Grow Spinach from Seed

What are the secrets for growing spinach from seed successfully?

Many people struggle to get seeds to germinate, so I’d like to share a few tips for successfully starting seeds and supporting strong plant growth.

First, prepare the soil by incorporating generous amounts of organic matter. Next, mix in a fertilizer, such as Happy Frog Tomato and Vegetable Fertilizer or Happy Frog Marine Cuisine, before planting to give your seeds a strong start.

If your soil is heavy or retains moisture for long periods, start by planting seeds in raised beds using the “ridge and furrow” method.

Next, ensure your soil has adequate moisture before planting. If the soil feels dry, water it several days in advance. Avoid watering after planting but before germination, as this often promotes seedling diseases

How to prepare Spinach seeds for planting

First, prepare the seeds by placing them in a container filled with water. Then, set the container in your refrigerator for 24–48 hours before planting. During this time, the seeds absorb the cold water, which helps initiate germination. Consequently, spinach grows more successfully from seeds that have been soaked.

Spinach seeds germinate poorly in warm soil. Therefore, to ensure a strong stand, plant your first fall crop only when soil temperatures are 75°F or lower. Wait to sow spinach seeds until the soil has had a chance to cool.

“You can continue planting successively until about 6–8 weeks before temperatures are expected to drop near 20 degrees. Conversely, stop planting approximately six weeks before daytime temperatures are forecasted to average above 75 degrees.”

What should I expect after planting?

  • Depending on soil temperature, seedlings will emerge within 7–10 days. Once they appear, thin them approximately two weeks after emergence, spacing them 4–6 inches apart to allow healthy growth.

  • After another two weeks, apply a light dose of the fertilizer mentioned above to support continued development.

  • Throughout the growing period, maintain consistent soil moisture, since spinach feeder roots are concentrated in the top 8–10 inches of soil.

Do I need to protect plants from freeze?

If a hard freeze is expected (in the 20s), first mulch your plants 2–3 inches deep to protect them from the cold. After the freeze passes, pull back the mulch, and your plants will resume growth.

By following these steps, you can ensure a successful crop of nutritious spinach during the cool winter months.