USDA Zone 6 extends across a wide area of the central continental United States, from the mid-elevations of the Intermountain West and across the Ohio River Valley eastward to southern New England. This zone designation is less important than frost dates when growing spinach. Sow spinach seeds when the soil is not frozen, but cool -- anywhere from 35 to 60 degrees Fahrenheit. Spinach plants will survive frosts and light freezes down to a temperature around 25 degrees. Once the weather regularly warms above 75 degrees, spinach quickly flowers and withers away.
Spinach plants do not survive the harsh subfreezing temperatures in winter across U.S. Department of Agriculture Plant Hardiness Zone 6 where average minimum temperatures drop to zero to minus 10 degrees. However, the cool months of spring and fall provide ideal growing weather for spinach in the zone. As long as day length isn't too long and soil temperatures too warm, spinach seeds germinate, creating create plants large and leafy enough for harvest within seven weeks.
USDA zone 6 extends across a wide area of the central continental United States from the midelevations of the Intermountain West and across the Ohio River Valley eastward to southern New England. This zone designation is less important than frost dates when growing spinach. Sow spinach seeds when the soil is not frozen, but cool, anywhere from 35 to 60 degrees. Spinach plants survive frosts and light freezes down to a temperature about 25 degrees. Once the weather regularly warms above 75 degrees, spinach quickly flowers and withers.
Winter Growing Options
Sow spinach seeds in the garden in late winter in Zone 6 once the soil is workable. This occurs about Feb. 1 to March 1. Depending on variety, maturation times range from 20 to 40 days. Make successive sowings every seven to 14 days for a continual supply spinach greens maturing across the rest of spring. Do not sow spinach seeds after April 1. For a fall crop, begin sowing seeds between Aug. 15 and Sept. 1. Cease successive sowings just before Halloween.
Sowing Spinach Seeds
Spinach grows best in a fertile, crumbly soil that is moist but well drained. It tolerates a wide range of soil types, but avoid highly acidic soils. Create a planting furrow in a row that is 1/2-inch deep. Scatter seeds into the furrow, one seed every inch. Space additional furrow rows 12 to 18 inches apart. If you want baby leaf spinach, clipping off all leaves on plants only 2 to 4 inches tall, make the planting furrow ½ inch deep but 4 to 6 inches wide. Scatter seeds all over the furrow bottom with seeds 1/2 to 3/4 inch apart.
For precise timing of spinach sowing in your part of USDA zone 6 regardless of climate or elevation, contact the local cooperative extension office. Publications and horticultural agents provide pertinent scheduling and cultural tips for growing spinach in your region's soils and seasonal weather patterns. Ideal spinach planting times vary across zone 6 from Washington State to Oklahoma, Kentucky or Connecticut.
- University of Illinois Extension; Spinach; Ron Wolford, et al.
- "Sunset Western Garden Book"; Kathleen Norris Brenzel, editor; 2007
- University of Kentucky Cooperative Extension Service; Home Vegetable Gardening in Kentucky; Richard Durham, et al.
- Oklahoma Cooperative Extension Service; Greens Production; J.E. Motes, et al.
- Photo Credit Hemera Technologies/PhotoObjects.net/Getty Images
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