Spinach is an incredibly versatile vegetable that is also easy to grow at home!
Starting spinach from seed in fall or early spring is a great way to kick off your garden for the year. While 1 seed per hole will suffice when using fresh seeds, it’s best to place 2 or 3 seeds in each hole if you’re unsure of their age or quality.
Planting more than 1 spinach seed per hole can sometimes feel like a waste. But keep in mind that even the freshest seeds rarely have a 100% germination rate!
With that said, how many spinach seeds per hole you plant is only part of growing this leafy green. If you want your fridge to overflow with spinach this year, you’ll also need to pay close attention to things like temperature and overall soil quality.
How To Grow Spinach From Seed
Choose A Location
Spinach requires partial to full sunlight to thrive.
Since excess heat can cause spinach plants to bolt (flower) early, it’s a good idea to select a location with some available shade. Alternatively, you can plant taller plants alongside your spinach to shelter it from the sun’s heat.
Prep The Soil
Spinach grows best in soil containing plenty of organic matter. This organic matter boosts water retention and provides a slow stream of nutrients throughout the growing season.
Before sowing spinach seeds, prepare the soil by mixing it with compost or another organic fertilizer.
Aim for a soil pH between 6.5 and 7.0 for the best results.
Sow your spinach seeds ½-inch deep, being sure to fully cover each hole. Depending on the age and quality of your seeds, place up to 3 seeds in each hole.
Spinach can be grown in straight rows or scattered.
Space holes approximately 2 inches apart. If planting spinach in rows, leave between 12 and 18 inches between each row.
Spinach seeds can take up to a month to germinate in cool weather. Meanwhile, seeds sown when the soil is close to 70°F may germinate in a matter of days.
Allow seedlings to reach 2 inches tall. Thin out seedlings growing from the same hole by hand. Be careful not to damage the plant you intend to keep!
Continue thinning out the seedlings so that they are approximately 3 to 4 inches apart. Alternatively, you can wait until the leaves are the size of a quarter and then harvest the extra plants for baby spinach.
When Is The Best Time To Plant Spinach?
Spinach is a cold-season vegetable. This means that it grows best in the spring or fall.
According to the Old Farmer’s Almanac, spinach should be sown when the soil is between 40°F and 70°F. Most varieties require at least 6 weeks of temperatures in this range to grow properly.
If your winters are mild, then the best time to plant spinach seeds is in early fall or late winter. It’s possible to harvest spinach twice per year using this schedule.
Spinach grown in colder climates does best when planted in spring or early fall. You can sow spinach in autumn to be harvested in early spring as long as you protect the plants from the cold.
Which Spinach Varieties Are The Most Heat-Tolerant?
Gardeners in warmer climates will have greater success with heat-tolerant spinach varieties like ‘Corenta,’ ‘Spinner,’ and ‘Indian Summer.’
Malabar spinach and New Zealand spinach are two alternatives that handle the heat quite well. Although these plants are not related to “true” spinach, their leaves are extremely similar.
How To Collect Spinach Seeds
If this is your first year planting spinach from seed, then you’ll need to source your seeds from a garden center or similar retailer.
But if your garden already houses a healthy spinach crop, you can collect seeds to sow the following year.
Most spinach varieties have separate male and female plants. While both sexes produce flowers, only female spinach plants will produce seeds.
After your spinach has bolted and flowered, you’ll notice small green balls appear under some of the plants’ leaves. These plants are female (Plants with yellow balls are male).
You can allow the spinach to die off while remaining in the garden bed by withholding water until the plants dry out.
If withholding water isn’t an option — it likely won’t be if your spinach is grown alongside other veggies — then you can cut the female spinach plants at their bases and hang them to dry.
Once dry, the spinach seeds can easily be removed from the stems by hand.
Before you can store your spinach seeds for future planting, the outer husk must be removed. The best way to do this is by placing the seeds in a pan and shaking them around.
You can then blow the extremely lightweight husks away, leaving behind bare seeds.
How Long Do Spinach Seeds Last?
Vegetable seeds are not viable indefinitely. Fortunately, spinach seeds tend to be fairly long-lived compared to other popular veggies!
For the best results, spinach seeds should be used within 3 years of collection.
While some spinach seeds will germinate after 6 years or more, the germination rate probably won’t be great.
If you want to use older spinach seeds in your garden, consider planting several per hole (you might also want to place the holes closer together) and thinning out the seedlings as needed.
Can You Grow Spinach With Other Plants?
Yes, spinach is a wonderful option for companion planting! Planting your spinach seeds alongside other vegetables can help deter pests, improve soil health, and make the most of your available acreage.
Choose plants that complement the growth habit and needs of spinach. Some popular options include:
- Beans and Peas — Legumes are often used in companion planting because they improve nitrogen availability in the soil. You can use climbing beans or peas to create shade for your spinach plants.
- Tomatoes — Most tomato plants take much longer to mature than spinach. You can start these vegetables at about the same time. After your spinach is harvested, the tomatoes will continue to grow and fill out the newly empty space.
- Peppers — Peppers make excellent spinach companions for the same reasons tomatoes do! Be sure to select larger pepper varieties that won’t be smothered by fast-growing spinach.
- Onions and Garlic — Since spinach roots are fairly compact, there’s plenty of room in the soil to plant edible bulbs. Plant onions and garlic in the same bed as your spinach to maximize your annual harvest.
- Radishes — Radishes attract leaf miners, keeping them far away from your spinach. You can still harvest radishes damaged by leaf miners (the same certainly isn’t true of damaged spinach plants!).
How Many Spinach Seeds Per Hole – Final Thoughts
Growing spinach from seed is all about timing. As long as you plant your seeds when the soil temperature is right, you’re sure to have a bountiful harvest.
Even in perfect conditions, however, there’s no guarantee that all of your spinach seeds will germinate. Planting up to 3 spinach seeds per hole will ensure that your kitchen has a steady supply of leafy greens.
And if all of your spinach seeds do manage to germinate, you can harvest the extras as baby spinach early in the year!