How to grow Quinoa
Updated October 2026
Quinoa is a seed crop related to spinach, beets and the weed lambsquarters. It grows best where summers are cool, because heat during flowering, above roughly 90°F to 95°F, leaves the pollen sterile and the heads empty. In the US it suits the Pacific Northwest, the northern tier, high valleys of the Mountain West and coastal California, and it is grown in the cool season in the low desert.
📖 Our full guide: How to Grow Quinoa
Not to be confused with: Young quinoa looks very like lambsquarters, a common weed in the same family, so mark your rows when you sow.
Where to plant
Grow quinoa in full sun in well-drained soil with a near-neutral pH. It tolerates poor soil and drought well, but waterlogging causes stunting and damping off. The critical factor is temperature at flowering: WSU found that days above 95°F while plants were flowering caused complete crop failure in eastern Washington. Plan sowing so that flowering, about 40 to 80 days after sowing, falls in cool weather.
Quinoa has been grown successfully from sea level on Washington's Olympic Peninsula to 7,600 feet in Colorado's San Luis Valley, and in coastal central California and Oregon's Willamette Valley.
- Pacific Northwest, Northeast, Midwest, Northern Plains and Mountain West: sow in spring as soon as the soil can be worked, so plants flower before the summer heat.
- Desert Southwest and Southern California: sow in fall and winter, so the crop flowers and ripens in the cool season.
- Northern California: sow in the cool season or early spring, avoiding flowering in hot inland summers.
- Hawaii: cool-season sowings, best at higher elevations.
- Alaska: sow in late spring; long days and cool summers suit it.
- Florida, the Gulf South, Texas, the Mid-South, Mid-Atlantic and Southern Plains: not reliable, as hot, humid summers stop seed set.
Choosing a variety
Choose varieties suited to long days and cool summers, or day-neutral types. Store-bought quinoa is usually a short-day Andean variety that may not mature in the US. WSU trialed Black, Blanca, Cahuil, Cherry Vanilla, Colorado 407, Dave, Kaslaea, Linares, Red Head and Temuko, and found yields varied greatly between a hot, dry site and a cool maritime one. Seed companies in the Pacific Northwest offer varieties bred for maritime climates.
How to plant
- Test the soil if you can. Work in compost or a modest amount of nitrogen fertilizer, but keep fertilizer out of direct contact with the seed, which can stop germination.
- Sow seed about 1/4 to 1/2 inch deep into moist soil, in rows 8 to 24 inches apart, and cover lightly.
- Keep the surface from crusting until seedlings emerge; the small seeds dry out or fail to push through a crust easily.
- Thin seedlings to a few inches apart for many small heads, or up to 8 to 12 inches apart for larger plants.
- Weed carefully while plants are small, as young quinoa looks like lambsquarters.
Watering and feeding
Quinoa is drought tolerant, but moisture matters most during flowering and seed fill, about 40 to 80 days after sowing. In WSU trials, a weekly drip watering of about 0.6 inch raised yields nearly fivefold and let plants set seed in a hot year when unwatered plots failed.
Nitrogen improves yields, but too much in a container can stunt plants. If you dug in compost or manure before sowing, extra fertilizer may not be needed.
Harvesting
Quinoa is ready when most of the leaves have dropped, the seed heads have dried and the seeds are hard enough that a fingernail barely dents them. Cut the heads on a dry day and finish drying them indoors on a sheet.
Rub or beat the dry heads to free the seed, then winnow off the chaff in a breeze or in front of a fan. Store the dry seed in sealed jars.
Using it
Most varieties carry saponin, a bitter, soapy coating. Rinse the seed well in cold water, rubbing it between your hands, until the water no longer foams, then cook it like rice. The young leaves can be cooked like spinach.
Companion planting
Quinoa is usually grown in its own block or rows, like a grain. It mostly needs sun and freedom from weeds.
Good companions
- Bush Beans A low crop that can share the bed edge without shading the quinoa.
- Sweet Corn Another tall summer crop for the back of the garden, though it needs more water and warmth.
- Corn
- Beans
Pests and diseases
Downy mildew is the most damaging disease of quinoa in wet areas. Birds take ripening seed.
Pests to watch for
- Aphids Clusters of small soft insects on leaves and the developing seed heads.
- Birds Seed stripped from ripening heads; net plants as heads dry.
Diseases to watch for
- Downy mildew Irregular pink and yellow patches on leaves with gray fuzz, spreading in cool, rainy weather.
- Botrytis gray mold Gray fuzzy mold on heads and stems in wet weather.
- Damping off Seedlings collapse at soil level in waterlogged soil.
Common questions
Why did my quinoa flower but make no seed?
Heat is the usual cause. Temperatures above about 90°F to 95°F while quinoa is flowering make the pollen sterile, and the heads stay empty. Sow earlier, so it flowers in cool weather, or grow it in the cool season if you live in a hot area.
Can I plant quinoa from the grocery store?
It may sprout, but store-bought quinoa is usually a short-day Andean variety that may not mature in US conditions. Buy seed of a variety suited to long days and cool summers.
How do I remove the bitter taste from quinoa?
Most quinoa is coated with saponin, which tastes bitter and soapy. Rinse the seed in cold water, rubbing it between your hands, until the water stops foaming.
When do I harvest quinoa?
When most leaves have fallen, the heads are dry and the seeds are hard. Cut the heads on a dry day, dry them further indoors, then thresh and winnow.
Where in the US does quinoa grow best?
Where summers are cool while it flowers: the Pacific Northwest, the northern tier, high valleys such as Colorado's San Luis Valley, and coastal California. In the low desert, grow it through the cool season.
Can I eat quinoa leaves?
Yes. Quinoa is a relative of spinach and lambsquarters, and its young leaves can be cooked like greens.
Sources we checked: Washington State University Extension: Grains, growing quinoa in home gardens (FS258E); Agricultural Marketing Resource Center (Iowa State University): Quinoa.
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