Spinach (Spinacia oleracea) is an edible plant species that is often considered a ‘superfood’ due to its high content of vitamins, folate, fiber, iron, magnesium, and other nutrients. Spinach is grown in gardens around the world and provides an important food source.
I. Appearance and Characteristics
Spinach (Spinacia oleracea) is a leafy green flowering plant native to central and Western Asia. It is of the order Caryophyllales, family Amaranthaceae, subfamily Chenopodioideae.
Originally from Persian aspānāḵ, the name entered European languages from Latin spinagium, which borrowed it from Arabic isbanakh. The English word “spinach” dates to the late 14th century from OF espinache.
As opposed to the great majority of the flowering plants or plants used as vegetables, spinach is a dioicous plant, meaning different plants can have either female or male flowers.
The flowers are small, green and unattractive to pollinators. Rather, pollination occurs via wind anemophily, for which the pollen has evolved to be very small and light so it can be carried large distances, often miles away.
Spinach is thought to have originated about 2,000 years ago in ancient Persia from which it was introduced to India and later to ancient China via Nepal in 647 AD as the “Persian vegetable”. In AD 827, the Arabs introduced spinach to Sicily. The first written evidence of spinach in the Mediterranean was recorded in three 10th-century works: a medical work by al-Rāzī (known as Rhazes in the West) and in two agricultural treatises, one by Ibn Waḥshīyah and the other by Qusṭus al-Rūmī. Spinach became a popular vegetable in the Arab Mediterranean and arrived in the Iberian Peninsula by the latter part of the 12th century, where Ibn al-ʻAwwām called it raʼīs al-buqūl, ‘the chieftain of leafy greens’. Spinach was also the subject of a special treatise in the 11th century by Ibn Ḥajjāj.
Spinach first appeared in England and France in the 14th century, probably via Iberia, and gained common use because it appeared in early spring when fresh local vegetables were not available. Spinach is mentioned in the first known English cookbook, the Forme of Cury (1390), where it is referred to as ‘spinnedge’ and ‘spynoches’. During World War I, wine fortified with spinach juice was given to injured French soldiers with the intent to curtail their bleeding.
II. Types of Spinach
- Disease-resistant varieties include ‘Melody’, ‘Nordic IV’, ‘Olympia’, ‘Tyee’, and ‘Wolter’.
- Good varieties for fall planting include ‘Avon’, ‘Indian Summer’, ‘Melody’, ‘Razzle Dazzle’, and ‘Tyee’.
- Plants that overwinter well include ‘Bloomsdale Long Standing’, ‘Cold Resistant Savoy’, and ‘Tyee’.
- Recommended types for containers include ‘Baby’s Leaf Hybrid’ and ‘Melody’.
III. How to Grow and Care
Sunlight
Plant spinach where it will receive full sun to partial shade. That means it needs at least three to four hours of direct sun on most days, though it could use some protection from strong afternoon sun.
Temperature and Humidity
Spinach prefers to grow in temperatures between 50 and 60 degrees Fahrenheit. It can tolerate a light frost, but heavy freezes will kill the plant. Plus, hot weather will make it bolt and cause the remaining foliage to become bitter. Humidity typically isn’t an issue as long as its soil moisture needs are met and there’s air flow around the plants.
Watering
Water spinach frequently to keep the soil evenly moist but not soggy. Regular watering is essential in warm weather to prevent bolting. In general, spinach needs around 1 to 1 1/2 inches of water per week. Rather than a weekly deep watering, it’s better to water several times a week. Adding a layer of mulch around the plants also can help to maintain soil moisture.
Soil
Spinach likes a loamy, organically rich, well-draining soil. And it prefers a fairly neutral soil pH.
Fertilizing
Because it is such a fast grower, spinach is also a heavy feeder. When planting, mix a fertilizer that’s high in nitrogen into the soil, following label instructions. This will help to promote healthy foliage growth. Continue to fertilize throughout the season, following your product’s instructions. Fish emulsion and soy meal are good organic choices for spinach.
How to Grow in Pots
Growing spinach in containers is a great way to keep it easily accessible for harvesting. And it can help to deter pests from munching on your crop. Choose a container that’s at least 10 to 12 inches deep with a similar width. You also can use a window box for a few plants, depending on their mature size. The container must have drainage holes. Unglazed clay is an ideal material because it allows excess soil moisture to escape through its walls. Note that containers tend to dry out faster than the ground, so you’ll likely have to water container plants more frequently.
Pruning
Harvesting the leaves throughout the growing season is how you prune a spinach plant to keep it vigorous. If a plant becomes diseased or damaged, it’s often best to pull the whole plant to prevent it from affecting nearby plants.
Mulching
To keep weeds at bay and the soil moist, lightly mulch with grass clippings or straw, taking care not to smother the plant.
Propagation
Spinach typically is grown from seeds, but it’s also possible to propagate plants from stems you pull that still have roots attached. (Taking stem cuttings typically isn’t successful.) This skips the germination time that seeds take, allowing you to get a quicker harvest. Here’s how:
- As you harvest from mature spinach plants, find a stem that has roots. Gently pull it out of the ground, keeping the roots as intact as possible.
- Plant the stem in a quality potting mix, and water to maintain even moisture.
- Once you feel resistance when gently tugging on the stem, you’ll know a strong root system has formed.
How to Grow From Seed
Aim to plant spinach seeds that are less than a year old, as the germination rate falls the older seeds get. You might have to till your soil before planting, as spinach likes a loose, fine soil. Firm the soil over the seeds, and water to evenly moisten it. Make sure to keep the soil moist during the germination process, and you should see growth in a week or two.
Potting and Repotting
Use an organic, all-purpose, well-draining potting mix for spinach. It’s best to pot in a container that will accommodate the plant’s mature size, as spinach doesn’t like its roots disturbed in repotting.
Overwintering
In warm climates, you might be able to sow seeds in the fall and harvest well into winter. If the ground freezes before the plants mature, mulch them with hay and leave them be until the temperatures warm again in the spring. Remove the mulch, and the plants should resume growing, giving you an early harvest.
Pests and Diseases
Because spinach is grown when the weather is cool and damp, several fungal diseases, such as downy mildew (blue mold) and fusarium wilt, can become problems. Space your spinach plants so they get good air circulation, and try to keep water off the leaves in the evening.
Aphids also pose a risk to spinach because they can spread viruses. Monitor your crop for aphids regularly, and hose them off immediately if you find them. Plus, wild animals, rabbits chief among them, also might raid your spinach patch. The best defense against them is fencing.
IV. Uses and Benefits
Ornamental uses
Spinach is an annual plant prized for its ability to grow in the cooler months in the spring and fall. It is commonly used for its edible properties and is an essential plant in vegetable gardens. Plant it with cucumbers, tomatoes, peppers, squashes, and herbs for texture and a steady supply of fresh produce.
Culinary uses
Spinach is eaten both raw, in salads, and cooked in soups, curries, or casseroles. Notable dishes with spinach as a main ingredient include spinach salad, spinach soup, spinach dip, saag paneer, pkhali, and spanakopita.
Health benefits
- It brings down Blood Pressure. A high potassium content guarantees optimal potassium levels and aids in reducing sodium’s adverse effects on the body, reducing the risk of high blood pressure.
- Fighting cancer. All green vegetables include chlorophyll, which prevents heterocyclic amines’ ability to cause cancer (things we consume when foods are grilled at high temperatures).
- Management of diabetes. Alpha-lipoic acid, an antioxidant in spinach, has been demonstrated to lower blood sugar levels, improve insulin sensitivity, and guard against oxidative stress-related alterations.
- An essential component of strong bones is vitamin K. It modifies the proteins that make up the bone matrix, enhances calcium absorption, and might lessen calcium excretion through the urine.
- One of the best sources of magnesium is spinach, which is necessary for a healthy immune system and normal muscle and neuron function, including heart function and Metabolism. Iron also makes your body utilize energy more effectively, giving you more of it.
- Hair and Skin. Sebum, which is required for hair hydration and the development of all human tissues, including new skin and hair, is made possible by vitamin A. Collagen gives skin and hair their fundamental structure, and vitamin C aids in its synthesis and synthesis maintenance.
- Boosts Metabolism In spinach, these little sacs called thylakoids contain chlorophyll and reduce cravings and hunger. It, together with spinach’s low-calorie content, makes it the perfect diet food.
V. Harvesting and Storage
Typically, you can harvest spinach four to six weeks after planting seeds. Begin harvesting whenever the leaves are large enough for your taste. Spinach can be harvested in the “cut and come again” method. Trim off individual leaves with garden scissors, starting with the oldest outer leaves and letting the young inner leaves remain to continue growing for a later harvest. You also can cut down the whole plant at once if you want a large harvest. If you cut about an inch above the crown, or base of the plant, it is likely the plant will send out a new flush of leaves.
Spinach can be eaten fresh or cooked. The leaves are sensitive to ethylene gas given off by many fruits, so don’t store spinach in the refrigerator in the same container as apples, melons, or tomatoes. Keep it in an airtight container on its own. Spinach also can be frozen for later use. Wash the leaves well, and allow them to dry before placing them in a freezer bag. Frozen spinach is best used within three to six months.