Vegetable of the Month: Spinach (Spinacia oleracea)
March 19, 2025
By Rick Bogusch
Native to central and west Asia, spinach has been cultivated as a vegetable for over 2,000 years. It originated In Persia and from there was introduced to India and China. It also became very popular as a green in North Africa and the Middle East and was introduced to Sicily, and later, in the 12th century, to the Iberian Peninsula. By the 14th century, its use spread to Europe where it was enjoyed as one of the first vegetables of spring. With colonization of the New World, cultivation of spinach became global. In the past 3 years, the world produced over 33 million tons of spinach annually, most of it grown in China. The United States produces 200 million tons every year, most of it in Texas, Florida and California. About a quarter of that is harvested for fresh use and the rest is processed.
Like beets and chard, spinach is a member of the amaranth family. Usually an annual, it often overwinters and behaves as a biennial, flowering in its second year. Basal leaves, the leaves we harvest and eat, can grow up to a foot tall, but are usually much smaller. From them, arise taller flowering stalks, triggered by the lengthening days and warming temps of late spring and early summer. Spinach plants are either male or female. Flowers are greenish yellow, inconspicuous and wind-pollinated, ripening into a dry cluster of seeds at the top of the stem.
Spinach is rich in vitamins and minerals, and is a highly nutritious addition to soups, salads, casseroles, savory pies around the world. Frozen spinach often has a higher nutritional value than fresh, because spinach loses vitamins and minerals after just a few days. That’s why so many gardeners like to grow their own.
Spinach is easily grown. It can even be grown in containers, providing they hold a gallon or so of soil and are 4-6 inches deep. Consistently moist, fertile soil is all spinach needs for good growth. The more nitrogen you give it, the more it will produce. Though it prefers full sun, it will also grow well in partial shade, with 3-4 hours of sun per day. In hot climates and in the warm days of early summer, afternoon shade prolongs harvest, but spinach grows best when daytime temperatures are in the 60’s and 70’s, not the 80’s and above.
Sow seed directly in the garden, 1/4 -inch deep, as soon as soil can be worked in March or April. Harvest leaves 4-6 weeks after sowing by cutting to the base. Spinach can be harvested continuously or cut all at once. If fertilized generously with fish fertilizer after each cutting, a row of spinach can be harvested 2-3 times.
Sow spinach at the end of the season, too, in September, for a fall harvest and/or to overwinter for an early cutting the following spring. Very frost-tolerant, surviving temperatures of 20 degrees and below, spinach can be covered in late December with frost blankets or placed under grow tunnels to ensure an early crop.
There are many varieties of spinach. Some have deeply crinkled or savoyed leaves, prone to collecting dirt and debris and hard to clean. Some have smooth, arrow-shaped leaves. Some are best grown in spring and some, like the extra-large, Asian varieties, grow best in fall. Some, like the popular ‘Space’ variety grow well in both seasons. Whichever you choose, growing spinach is easy and rewarding.
Rick Bogusch
Garden Director, Bridge Gardens
rbogusch@peconiclandtrust.org