How to Grow Spinach from Seeds

Spinach is one of the first veggie crops to plant in the springtime. It’s incredibly easy to grow. Your efforts get rewarded with an abundant harvest of highly nutritious spinach leaves in as little as four weeks. Keep reading to discover essential tips and tricks about how to grow spinach from seed.

Spinach (Spinacia oleracea), is part of the Amaranthaceae plant family with Swiss chard, quinoa, and beets. Like most other leafy greens, spinach is a cool-season crop. It grows best in the early spring and fall seasons when temperatures are lower. It’s rich in vitamins A, B, C, and K, calcium, iron, magnesium, and potassium.

In most cases, gardeners can enjoy spring and fall harvests of tasty spinach greens. Spinach tolerates temperatures as low as 20℉ but tends to bolt when it gets hotter than 75℉. In regions with hot summers, plant spinach seeds as soon as you can work the soil in early spring.

How to Grow Spinach from Seeds

Spinach is a fast-growing crop, and most types are ready to harvest within 35-45 days from planting seeds. Since it grows best in cooler weather, plant spinach seeds for your spring harvest when the soil temperature is consistently over 45℉.

To determine when you should plant spinach seeds, you’ll need to know when the typical last frost date for your zone is. Sow spinach seeds about four to six weeks before that date or whenever the soil is warm enough. However, keep in mind that germination usually takes longer in cold ground.

When choosing a planting location, ensure that your garden soil is well-draining and rich in organic matter. Spinach plants tend to be heavy feeders, so adding compost to your soil before planting helps provide nutrients for the developing seedlings. Plant spinach alongside other cool-season veggies like broccoli, cabbage, cauliflower, radishes, and turnips.

Planting Spinach Seeds

Timing is crucial when growing spinach from seed. If you sow the seeds too late, your spinach plants are likely to start bolting or prematurely growing flowers and going to seed before you get much of a harvest.

In most cases, it’s best to plant spinach seeds directly in your garden beds or containers. The plants grow quickly enough that starting them indoors isn’t usually necessary.

In climates with late spring frosts, it’s beneficial to use a cold frame for a few weeks after planting to give your spinach seedlings a favorable head start. Similarly, protecting the plants with a cold frame in mid to late autumn is an easy way to further extend your growing season.

About a week before sowing spinach seeds, cover your planting area with a layer of compost or dark-colored mulch to warm it up ahead of time. The ideal soil temperature for spinach seed germination is between 50-60℉.

Soak the seeds in water for 12 hours to break down their hard, protective outer coating for faster germination rates. Do so several days before planting and allow them to dry completely.

Sow groups of two or three spinach seeds a half-inch deep and cover them over loosely with soil. Spacing between each group of seeds should be about one inch. Gently water them in and keep the soil moist while the seeds germinate. The spinach seedlings will typically begin sprouting in approximately five to ten days. It can take up to three weeks in colder temperatures.

Spinach Plant Spacing

Once the seedlings grow to about two inches tall, thin them out, so the spacing between each plant is three or four inches. If there were any gaps where your spinach seeds didn’t germinate, it’s easy to transplant the seedlings you thin out elsewhere.

When transplanting spinach seedlings, keeping as much of the root system intact as possible is critical. Use your fingertip to press a one-inch-deep hole into the soil, place the roots inside, and gently press the surrounding soil around the stem.

Optimal Growing Conditions for Spinach

For the best possible results, grow spinach in well-draining, nutrient-rich soil. Choose a location with a minimum of four to six hours of direct sunlight throughout the day.

Fertilize spinach plants regularly throughout the growing season with an all-purpose organic fertilizer. If you prefer using liquid fertilizer, compost tea, or fish emulsion, apply it every two or three weeks according to the instructions printed on the product label. Apply granular fertilizer every four to six weeks.

While spinach plants require consistently moist soil, it’s also vital not to overwater. The plants are sometimes susceptible to fungal diseases, which are more likely in wet conditions. Mulch around your spinach plants to retain moisture and keep the surrounding soil insulated once the weather starts warming up.

Periods of drought or especially hot weather cause spinach plants to bolt, meaning they cease leaf production and send up a flower stalk. At this point, the leaves turn tough, bitter, and inedible. For a steady supply of fresh spinach leaves, try succession planting seeds every two weeks through early to mid-summer and harvest the whole plant before it bolts. Sow more spinach seeds in late summer once the weather starts cooling off for a fall harvest.

How to Grow Spinach Seeds in Containers

If you don’t have space for a veggie garden or raised beds at home, don’t worry. Spinach is ideal for container gardening. Plant spinach seeds directly in the pot or purchase nursery-grown spinach seedlings from your local garden center.

Select a container that’s at least six inches wide by six inches deep and has several drainage holes at the bottom. Fill it with rich, well-draining potting soil up to an inch below the rim. Pre-saturate the soil, then sow your seeds a half-inch deep and cover them loosely with soil.

If you’re transplanting spinach seedlings, rest assured that it’s pretty straightforward. Create a planting hole that’s slightly larger than the plant’s root ball. Add one teaspoon of all-purpose, organic fertilizer to the bottom of the hole, gently place the root ball inside, and fill it back in with soil. Thoroughly water the new plants immediately afterward.

Maintain consistently moist soil, but never let it stay soggy. Place your spinach pots in a sunny, sheltered location outdoors. Alternatively, grow your spinach indoors on a sunny, south-facing windowsill.

Harvesting and Storing Spinach

Depending on which variety of spinach you’re growing, the leaves are ready to harvest in about 35-45 days. You can begin harvesting the outer leaves once a rosette forms, with at least six leaves measuring two inches long. Baby spinach greens tend to have a sweeter flavor than the larger, more mature leaves.

Pick spinach leaves within a week of sprouting for the best overall taste and texture. Harvest the whole spinach plant before it begins bolting, and the leaves start turning bitter and yellow.

Spinach usually stays fresh for up to 10 days when refrigerated. Wrap the stems in a damp paper towel, then store your spinach in a container or perforated plastic bag in the crisper drawer.

If you have a large quantity of spinach at the end of the season, freezing it is a perfect way to extend its shelf life. Blanching isn’t required as long as you use your frozen spinach within six months.

Solutions for Common Pest and Disease Problems

Although it’s usually quite simple to grow spinach, there are a few signs of pest and disease issues to monitor for. Plants are considerably more susceptible to attacks from pathogens and insects when they’re stressed. Their best defense is receiving adequate amounts of light, nutrients, and water.

Aphids, leaf miners, spider mites, snails, and slugs are some of the most commonplace insects that feed on spinach plants. To get rid of aphids, leaf miners, and spider mites, spray all parts of the affected plants with an organic insecticide like insecticidal soap or neem oil. Spreading diatomaceous earth or mulching with coffee grounds and crushed eggshells works to deter slugs and snails. Protect your plants with floating row covers in early spring to prevent insects from laying eggs on the tender seedlings.

Spinach plants are prone to downy mildew, powdery mildew, and rust. Fungal diseases like mildew and rust spread quickly and are most prevalent in warm, moist environments. Ensure that your plants have proper air circulation and water with drip irrigation or a soaker hose to keep the leaves dry. Treat any affected plants with an organic copper or sulfur fungicide. Immediately remove infected leaves, practice regular crop rotation, and select disease-resistant spinach varieties.

Best Types of Spinach

One of the best parts of growing your own veggies is that there are so many unique varieties to try that aren’t usually available at the farmer’s market or grocery store. Spinach cultivars get classified as savoy (curly-leaved), semi-savoy, and flat-leaf. Here are some of the best kinds of spinach to plant in your home veggie garden.

Top Spinach Varieties

• Bloomsdale (heirloom, savoy, dark green leaves, bolt-resistant, disease-resistant, 40-48 days to harvest)
• Catalina (hybrid, semi-savoy, dark green oval leaves, heat-tolerant, disease-resistant, 40 days to harvest)
• Gazelle (hybrid, flat-leaf, dark green oval leaves, bolt-resistant, disease-resistant, 40-45 days to harvest)
• Red Cardinal (hybrid, flat-leaf, bright green leaves with red veins and stems, best for baby greens, 25-35 days to harvest)
• Tyee (hybrid, semi-savoy, dark green leaves, heat-tolerant, disease-resistant, 30-40 days to harvest)

Although some cultivars are more heat tolerant than others, spinach tends to bolt in hot weather. Try growing similar leafy greens with better heat tolerance like Malabar spinach (Basella alba) or New Zealand spinach (Tetragonia tetragonioides) in climates with hot summer temperatures. Although they’re different plant species, they both have a similar flavor and texture to true spinach. They sometimes get called “summer spinach.”

If you’ve been thinking about planting spinach seeds in your home garden, rest assured that it’s quite simple and well worth the effort. Spinach makes an outstanding addition to the veggie garden for beginner growers and experienced green thumbs alike. This leafy green superfood is low-maintenance, fast-growing, and highly nutritious. You’ll be harvesting tasty spinach greens in as little as four weeks.

Do you have any questions or comments about growing spinach from seeds? Please share them in the comments! If you enjoyed learning how to grow spinach from seed, please share these gardening tips with your fellow gardeners.