Spinach
Spinach
Harvest Type: Continuous or single harvest
Transplant/Direct Sow: Direct sow over transplanting
When to Plant: 4-6 weeks before the last average frost date. For fall gardens, sow or transplant 6-8 weeks before the first average frost date.
Days to Germinate: 5 days
Days to Maturity: 35-45 days
Planting Depth: ½ -1”deep
Germination Temp: Minimum 40°F. Optimal range is 60-70°F.
Seed Spacing: 12-15 seeds per foot. Thin to 3” apart when seedlings are 2” tall.
Light: Full sun
Soil pH: 6.5-7. pH
Water: 1-1 ½” of water per week
Soil Temperature: Warmer soil is better than cool soil.
Fertilizer: 10-10-10 N-P-K ratio
Rotation: Annually with other leafy greens.
Harvest Type
Spinach can be a single harvest crop or a continuous harvest crop. For cut-and-come-again plantings, spinach production is continuous.
TIP: To increase yield, use a liquid fertilizer at the plants' base and practice successive gardening.
Transplant / Direct Sow
You can direct sow or transplant spinach seeds. However, spinach is a cool-loving plant, so it makes more sense to sow seeds directly. For fall gardening, you can start spinach seeds indoors to avoid the hot summer temps and then transplant them outdoors to your fall garden around the first day of fall.
When to Plant:
In spring, plant spinach when the soil temperature is 60-68°F. Spinach seeds will not germinate in temperatures over 85°F.
TIP: Use successive growing to produce a continuous spinach crop throughout spring and early summer and again for fall and winter gardening. Use Row Cover to protect it from harsh freezes.
Days to germinate
It takes spinach seeds about 5 days to germinate.
Days to maturity
It takes about 35-45 days for plants to mature, depending on the variety you plant.
Planting Depth
Plant seeds at 1/2-1" deep.
Germination Temperature Range
Spinach germinates when the soil is as cold as 35°F but does poorly. Aim for a soil temperature of 60-68°F for spinach and keep in mind that spinach seeds will not germinate in soil temperatures above 85°F. These are not hot-weather plants.
Spacing Between Plants
Plant 10-15 seeds per foot of row space, or sow thickly and then thin to 2-4" apart.
Growing conditions
Spinach needs nitrogen-rich soil. Use a 10-10-10 N-P-K fertilizer or dig in aged compost to 18". Water spinach often and do not allow the soil to dry out completely. Keep the soil moist without getting the leaves wet. Spinach is a spring and fall crop and will not do well in the heat of summer or the deep cold of winter. A cold frame is a good tool for early spring planting.
Companion Plants
Beets, kale, lettuce collards, greens, Tetsoi, bok choy, and carrots are excellent companion plants for spinach. You can grow short-term plants with plants that take longer to mature. Grow spinach with tomatoes as you will harvest the spinach before the tomatoes become too tall.
Rotation
Rotate spinach and other leafy greens each year.
Anticipated yields
Plan your garden yield at 15-18 spinach plants per person for daily consumption, and expect 4-7 pounds of spinach for each 10-foot row segment. Planted at 4" apart, that's about 30 plants per 10' row. Successive planting will extend the growing season and keep you well supplied with spinach. For successive planting, plant seeds 2-3 weeks apart for a single harvest and 1-2 weeks apart for daily snipping.