Seed spices are generally the easiest spices to grow. Learn how to grow sesame seeds at home, with guidance for growing mustard seed and growing cumin.
Seeds used as spices to flavor foods played a prominent role in the origins of agriculture. Some have been used for over eight millennia, and the flavors we savor today are much like what pre-pottery Neolithic people used to add interest to their meals. Mustard and cumin made frequent appearances in ancient diets, and sesame was among the earliest oil crops.
When you plant these spice seeds, you hold the evolutionary history of thousands of years of collaboration between humans and nature — and also your own culinary future — in your hands.
Growing Seed Spices
You’ll have the best success growing spice seeds from a respected seed saver working in your region or in a climate similar to yours. (Planting seeds from your spice rack will not give good results.) A key difference between growing spices and herbs is the time to harvest. Whereas herbs grown for their leaves can be ready to harvest in mere weeks, spice plants used for their seeds can take four months or longer to reach harvest.
While you can grow seed spices indoors, yields are typically low. Annual seed spices grow best in spring and early summer. Unless you have moderate winters, fall planting isn’t ideal because of decreasing daylight hours and smaller pollinator populations. For biennial or perennial spices, late-summer planting works as long as plant root systems have time to mature before cold weather sets in.
Harvesting and Storing Homegrown Spices
Harvesting spice seeds requires a few special steps. You’ll cut off the seed heads or seedpods and dry them inside a bag or on screened herb-drying racks. For large harvests, use what I call the “candy-wrapper” method, laying out a piece of air-permeable fabric on dry ground, placing the seed heads or seedpods in the center, and rolling the fabric ends like a candy wrapper. Hang the fabric roll in a protected location with good air circulation until dry.
Seeds that don’t easily separate from their plant parts require threshing. To do this for small quantities, put the harvested parts in a pillowcase and beat it on hard ground or with a stick.
Newly harvested spices will smell stronger after they rest in an airtight container for a few weeks. When stored in airtight containers and away from direct light, your spices will last three years or longer. For peak quality, package spices in portions you’ll use in about three months. That way, you won’t expose years’ worth of spice to the air when you need a small quantity for cooking or medicine.
Growing Mustard Seed
Mustard seed is the second-most-consumed spice on the planet, behind black peppercorn. Canada and Nepal are the world’s top mustard producers, but it’s so easy to grow, you don’t need to rely on imports. Plant a handful of seeds into prepared soil in early spring, and mustard practically grows itself! You have three distinct mustard varieties to try.
Leaf mustard, Brassica juncea, is commonly grown by home gardeners. Also known as “brown mustard,” these plants produce large quantities of tasty brown seeds that easily substitute for other varieties. They work particularly well for a whole-ground mustard, having a tangy flavor similar to horseradish. Plant extra, and harvest the young, frilly leaves as salad greens.
White and yellow mustards are variations of the variety used as a condiment on hot dogs. Actually of the same species, Sinapis alba, white or yellow mustard is mainly grown as a field crop or even a cover crop. The entire plant is edible, but you’ll enjoy blending the seeds to make the mostly smooth, vibrantly colored condiment at home.
The seeds of black mustard, Brassica nigra, have a hard outer coating that pops like popcorn when roasted. If you like to cook South Asian cuisine, you’ll appreciate the strong nutty flavor they lend to many of the region’s dishes. In stores, you’ll find black mustard oil. At home, try infusing a mild oil with your roasted seeds.
Check out this video on how to pickle mustard seeds!
Growing
Mustard can develop a 3-foot-long taproot. Grow this spice in prepared ground, in deep raised beds, or in deep containers. Plant seeds in early spring, 1/4 inch deep in full sun to partial shade. Seeds will germinate within 2 to 5 days. Mustard prefers cool temperatures, and seeds do best between 50 and 75 degrees Fahrenheit. Mature plants will tolerate up to 85 degrees but become susceptible to pests in higher heat. The plant does well in a wide range of soil types. In compost-rich soil, mustard can tolerate pH ranges from 5.0 to 8.0. Before planting, add 3 inches of compost and incorporate a slow-release nitrogen fertilizer, such as feather meal or soybean meal, into the soil.
Mustard plants are self-pollinating and make a lot of seeds, so the pods grow heavy. Stake the slumping portions of the plant upright or space plants far enough apart — 8 to 10 inches of space — to allow room for mustard’s natural arching habit when seeding. The profusion of seedpods in various states of drying is even more beautiful than mustard flowers. Colors range from green to pink, purple, yellow, and brown.
I recommend over-seeding when growing mustard seed and eating the extra seedlings as baby greens when they’re 2 inches tall. Continue to harvest the leaves on remaining plants between 20 and 40 days, and your seed harvest can begin after about 100 days. If you allow the plants to bolt and flower, they can grow up to 5 feet tall.
Harvesting
Harvest mustard before the oldest pods feel papery, cutting the seed tops just above the last leaves (if you miss your chance, you could end up with endlessly self-sowing mustard). Place the tops in a paper bag or use the candy-wrapper method to finish drying them. Thresh and remove the chaff.
You can plan on getting 3 to 5 tablespoons of seeds from each plant.
Medicinal Use
You might not have known that mustard’s potent volatile oils have a medicinal use. When used in powdered mustard seed packs or plasters, these oils create a rubefacient effect on the skin, drawing blood to the area on which the mustard is applied. This circulatory system stimulation can soothe sore muscles, reduce joint inflammation, and decrease pain. Use caution, as mustard can cause irritation when applied topically.
How to Grow Sesame Seeds
Sesame, Sesamum indicum, is often called a survival plant. Its fat and protein content, along with its utility as an oil, paste, and flour meal, have helped subsistence farmers since antiquity survive in harsh climates. Sesame is also itself a survivor, tolerating extreme heat, crowding, and poor soil. Landraces have adapted to monsoon and drought conditions. The plant’s natural dehiscence — or shattering of the seedpods — also helps ensure sesame’s self-propagation. As a result, wild and naturalized sesame can be found in many warm regions of the world.
Despite 5,000 years of cultivation, probably beginning in India, industrial sesame production only became possible in the mid-1900s. A natural genetic mutation made some seedpods indehiscent (non-shattering). This allowed growers to breed pods that were easier to harvest mechanically. Still, harvesting sesame has remained a largely manual undertaking worldwide.
Dried sesame lacks the aromatic, volatile oils associated with some other spices. An antioxidant called sesamol prevents its oils from volatilizing, so sesame is even used in margarine and ghee to make them shelf-stable. Yet, when you roast or toast the seeds, all that oil volatility activates, revealing sesame’s oily, nutty flavor well-suited for using in savory dishes, breads, candy, pastries, and desserts, and for blending into tahini. In other words, cooking causes the flavor to…open sesame. (You had to see that one coming!)
Growing Sesame
Sesame is an easy-to-grow spice that produces mature seeds in about 3 to 4 months. Store-bought sesame seeds are typically all white, because they’re hulled and sorted for color purity, but home gardeners will find a range of colors to try. The black seeds, prized by gastronomes, have edible hulls.
The plants and flowers are quite beautiful, with bell-shaped flowers growing up to 6 feet tall that open for weeks, making them work well in pollinator and bird gardens. The plants also benefit the soil by reducing the number of harmful nematodes and fungal pathogens, and their pervasive root structure breaks up compacted soil.
Sesame is a warm-weather crop. It requires temperatures above 70 degrees for good growth, and mature plants can tolerate up to 105 degrees. For an early start, plant seeds indoors 6 to 8 weeks before ideal outdoor conditions, using an electric seed mat to warm up the soil. Incorporate 3 or 4 inches of compost into your soil before you start planting. Add feather meal, bat guano, or other slow-release nitrogen sources for the best yields. Sow seeds ¼ inch deep, and water daily until plants begin to germinate, which will happen between two and five days. Use row covers and mulch to keep the soil warm.
Some sesame varieties tolerate wet conditions, while others only thrive in dry conditions. Some sesame grows in a narrow, non-branching fashion suited to rows. Others are branching and require more space. Some varieties need dense planting to produce; others need more space. (You see the trend: Get to know the varieties you choose.)
Harvesting
In consistently hot weather, seedpods are harvestable in about 90 days. Otherwise, plan on harvesting between 110 and 130 days. For small production, pick individual pods when they’re mostly dry, but let the plants continue to grow. Like okra, pods will keep forming at the top of a plant. Finish drying pods on a baking sheet or drying rack.
For larger harvests, when 75% of the lower pods show signs of drying, cut the tops. Hang-dry the heads in a paper bag or dry on a tarp to minimize losses. Thresh and winnow the chaff. You can expect 1 to 3 tablespoons of seeds per plant.
Medicinal Use
The seeds of sesame provide a rich medicine. The oil, abundant in lignans and tocopherols, demonstrates prolific antioxidant activity. Consuming the seeds may reduce blood pressure from their beneficial lipid content, shown to decrease the narrowing of the arteries and oxidative damage. Sprinkle the seeds liberally on foods or eat more tahini for these favorable effects.
Growing Cumin
Beloved the world over for its musky, pungent aroma and peppery, nutty taste, cumin makes its way into a wide variety of foods, including curries, pickles, breads, and seasoned meats. Yet, Cuminum cyminum is difficult to produce commercially. Native to the Eastern Mediterranean and Egypt, most of the world’s supply is grown today on small farms in India and China. In India, cumin is such a critical staple food and so little is grown that the government mandates local demand be met before any cumin is allowed to be exported.
Growing cumin is tricky unless you have the perfect climate. It requires a long, warm — but not hot — growing season. Plants are prone to stunting, and cumin’s top-heavy foliage sits on spindly stems, subject to being knocked over by wind or rain. On the upside, mature cumin is drought-tolerant. Plus, its compact size makes it good to grow in pots you can temporarily move indoors during inclement weather.
Between the complexity of growing cumin and extreme weather events, the surplus for international sales is small. Cumin scarcity is a real risk in the future. Supply your own demand, and expand your gardening skills by mastering the art of growing this spice at home.
Growing
Sow seeds indoors, in ideal conditions, 4 to 6 weeks before last frost. To improve germination, soak seeds for eight hours. Then, sow seeds on the surface of 65-degree soil. Water deeply to settle the seeds. Mist the soil with a spray bottle or misting hose twice daily until germination. From then on, you can water regularly, but because contact with wet soil increases fungal risks, water only when the top 1 or 2 inches of soil feel dry.
Take plants outdoors when temperatures are between 50 and 80 degrees — their temperature sweet spot — and the weather is mild. If growing in containers, use individual 6-inch pots, or grow a few plants together in larger pots. To grow larger quantities of cumin, outdoor garden beds under the protection of low polytunnels are best. In humid areas, give plants 6 or more inches of space to limit fungal risks. In dry areas, plant only 3 inches apart on 6-inch rows to help crowd out any weeds. Temporary shade helps control temperatures on hot days, while plastic covering can protect plants in cooler or wet weather. Aim to keep plants in their sweet spot throughout their life cycle.
Weed early and as often as you can. Young cumin plants have fine, upright, feathery foliage that can easily be outpaced by fast-growing weeds until the plants are nearly mature and have a significant leaf mass.
When plants bloom, leave them outdoors in a wind-protected location, near other flowers to encourage insect pollination. Grow at least three plants together for cross-pollination (hand-pollination is ineffective).
Harvesting
Remove seed heads when the plants begin to wither. Dry them under cover. Thresh dried heads and winnow the chaff. Plants produce about 1/4 to 1 teaspoon of seeds each.
Medicinal Use
Cumin’s earthy, aromatic seed can be used medicinally to regulate insulin levels for those experiencing insulin resistance or Type 2 diabetes. A 2016 study in the Iranian Red Crescent Medical Journal showed that consuming cumin seed for eight weeks not only lowered insulin levels, but also resulted in lowered cholesterol and weight loss. For those seeking these results, you’ll need more than a sprinkle in your weekly curry; take larger doses of encapsulated cumin seed.
Tasha Greer is a homesteader and writer in North Carolina. Connect with Tasha at Simple Stead.
