Yes, you can grow saffron--the most prized of spices--in your garden. In fact, if you spot a few purple crocuses blooming now among the last of the fall flowers, they may be Crocus sativa, or saffron.
But restrain your enthusiasm, please. Each blossom yields only three stigma (known as saffron threads). It takes 13,000-14,000 threads to make an ounce (worth about $70), and the process of picking, sorting, and storing the spice is long and laborious. Growing your own saffron is definitely not a get-rich-quick scheme.
But it's fun, and as easy as growing other flowers from bulbs. To get saffron flowers in October, plant the corms, or bulbs, between June and September. (Buy from a nursery you trust, and be sure you get the true Crocus, not Colchicum, sometimes sold as "Autumn crocus." These have six stigma, not three.) Start with a few and divide and replant after they have bloomed. The corms thrive in a hot, dry summer, and do best in a well-drained, friable soil that isn't too rich. If the ground freezes in your area, you might want to dig your corms, overwinter in a dry, cool place, and replant the following summer.
Twenty-five bulbs can produce about half a tablespoon of saffron threads the first year, more thereafter. You can cook with the fresh saffron threads immediately, or you can dry and store them. Dry on paper towels in a warm place for several days, then place in an airtight container. You'll find some helpful how-to-use tips here.
Don't want to grow it? You can buy saffron in the spice section of your grocery. (Here is a good photo of what you're looking for.) And here is my favorite never-any-leftover paella recipe:
1/2 cup chopped onions
2 garlic cloves, minced
1 cup long-grain white rice
1 7-ounce jar roasted diced pimentos with juice
1/2 teaspoon crushed saffron threads
8 oz. bottled clam juice
3/4 cup chicken stock or canned low-salt chicken broth
1/4 pound cleaned squid, bodies cut into 1/2-inch rings
18 large uncooked shrimp, peeled, deveined
6 mussels, debearded and scrubbed
3/4 cup frozen green peas, thawed
Preheat oven to 450°F. Heat olive oil in heavy large pot. Add chopped bacon and cook about 6 minutes. Drain bacon on paper towels. Sprinkle chicken pieces with salt and pepper. Add chicken to bacon drippings in pot and cook over medium heat until brown, about 7 minutes per side. Take out the chicken and set aside. Add onions, celery, and garlic to pot and saute until it begins to brown, 8-10 minutes. Stir in rice, pimentos, and saffron. Add clam juice and chicken stock to pot and bring mixture to simmer. Remove from heat.
Pour rice mixture into baking dish. Arrange chicken, shrimp, squid, clams and mussels (in their shells) on top. Sprinkle with chopped bacon and peas. Cover and bake about 45 minutes, until rice is tender, chicken is cooked through, and clams and mussels have opened. (Discard any that don't open.) Serve with lemon wedges to 6 ravenous diners.