Spinach is a popular green to grow in gardens, but it’s also an ideal vegetable to plant in pots. The compact plants don’t need a lot of root space and they’re very quick to go from seed to harvest. Growing spinach in containers just outside my kitchen door means I’ve always got a supply of the tender leaves on hand for salads and cooked dishes. The key to success for cultivating spinach in pots is to pick the best types of containers, fill them with a rich growing mix, and provide consistent moisture. Below you’ll learn everything you need to know about growing spinach in containers. Read on!
Why grow spinach in containers?
Spinach is a cool-season crop related to Swiss chard and grown for its succulent deep green leaves. Depending on the variety, spinach leaves can be smooth, semi-savoy, or super crinkly with the plants growing 6 to 12 inches tall. This is an easy-to-grow crop, but does have specific requirements. If these needs are not met, spinach plants are quick to bolt. Bolting is when plants switch from vegetative growth to flowering which means an end to the harvest. For gardeners who have little garden space, poor or infertile soil, or garden on a deck, balcony, or patio, growing spinach containers is an effective solution.
When to plant spinach in containers
Spinach grows best in cool temperatures and is an ideal crop for spring and fall. In fact, spinach is one of the first crops I plant in early spring, direct sowing my first batch of seeds 6 to 8 weeks before the last expected frost date. This vegetable can be planted when the soil reaches 45 degrees F (7 degrees C). In warm climates, spinach is grown as an autumn and winter crop.
Because we love spinach, I plant more seeds every couple of weeks to provide a continual harvest. As spring turns to summer and the temperatures regularly climb over 80 degrees F (26 degrees C) I stop planting spinach as it doesn’t grow well in hot dry weather. Instead I switch to heat-tolerant greens like amaranth, New Zealand spinach, and Malabar spinach.
By late summer the days are getting shorter and the temperatures are cooling down. That means the time is right to start planting spinach once again. My first late season sowings begin 6 to 8 weeks before the first fall frost date. These plants continue to produce leafy greens until late autumn. If placed in the shelter of a greenhouse or cold frame, pots of spinach can last well into winter, even in northern climates.
What types of containers should you use for growing spinach
When it comes to pots and planters, there are lots of choices. I’ve grown spinach in plastic pots and buckets, wooden window boxes, and fabric planters. It’s important that whatever type of container you use has drainage holes so excess rain or irrigation water can drain away. If your pot doesn’t have drainage holes, it’s easy to add them to plastic or wooden containers using a drill fitted with a quarter inch bit.
You’ll also want to consider pot size. Spinach plants produce a taproot as well as a fibrous root system. If you’re growing spinach for baby greens, a 6 to 8 inch pot is deep enough. If you want large mature spinach plants, pick a container that is 10 to 12 inches deep.
The best soil when growing spinach in containers
Give your spinach plants a strong start by filling the containers with a blend of potting mix and a source of organic matter like compost or rotted manure. I like to use roughly two-thirds potting mix and one-third compost. Spinach needs a growing medium that is well-draining, but also holds moisture. If the plants are allowed to dry out they’ll bolt. Adding organic matter like compost increases the moisture holding capacity of the potting soil.
I also add a slow-release organic vegetable fertilizer to the growing mix. This supplies nitrogen, phosphorous, potassium, and other nutrients. If you prefer, you can apply a liquid fertilizer like fish emulsion or manure tea every 2 to 3 weeks instead of using a granular product.
How to plant spinach in pots
Once you’ve picked your containers and filled them with your growing mix, it’s time to plant. It only takes a minute or two to plant spinach in pots. The seeds can be direct sown or started indoors. I prefer to direct sow, but there are benefits from giving spinach a head start indoors. Learn more below.
- Direct seeding spinach – Spinach seed germinates in about 5 to 10 days, depending on the temperature, and the seedlings are quick to size up. I plant spinach seeds one quarter to one half inch deep in pots. They’re spaced 1 to 2 inches apart, and I eventually thin them to 2 to 3 apart for baby leaves. I prefer growing container spinach as a baby crop. For full-sized plants thin spinach to 4 to 6 inches apart.
- Starting spinach seeds indoors – Spinach has a reputation of being difficult to transplant so most gardeners direct sow seeds outdoors. That said, I find spinach does transplant well as long as the seedlings are hardened off and moved to the garden while still small. Spinach germination can sometimes be spotty when direct sown and transplanting ensures a full bed of greens – no empty spots. Start the seeds indoors 3 to 4 weeks before you intend to harden off and transplant the seedlings. I plant in a seed tray under my grow lights. The young plants are best moved to pots when they have two sets of true leaves.
Growing spinach in containers
Once your spinach seeds sprout, there are a few things to keep in mind to promote a heavy crop of succulent leaves. Here are 3 tips for growing spinach in containers.
1) The most important task is watering
Spinach grows best when the soil is lightly moist. When you grow spinach in pots you’ll need to water more often than a crop that is planted in the ground. Check the growing medium daily, deep watering if it’s dry to the touch. I use a watering can or long handled watering wand to saturate the soil of my spinach pots.
Why is it necessary to pay attention to soil moisture? Drought-stressed spinach plants are prone to bolting. This is when the plants stop producing new leaves and instead form a central flower stalk. When spinach bolts, the leaves turn bitter and unpalatable. It’s best to pull the plants and add them to your compost pile. Keeping spinach well irrigated can slow bolting. So can applying a mulch like straw around plants.
2) Spinach grows best with 6 to 8 hours of full sun each day
Spinach will grow in partial shade, with just 3 to 4 hours of sunlight, but growth is slower. Providing some shade can be beneficial, however, particularly if growing spinach in late spring or summer. Giving the plants relief from the hot mid-day sun can delay bolting which means you can enjoy the tender leaves for an extra week or two.
3) Succession plant for the best harvest
I practice succession planting in my raised beds and the containers on my sunny deck. Once a pot of spinach has germinated and the seedlings are a couple of inches tall, I start another pot. By the time all of the spinach from the first container is harvested, the second pot is ready to eat.
If you want to learn more about growing spinach in containers, watch this video:
When to harvest spinach
As noted above, spinach is a fast growing green and baby leaves are ready to harvest just 30 days from direct seeding. I start to pick mature leaves about 38 to 50 days from sowing, depending on the variety. You can pick individual leaves by hand as they reach a harvestable size or you can cut the whole plant. I prefer to pick the outer leaves, waiting to pull up the entire plant until I see that it’s beginning to bolt. Baby greens are picked when they’re 2 to 4 inches long. Mature leaves are ready when they’re 4 to 10 inches long. It’s easy to tell when spinach begins to bolt as the plant begins to grow upwards and a flower stalk emerges in the center of the leaves.
Eat harvested spinach immediately or wash and dry the leaves, storing them in a plastic bag in the refrigerator. Use the leaves within a few days.
The best spinach varieties to plant in containers
I love growing all types of spinach for salads, pastas, casseroles, dips, and steaming. Here are three of my top spinach varieties to grow in pots.
- Bloomsdale – Often called Long Standing Bloomsdale, this classic variety is among the most popular grown in home gardens. The deeply crinkled leaves are thick and dark green and you can pick them when immature or as the plants reach their full size.
- Seaside – I started growing Seaside spinach a couple of years ago and fell in love with the vigor of this slow-to-bolt variety. The compact, deep green leaves are perfect for growing in pots. I harvest Seaside as a baby salad green and love the mild spinach taste.
- Space – Space is a reliable variety perfect for spring, autumn, and winter harvesting. The smooth, rounded leaves are resistant to common spinach diseases and ready to pick just 25 to 30 days from seeding.
I’ve also had excellent success growing Regiment, Red Tabby, and Oceanside spinach in pots.
Problems when growing spinach in containers
Spinach is fairly trouble-free, especially when you provide ideal growing conditions – cool temperatures, rich soil, ample moisture, and sunlight. However pests like slugs, aphids, or leaf miners can sometimes be an issue. If you spot holes on the leaves, take a closer look for insect pests. I hand pick slugs and knock aphids off the plants with a hard jet of water from my hose.
Diseases like downy mildew or leaf spot are not uncommon. Keep an eye for yellow or discolored leaves. Aim to water the soil, not the plants to reduce the spread of soil-borne diseases. Providing plenty of light and not overcrowding spinach also helps to minimize spinach diseases.
For more information about growing vegetables in containers, be sure to check out these in-depth articles:
- How to grow tomatoes in a self-watering planter
- Growing watermelons in pots
- How to plant and grow carrots in containers
- Tips on growing garlic in pots
Are you going to be growing spinach in containers?