Spinach Germination

Winter

• Gardeners can prepare their planting site in the fall before snow falls for winter planting. Spinach seeds may be distributed over snow cover, so that they germinate in the early spring when the temperatures rise, according to the University of Illinois. To prepare the soil for spinach seeding and germination, remove all debris from the old harvest and weeds. Use a broad spectrum herbicide that contains glyphosate, so that there is little toxic residue to impede germination.

Late Winter

• Gardeners may sow their spinach seeds indoors six weeks before their last frost date, according to Mother Earth News. The last frost date for your area depends on the region. For example, the last frost date for Denver, Colorado is April 30th while the last frost date for Mobile, Alabama is February 28th. Before sowing your seeds in a planting tray, soak the seeds for 24 hours to help germination, as suggested by the Texas Gardener. Plant your seeds in the seed trays at a depth of 1/4 of an inch. Plant your spinach transplants outdoors after the last frost date.

Spring

• Spinach seeds have difficulty germinating in warm soil. The optimal soil temperature for germination is under 75 degrees Fahrenheit, according to the Texas Gardener. Gardeners may sow their spinach crops as long as their soil doesn't exceed 75 degrees Fahrenheit in the spring. For a continual harvest, sow successive crops every couple of weeks in the spring. When temperatures heat up, switch to warm season vegetables until the late summer to early fall to sow your spinach seeds.

Late Summer

• Measure your soil temperature with a soil thermometer in the late summer to early fall. As soon as temperatures dip below 75 degrees Fahrenheit, start sowing your spinach seeds. To sow seeds, plant 12 to 15 seeds per square foot and at a depth of 1/2 an inch. Thin the spinach plants to 2 to 4 inches apart when they have grown to a height of 2 inches. Spinach plants take roughly 39 to 48 days to grow before they are ready to harvest.