21 January 2011, written by Barbara Pleasant
Gardeners love a lush bed of spinach, but sometimes their dreams don’t come true when they plant spinach. From what I’ve seen, the hardest part is getting all the spinach seeds to sprout at once, like little soldiers. Sometimes I get uniform sprouting, with rabbit-eared seedlings at just the right spacing for easy thinning. But more often I’ll see gaps in rows, and spotty germination often plagues my indoor flats, too. When I plant spinach seeds in the garden in the spring or fall, or when I start some indoors early in the season, I’ve learned to pay close attention to every little thing.
Let me take a moment to talk about starting spinach seeds indoors, which is a great thing to do in late winter. Some people say that spinach can’t be moved, but I think that young seedlings with two true leaves are just as easy to move as any other vegetable, as long as you make sure the plants don’t get too stressed. In my garden, this means having a rich bed ready, with a plastic tunnel, a glass window frame, or some other kind of fence around it to keep plants safe. I can pick garden-fresh spinach before the last frost because I use spinach seedlings to extend the spring season.
It is possible for spinach seeds to sprout very slowly at temperatures close to freezing, but they do best at 60–68°F (15–20°C). This is another reason to start your first garden spinach of the year indoors. As the weather warms in spring, you can direct-sow a second planting. I like to plant spinach seeds every other day in the spring and pull out the faster-growing lettuce when the spinach needs more space to grow. You can also alternate rows of spinach with onions, which make good garden companions. Upright onions don’t crowd the spinach, and the spinach helps shade out weeds between rows of onions.
Many sources say that spinach seed can be used for three years, but I’m not going to depend on a reference chart to tell me if my planting will work or not. If spinach seeds are more than two years old, I throw them away and buy one or two packets of fresh spinach seeds every spring.
Still, I’ve seen huge differences in how quickly spinach seeds from different sources sprout. Of course, it could just be me. Spinach seeds germinate in three steps: first they soak up water, then new cells grow inside the seed, and finally the radicle, or sprout, comes out. The rate of spinach germination is higher and more even when the second stage lasts a little longer in an oxygen-rich environment, before the seeds grow into full sprouts.
Scientists call this process “priming,” and it’s easy to do at home. About a week before planting, soak spinach seeds in room temperature water for 24 hours. Put the wet seeds on a paper towel and leave them at room temperature for one or two days to dry. Shift the seeds to an airtight container, and keep in a cool place for up to a week. The primed seeds will retain enough moisture to complete the first two stages of germination. When planted, primed spinach seeds sprout in just 5 days, while seeds that aren’t primed take 10 days or more to sprout.
To get a good stand, you need to spoil your garden spinach. The same tips you use in the spring to help spinach sprout also work in the fall. When it gets hotter than 75°F (23°C), spinach stops wanting to sprout. That’s why I prime some seeds before starting them indoors in August and direct-sow a winter crop when it gets cooler in the fall. When it comes to a vegetable like garden spinach that is tasty, useful, and good for you, four plantings a year is plenty.
As a quick-growing, nutrient-dense green, spinach is a must for any veggie garden Getting a healthy stand of spinach starts with proper germination, so understanding how long spinach seeds take to sprout is key
In this complete guide, we’ll cover everything you need to know about spinach sprouting times, plus tips to speed up and improve germination.
What Factors Affect Spinach Germination?
Several key factors influence how quickly spinach seeds will sprout:
Soil Temperature
-
Spinach seeds germinate best at soil temperatures between 45-75°F.
-
At cooler temps below 40°F, germination slows down significantly.
-
Temperatures above 80°F inhibit germination
Soil Moisture
-
Spinach needs consistently moist soil to sprout.
-
Allowing seeds to dry out delays or prevents germination
Seed Freshness
-
Older spinach seeds up to 3 years old will still germinate but more slowly.
-
For fastest sprouting, use fresh seed packs purchased for the current growing season.
Seed Priming
-
Priming seeds by pre-soaking speeds up sprouting time.
-
Dry, unprimed seeds take longer to sprout than primed ones.
What’s the Fastest Spinach Germination Time?
Under ideal warm soil temperatures between 60-70°F, fresh primed spinach seeds can sprout in as little as 2-4 days.
However, these perfect lab-like conditions are hard to achieve in real garden soil.
A more realistic sprouting timeframe is 5-10 days for spinach seeds sown directly in prepared garden beds in spring or fall.
Spinach Germination Stages
Spinach seeds sprout in three basic stages as moisture is absorbed and cells grow and divide inside the seed:
1. Imbibition
The seed coat swells up as moisture is absorbed. This prepares the seed for germination.
2. Cell Growth
Cell growth and division occurs, producing the root and shoot internally.
3. Emergence
The radical (root) emerges from the seed coat and anchor into the soil. Next, the hypocotyl (shoot) grows upward toward sunlight.
Priming tricks seeds into completing the first two stages before planting. Then seeds quickly move to emergence when sown in soil.
Tips for Faster Spinach Germination
Here are some useful tips to improve your spinach seed germination time:
-
Test soil temperature and wait until it reaches 45°F before planting.
-
Use fresh seeds no more than 1-2 years old.
-
Prime seeds by soaking in water for 12-24 hours before planting.
-
Plant seeds 1⁄2 inch deep in loose, well-drained soil.
-
Water soil regularly to keep moist, not soggy wet.
-
Cover seeded beds with burlap until sprouts emerge.
-
Start seeds indoors at 70°F for transplanting outside later.
What Do Spinach Sprouts Look Like?
Spinach sprouts emerge from the soil as two small green leaves, called cotyledons or seed leaves. These first baby leaves are oval or spade shaped.
The stem rapidly elongates, producing the spinach plant’s first true leaves which are smooth, bright green, and more rounded with a tapered shape.
Spinach is ready to harvest after 3-4 sets of true leaves emerge, about 4 weeks after sprouting. Leaves can be cut starting when plants reach 2 inches tall.
How to Grow Spinach from Sprouts to Maturity
Once your spinach seeds have successfully sprouted, follow these tips for growing the plants to maturity:
-
Thin seedlings to 2-6 inches apart about 2 weeks after sprouting.
-
Water 1 inch per week. Avoid water stress.
-
Side dress with compost or fertilizer when plants are 3-4 inches tall.
-
Mulch to conserve moisture and deter weeds.
-
Row covers prevent insect pests like leaf miners and aphids.
-
Harvest outer leaves regularly, allowing inner leaves to continue growing.
-
Watch for bolting in warm weather and harvest whole plants before flower stalks elongate.
With the right care, your homegrown spinach can be ready to start harvesting in as little as 4-6 weeks from sowing seeds.
Troubleshooting Spinach Germination Issues
If your spinach seeds are slow to sprout or fail to emerge, here are some common issues to troubleshoot:
-
Cold soil – Spinach needs warm soil, at least 45°F to sprout well. Use a soil thermometer and wait for warmer temps.
-
Old seeds – Spinach seeds over 3 years old have lower germination rates. Always start with fresh seed.
-
Improper planting depth – Sow seeds 1⁄2 inch deep. Seeds buried too deep won’t sprout well.
-
Dry soil – Ensure consistent moisture to prevent the seeded bed from drying out.
-
Damping off disease – Fungal disease kills sprouts. Avoid overwatering and increase sunlight.
-
Rodent pests – Mice and voles eat seeds and seedlings. Use hardware cloth to line beds.
-
Weed competition – Aggressive weeds steal water/light from spinach sprouts. Keep beds weed-free.
With a little patience for optimal soil temperatures and proper planting techniques, you can look forward to a healthy crop of homegrown spinach. Check your seeded beds daily so you can witness those first tiny sprouts emerging!
Plants Related to this Article
If you need help designing your vegetable garden, try our Vegetable Garden Planner.
Grow Spinach – Seed to Harvest
Do spinach seeds need light to germinate?
Spinach seeds do not need light to germinate, but once they sprout, the seedlings will need light to continue growing. Fifth, make sure to plant your spinach seeds according to the proper depth and spacing. Spinach seeds should be planted at a depth of 0.5 inches (1.3 centimeters). If planting in rows, put 12 to 15 seeds per foot.
How long does it take for spinach seeds to germinate?
Spinach seed germinates in 5 to 9 days at 70°F (21°C). Soak spinach seeds in compost tea for 20 minutes before sowing to speed germination. Sow seed 2 to 4 inches (5-10cm) apart and space rows 12 to 14 inches (30-35cm) apart.
How long does it take to grow spinach?
It takes about 30-50 days to grow spinach from the time you plant the seeds to when you can expect a sizable harvest. However, you can usually start picking small amounts before then.
How do you grow a spinach plant?
To grow a spinach plant, sow seeds 1/2 of an inch deep every 2 inches and cover with 1/2 inch of soil. Plant in rows 12 to 18 inches apart or sprinkle over a wide row or bed. Sow seeds every couple of weeks during early spring for a continuous harvest. Keep the soil constantly moist and use row covers to maintain cool soil and deter pests.
