Saving Spinach Seeds: A Complete Guide for Organic Growers

The process of saving spinach seeds may be meticulous, but it will prove valuable for next season's crops.


| March 17, 2014



Male and female organic spinach plants growing

Spinach is dioecious, with separate male and female plants. In this photo, a female plant with immature seed already forming is on the left and a robust vegetative male at peak flowering is on the right.


Photo by Scott Vlaun

With a high nutritional quality in all varieties, spinach plants are well-worth the patience and precision. Each plant will add color to your garden and nutrition to your plate, as well as produce an abundance of spinach seeds for the next planting season. IThe Organic Seed Grower (Chelsea Green Publishing, 2012), John Navazio combines traditional, organic know-how and the latest scientific research with the intent to place the organic growing power back where it started, into the hands of local seed growers and farmers. Because the knowledge of growing and saving seed is too important to leave to the agribusiness “experts," now is a great time to learn and begin growing. The following excerpt, from chapter five, “Amaranthaceae,” explains the process of growing spinach and saving spinach seeds.

Buy this book from the MOTHER EARTH NEWS store: The Organic Seed Grower.

About Organic Spinach Plants

Common name: spinach
Crop species: Spinacia oleracea L.
Life cycle: annual
Mating system: cross-pollinated
Mode of pollination: wind
Favorable temperature range for pollination/seed formation: 65–75°F (18–24°C)
Seasonal reproductive cycle: early to mid-spring through late summer or early fall
Within-row spacing: seed-to-seed 16–24 in (41–61 cm); root-to-seed 18–30 in (46–76 cm)
Between-row spacing: seed-to-seed 30–36 in (76–91 cm); root-to-seed 30–48 in (76–122 cm)
Species that will readily cross with crop: All spinach seed growers should be conscious of nearby farm or garden plots of spinach grown for fresh market production as these crops can flower rapidly in late spring and summer before they are turned under.
Isolation distance between seed crops: 0.5–3 mi (0.8–4.8 km), depending on crop type and barriers present on the landscape

Spinach (Spinacia oleracea) is one of the most widely grown vegetables in temperate climates around the world. It is derived from a leafy, winter annual that evolved in and near the Fertile Crescent of the Middle East. Winter annuals are plant species that germinate in the cool of the fall and grow vegetatively until the short days and cold of winter slow their growth. In spring, winter annuals grow steadily until a combination of environmental factors prompts the reproductive phase of the life cycle. Spinach bolting is initiated primarily by daylength, and the ancestral forms of this crop bolt very early in spring with less than 14 hours of light per day. This allowed the predecessor of modern spinach to mature seed before the onset of the intense heat of summer in the Middle East. The seed then lay dormant, having evolved to only germinate with the onset of cool, wet weather in fall, and thus the cycle was repeated.

Modern forms of this crop have been selected to produce a lush and robust leafy vegetable that is widely adapted across environments and seasons. Various types of spinach still produce well as a fall-sown vegetable that can be harvested in fall, winter, or spring. It is easily cold-hardy to 15 to 18°F (–9 to –8°C) but can survive much lower winter temperatures if insulated by snow. Many contemporary varieties have been developed to be spring-planted and produce a bountiful crop before the summer daylength causes bolting. Much recent breeding work has been devoted to develop fast-growing, upright plants that thrive at high population densities and are harvested at a juvenile or baby-leaf stage for bagged salads. Spinach leaf surfaces are smooth, semi-savoyed, or fully savoyed, depending on the amount of leaf curl. The savoyed curl is due to varied rates of growth of ground tissue parenchyma between leaf veins. Leaf shape ranges from the putative older form of triangular blade that is referred to as having an arrowhead or Christmas tree shape, characteristic of Asian spinach varieties, to the rounder, less lobed leaf that has become the ideal in European and North American markets. Selection for color in variable spinach populations has created darker leaf pigmentation. Research investigating the nutritional quality of spinach has found that the dark green types have higher levels of a variety of phytochemicals with antioxidants such as the carotenoid lutein, which is important for the health of the macula in the human retina.

Crop Characteristics

Reproductive Biology





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