Oats (Avena sativa)

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Oats (Avena sativa)

Common Names 

Common Oat, Cat Grass, Wild Oat, Cat Plant, 

About This Plant

You may think you know about Oats, but how much do you actually know about Oats?

Beloved Oats, members of the Poaceae/Grass family, are annuals that grow in USDA Zones 3-9. They are easy to grow and their tufted, hollow, leafy, light-green culms, largely hidden by sheaths, reach about two to three feet in height. Oats are some of the most nutrient-dense and mineral-rich grains available and in addition to being a well-known, healthy, breakfast food and baking staple, offer amazing medicines in the form of their immature milky seed heads and in their stalks.  


Oats need full sun and will adapt to moist or dry, fertile or barren soil conditions. Oats are best grown in temperate regions. They sprout and grow quickly during the cool moist weather of Spring, or if in cooler areas, during the Summer months. Getting an early start and sowing Oats as soon as the soil can be worked is important because Oats will go dormant in the Summer heat. They have a lower Summer heat requirement and greater tolerance to rain than other cereals such as Wheat, Rye, or Barley, making them important in areas with cool, wet summers such as Northeastern Europe and even Iceland. Oats are cold-tolerant and are unaffected by late frosts or snow. Russia is the biggest Oat producer in the World claiming 20% of the 23 million tonnes grown annually worldwide. Canada comes in second with 15% of the world’s Oat production. In warmer climes, Oats are sown in late summer and early Fall. While often cultivated, Oats can also be seen naturalized in areas such as cropland, abandoned fields, and roadsides. Often they are planted along roads for erosion control. Though Oats can naturalize to areas, they rarely persist for more than a few generations. 


Flowers bloom on Oats from late Spring to Mid-summer and last one to two weeks. Flowers are green and inconspicuous panicles that form spikelets. The florets are either cross-pollinated by the wind or self-fertile. The florets develop into ripened grains later in the Summer or Fall. The grains are narrowly ellipsoid and narrowly furrowed along one side. These seed heads form a loose panicle atop the stem. The foliage of Oats is a characteristic bluish-green that once familiarized with is easy to spot from a distance in farmers’ fields. 


There are various insects that like to feed on Oats. The Canada Goose does too and consumes both the foliage and seedheads. Oats are used as feed for domesticated farm animals, especially horses either as whole or rolled Oats or as part of a blended food pellet. Cattle eat Oats as well, either whole or ground into a coarse flour. Oats can be ground using a roller mill, burr mill, or hammer mill. Oat protein is nearly equivalent in quality to soy protein. One hundred grams (3 ½ ounces) of Oats containing more than 34% of the recommended daily value (DV) of protein, 44% DV of fiber, several B vitamins, and numerous dietary minerals, especially manganese (233% DV), 66% DV of thiamine, 50% DV of magnesium, 75% DV of phosphorus, and 42% DV of zine, among others.  Europeans especially have a long tradition of using Oats as a nourishing food for those who are debilitated, weak, or healing from a long illness. 


Oatstraw is prized by cattle and horse producers as bedding due to its soft, relatively dust-free, and absorbent nature. Versatile Oatstraw can also be tied into a muslin bag and used to soften bath water. Oats are fairly ornamental in appearance, but nonetheless are rarely grown for ornamental purposes as its annual life cycle makes it more difficult to maintain in a garden than a perennial grass with ornamental properties. Oats are bio-accumulators of Calcium and other minerals, and simultaneously feed and “sweeten” the soil, meaning they increase soil pH. Humans have focused so much on oat grains as a food source, that only a small percentage of the population is aware of the exceptional medicinal uses of the Oat plant as a deeply nourishing and replenishing medicine for the nervous system as well as the integumentary system. Herbalists use Oats to calm frayed nerves and soothe debilitated conditions. 


Common Oats are also known as “Cat Grass” because Cats love to eat them.  Oats contain many nutrients that are missing from the animals’ diet. Many people grow this plant in containers indoors, especially for their house cats.


Oats are considered safe for all people–adults, elders, and children alike. The only caution for Oats is for people with gluten issues. Avenins present in Oats (proteins similar to gliadin from Wheat) can trigger celiac disease in a small portion of people. 


“…Avena’s dwelling places, which ar the wide open spaces

Where the wind and oatgrass make spine tingling music that

Call snakes out onto rocks to listen and fills the air with the 

Earth’s own sighs of pleasure.” – Judith Berger (Berger, 1998, p. 63)


Oats should be directly sown outdoors in early Spring. They are cold-tolerant and are unaffected by late frosts or snow. An early start is crucial to good yields as Oats go dormant in the summer heat. In warmer areas, Oats are sown in late summer or early Fall. 


Rake the soil to loosen and broadcast the oat seeds by hand–thick enough to suppress weed germination, but not too thickly, as it can lead to problems with lodging and may reduce yields. Cover seed with about an inch of soil to keep the birds from eating it. Water regularly, especially during the growing stage, and in about one to three weeks you should have germination. 


Winter Oats may be grown as an off-season groundcover and either plowed under in the Spring as a green fertilizer or harvested in early Summer.  


Oats should be directly sown at their final placement spacing and not transplanted. 


Oats require full sunlight and do not tolerate shade. They need good drainage and are drought tolerant but perform best if watered regularly. Oats will grow in poor to average soils. Dressing the seed bed with compost will increase vitality. They like regular watering, especially during their growing stage. Oats can be grown as part of a grouping or as a container plant. Seeds are fully mature in 45-60 days depending on weather conditions.


The milk stage happens during a narrow window and if you are desiring to harvest “Milky Oats” you’ll want to visit your Oats daily so as to not miss it. Once the seed heads appear and become plump, squeeze the tops daily. The green, immature milky Oats are ready to harvest when they exude a milky sap when pressed firmly between the fingers. Harvesting the tops is easy and fun, just pinch the stem between two fingers, slide your hand up the stem and the grains will pop off one at a time. The Milky Oat tops should be tinctured immediately in alcohol or dried thoroughly in bunches before storing either whole or after cutting into small pieces. 


Oatstraw can be harvested after the immature Oat tops are collected by cutting the stem close to the ground. Oatstraw should be cut into half-inch segments and dried thoroughly for teas and infusions. Oatstraw can be harvested and dried at any stage of plant growth. 


Oats are mature when the stalk and seeds are good and dry. When harvesting mature seed by hand, this is most efficiently done by threshing a handful of oat stalks back and forth into a large container such as an immaculately clean garbage can. The dropped seeds can then be cured until the chaff is dried. The chaff can then be removed by winnowing. To winnow, the seeds and chaff are vigorously rubbed or stomped upon, then slowly dropped in front of a fan or within a light breeze to blow away the lighter chaff and retain the seed. 

Seed Harvest

Seed collection is very easy. Wait for the seed clusters to turn brown and strip them from the plant.  Allow them to dry on a plate for a few days and either crumble or pick apart the seed heads to separate the seeds. Allow the separated seeds to dry a few more days before packing them away in a cool, dry, airtight container. 

Plant Uses

  • Food Source
  • As a decorative grass
  • Makes a very attractive plant to use in flower arrangements
  • Erosion control 
  • Animal feed
  • Culinary Creations
  • Medicinal purposes as Milky Oats or Oat Straw, internal and external

Culinary Uses

For a grass species, the seeds of Oats have a relatively high protein content.  They are chiefly eaten as porridge but are also used in a variety of baked goods, such as oatcakes, oatmeal cookies, and oat bread. Oats are also an ingredient in many cold cereals such as muesli and granola.  They can be consumed raw or cooked. Ground Oats are also used in several different drinks, popular in Central and South America. In Britain, Oats are used in brewing beer, such as Oatmeal Stout.  


Oats are also commonly used as a thickener in soups in Scotland, much as barley or rice might be used in other countries. Oats can be ground into a fine flour.  It also can be used in the production of milk substitutes. 

Medicinal Uses

Well known as a calorie-dense food source, Oat plants often are neglected for their medicinal applications. Both their Milky Oat tops and Oatgrass stems are a valuable medicinal resource. 


“Milky Oats” refers to the immature Oat seed heads when they are in the “juicy” or milky state.  This is a fleeting stage, but one that can be captured and preserved in alcohol. Milky Oats are used for their nervine relaxant and trophorestorative effects, as well as their nutritive demulcent and libido-enhancing properties. Milky Oats rebuild the nervous system through their ability to regenerate the myelin sheath of nerve fibers. The effects of milky Oats are felt shortly after regular dosing, usually within a few days or a week of regular consumption. It is considered a more immediate treatment specific to people who are going through acute nervous exhaustion. People who benefit from Milky Oats are often characterized as people who have been going going going for far too long and are “burnt out”. It is often used to support those quitting smoking or experiencing other drug withdrawal. Eclectic herbalists used it for “heat weakness” that was directly associated with nervous system debility. 


Dried Oat straw, while also having an effect on the nervous system works differently.  Oat straw is rich in minerals and silica that support the long term health of the nervous system as well as help to strengthen bones, hair, teeth, and nails. Best results are achieved through using it for several months or even years. Oat straw works to strengthen and soothe nerves by balancing endocrine function and nourishing the immune system. It is believed they help foster physical, emotional, and mental health and resilience. Milky Oats, on the other hand, do not contain a lot of minerals and would not be used to support integumentary health. Dried Oatstraw is used very differently than the milky immature seed heads, though it is often sold in stores as interchangeable which is inaccurate. The best way to extract the minerals in Oatstraw is by strong decoction–simmer a generous portion in water for twenty minutes.


The entire Oat plant is considered one of the more mineral-rich herbal medicines. The mineral-richness of the plant makes it a specific for the treatment of osteoporosis due to the high amounts of Calcium and Magnesium. This also lends itself to women transitioning into menopause and older life, assisting with the depression that can often accompany this transition, restoring vitality, increasing sexuality and libido, strengthening bones, lowering blood pressure and decreasing the severity of hot flashes. 


The term “sowing your wild Oats” hints at Oats use as a “love potion”, supporting sexual health and increasing libido by nourishing the endocrine system and regulating hormones, moistening glands and restoring nerve health. “Love potions” often tend to support heart health and Oats’ reputation as a hearty-healthy, cholesterol-lowering food is well known.


The rich and hydrating milky nature of Oats can also be of benefit when used externally to soothe skin conditions such as poison ivy, chicken pox and other stress-related skin conditions.  Many skin lotions and body care products include Oats as an ingredient. Acting as an emollient, the herb can be soaked in water and used as either a formication or poultice or as a soak in the bath. 


Oats, Oatstraw, and Milky Oats are safe for everyone, from babies to pregnant or nursing mothers to elderly folks. The only contraindication is for people with celiac disease. 


The wild ancestor of Oats (A. sativa) and the closely related minor crop A. byzantina is the hexaploid wild Oat, A. sterilis. Genetic evidence shows the ancestral forms of A. sterilis grew in the Fertile Crescent of the Near East. Oats likely were developed from the “weeds” of the cereal crop that spread westward into cooler, wetter areas that were more favorable for Oats, eventually leading to their domestication in regions of the Middle East and Europe. Oats were introduced from Europe into North America for agricultural purposes. 


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