What Does "Slow to Bolt" Mean When Planting Spinach Seeds?

Spinach leaves harvested in cooler temperatures yield the best taste.

A cool-season leafy vegetable crop, spinach grows best and has the best flavor when harvested while temperatures are between 40 and 70 degrees Fahrenheit. Bolting refers to the production of the tall flower stem on spinach plants.

Significance

The long daylight hours and warm temperatures of spring do not produce flowers as quickly in "slow to bolt" or "long standing" varieties of spinach. Leaf production and flavor is best when the spinach plant remains a low tuft and the elongating flower stem doesn't develop.

Time Frame

Spinach needs between 40 and 65 days to germinate from seed and start producing leaves large enough for a substantial harvest. It may be sown either in early spring or in early fall to take advantage of cool, light frosty conditions.

Potential

You may extend your harvest season for slow-to-bolt spinach by planting it early in spring, as soon as the soil is workable, then planting successive rows of spinach in increments of 10 to 14 days. This produces flushes of leaves throughout spring. Incremental planting in fall is more difficult because late fall's hard freezes eventually kill plants.

References

• University of Illinois Extension: Spinach

Resources

• Mother Earth News: All About Growing Spinach