, Greece, Spain, Morocco, and India, among other countries, and the plant is often overlooked as a warm climate “exotic,” but it’s cold-hardy to Zone 6. Some growers in cooler climates have protected the plants under fabric row covers or lifted and stored the corms over winter, but these are not optimal choices. Growing saffron crocus in containers may also be possible, but in some climates, successful overwintering may still necessitate lifting and storing the corms, or burying the containers in the ground.
Plant saffron crocus in late summer or early autumn — mid- to late August or early September is best in most climates. Site them in full or partial sun, in well-drained soil. Heavy clay may restrict growth, and the plants may not bloom. A sandy loam is ideal. Apply an amendment of compost before planting, and side-dress with compost annually, either in spring or fall.
Saffron crocus won’t perform well in boggy soil, and it doesn’t tolerate prolonged periods of rainfall. Flowering will be affected by overwatering, and the corms may rot. If your climate tends to be rainy, this may not be the plant for you.
Position plants at the front of the bed, both for ease of harvesting and because they’re small, only 6 to 12 inches tall. You’ll want the six-petaled, cup-shaped blue-purple flowers to make a statement for their brief blooming period. Saffron crocus can be tucked into raised beds or planters, and they make excellent additions to rockeries, dry riverbeds, and xeriscape designs. The thin, grass-like leaves first appear in spring, and then yellow and dry during dormancy in the hottest part of summer, only to return with cooler autumn weather and the flowering period. They may re-emerge just before or just after the flowers, but typically the leaves and flowers appear at nearly the same time. Don’t cut back the leaves after the flowers are finished; allow them to fade on their own.
Plant corms, pointed ends up, at a depth of 2 to 3 inches. Group the corms together for more visual impact in the garden, spacing them about 3 inches apart.
Saffron crocus may bloom in its first year, about 6 to 8 weeks after planting, but don’t be alarmed if flowers don’t appear until the following autumn. Peak blooming occurs when the plants are 3 to 5 years old. The flowers will open during the day and close at night. They’ll often stay closed in wet weather or under heavy cloud cover. After the flowers have faded, the corms will begin to form secondary corms underground.
Recognizing the part of the plant to harvest is easy: Just look for the inch-long, bright-red stigmas, sometimes called “threads,” which are encircled by yellow stamens in the center of each flower. Use a pair of tweezers to carefully remove them. Harvest on a dry, sunny day, when the stigmas are still fresh (not dried). You can use the stigmas in cooking right away, or, if you want to save them for later, lay them on a sheet of baking parchment and dry them in a sunny, undisturbed location. They’re very small and light, so it’ll only take a day or two for them to fully dry. Store dried saffron wrapped in foil or paper in a glass or plastic container to protect them from degradation through exposure to light.
Saffron crocus corms live only about 10 to 15 years. This species of crocus is triploid: The cells have three sets of chromosomes per nucleus, which renders them sterile and thus impossible to propagate by seed. You won’t find these crocuses growing in the wild! Saffron crocus must be propagated vegetatively — fortunately, it’s easy to do. If you dig up a mature corm, you’ll notice tiny secondary corms at the base. These may be removed and replanted. Divide plants when they’re dormant, usually at the end of July or August. Plants should be divided every 3 to 4 years to prevent overcrowding and promote flowering.
Like the other members of its genus, saffron crocus is relatively pest- and disease-free. Rodents, such as squirrels and mice, may chew on or remove corms from the ground, and will usually attack right after planting. Try interplanting crocus with toxic bulbs, such as miniature Narcissus, to reduce the risk of losing your valuable corms. You could also tack pieces of bird netting over the corms using landscape pins.
Use saffron threads very sparingly in recipes — a little goes a long way! Saffron will add a complex, slightly sweet, almost grassy flavor to dishes, and can easily tip over to the pungent side if overused. Most cooks will know it as the crowning ingredient in Spanish paella, but it’s also frequently used in risottos, fish dishes, curries, and puddings.
You might expect the most expensive spice to have equally expensive corms. Happily, that’s not the case. Saffron corms can range from 50 cents to $1 each, depending on the vendor. With such low starting costs, why not grow commercially?
Saffron’s retail price by weight is impressive, at up to $10,000 per pound. When you consider that each flower yields just three little threads, tweezed out by hand and then dried to 20 percent of their fresh weight, you’ll start to get an idea of the sheer volume required. A pound of saffron is nearly a gallon by volume, and it takes 70,000 flowers to produce that quantity — a football-field-sized patch of plants. Don’t forget, harvest season lasts only 2 to 3 weeks, and the threads have to be hand-picked. No doubt, your back would ache before you reached the 10-yard line.
There’s a big difference between growing saffron commercially and only supplying your family and friends. While your starter bed might only yield a tablespoon of spice the first year, the plants will multiply, and the number of flowers will increase accordingly. Plus, you can glean the flowers from their bed in 15 minutes or so each morning. Figure out how much saffron you use in a year, and start small. Picking flowers can get tiresome after a while. Then again, you can always let the excess flowers bloom if you’d like; it won’t end the harvest like forgetting to pick green beans or peas would. — Andrew Weidman
Ready to try cooking with saffron? These recipes will help you get started!
Sheryl Normandeau is a freelance writer and homesteader from Calgary, Alberta. You can follow her gardening and outdoor adventures on her blog, Flowery Prose.
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