Spinach - Key Growing Information
CULTURE: Spinach grows in a wide range of soils if moist and fertile but is sensitive to acidity; pH should be at least 6.0, preferably 6.5–7.5. Spinach germinates best in cool soil. Begin sowing in early spring as soon as the ground can be worked. Summer sowing in soil over 85°F (30°C) risks low or erratic germination. If sowing must be done during warmer weather, irrigating can help cool the soil and improve germination. Sow in mid-to-late summer for a fall harvest. Spinach can also be planted from late summer through the winter in protected structures for fall, winter, and spring harvest, though growth rates are much slower. Using floating row covers offers additional winter protection.
TRANSPLANTING: While direct seeding is customary, some growers choose to transplant their spinach, especially using the Paperpot Transplanter. Transplanting can help ensure full stands if germination has been difficult, either because of warm soil temperatures or diseases like damping off.
DIRECT SEEDING: For baby leaf: sow 3–5 seeds/inch in rows at least 2" apart. For bunching and full size: sow 10 seeds/ft., 1/2" deep in rows 12–18" apart.
SUCCESSION PLANTING: For a continuous supply, sow every 7–10 days.
HARVEST: For baby leaf: harvest with a knife when leaves reach desired size in 3-5 weeks, depending on time of year and speed of growth, making sure to cut above the basal plate for cut-and-come-again harvests. A second cut is possible by choosing appropriate varieties in all the seasonal slots. Triple-rinse leaves, sort out cut and broken leaves, and package. For full size: Harvest with a knife by cutting the long stems just above the basal plate, or, for whole-plant harvest, cutting just below the basal plate. When growing winter spinach, harvest largest leaves and allow the smaller ones to size up for later harvests. Full-size spinach can be sold as loose leaves or bunched.
STORAGE: Store at 32°F (0°C) and 95% relative humidity for 10–14 days.
AVG. SEEDING RATE: For baby leaf: 1M/25', 25M/125', 1,200M/acre at 40 seeds/ft. in rows at least 2" apart. For full-size leaves: 10M/1,000', 290M/acre at 10 seeds/ft. in rows 12–18" apart.
SIZED SEEDS: Standard except where noted.
SEED SPECS: SEEDS/LB.: 24,800–45,800 (avg. 38,800).
PACKET: 1,000 seeds; sows 25' baby, 100' full size.