Ah, spinach. One of the best vegetables to grow in the garden. Every year I allocate some space to spinach for salads. If you haven't tried it yet, let me encourage you to do so.
Spinach is a cool season crop and grows best in spring and fall. In warmer parts of the country, spinach can be grown in the winter. Using a cover over the growing spinach plants can protect them when the weather gets unexpectedly cold, and keep your crop growing even longer.
Spinach is easy to start from seed. Occasionally you can find starter plants at the garden center, but it's a lot less expensive to start from seed. Seeds are usually available year round.
Compared to lettuce seeds, spinach seeds are large, and they are typically light colored. This makes them easy to handle, another benefit.
Spinach prefers cooler weather and can be planted up to 6 weeks before the last frost date. Spinach plants can tolerate a light freeze.
Plant the seeds about a half inch deep in the soil, about 4 inches apart. Keep the soil moist and the seeds germinate in 5-7 days. Germination is better in cooler soil temperatures, meaning spinach planted in the warm soil of summer may not germinate well.
The spinach sprout has a distinctive appearance. The cotyledons, or the embryonic leaf of the sprout, are long, leggy, and thin. True leaves appear soon thereafter from the center of the plant, in the expected spinach leaf shape.
There are dozens of spinach varieties available, and you can try several to see which ones grow the best in your garden. The botanical name for spinach is Spinacia oleracea.
Spinach varieties tend to be categorized as "smooth leaf" (sometimes called "flat leaf") or "savoyed." Smooth leaf is exactly what you might expect. The leaf is relatively smooth and flat. Savoyed spinach has a "bumpy" texture, or "crinkled" appearance. Leaves may be described as heavily savoyed if they are very crinkly, semi-savoyed if they are slightly bumpy, or smooth. Most fresh spinach in grocery stores in the United States is smooth leaf. The texture of the leaves does not impact flavor or quality.
Leaves are generally in an oval or spade shape. Some varieties have a more arrowhead appearance, while others are more elongated. Some varieties have rounder leaves.
Varieties are primarily shades of dark green. A few more colorful varieties can be found such as Red-Veined Spinach and Red Tabby. My go-to spinach variety for the Till and Trowel garden is called Space Hybrid, a smooth leaf spinach with a medium dark green color. It grows very well in my zone 6 community garden plot.
Malabar spinach (Basella rubra) is not common spinach, although the flavor is similar. Malabar spinach is a vine that flourishes in the heat of summer and varieties are available with pretty red stems and pale green stems. Sometimes other greens will be called "spinach" because they are similar to spinach, but check the botanical name to be sure.
Spinach is grown for its leaves, and the leaves can be picked at just about any stage of growth. Younger smaller leaves tend to have milder flavor and tender texture. Like most greens, spinach will eventually bolt, and warmer weather especially encourages spinach plants to bolt.
Depending on the variety and size of spinach leaf you want, spinach will be ready to harvest in 3 to 5 weeks. The weather impacts the time to maturity, as well. If the weather is cooler, the growth is slower.
Spinach can be harvested in three different ways: cut and come again, or cutting off the entire plant at soil level, or pulling out the entire plant.
Cut and come again is a harvesting technique where individual, mature leaves are picked off the plant, but the plant is left in the garden.
Spinach plants grow close to the ground and accordingly, soil from the garden gets splashed on the leaves. It's important to wash your spinach thoroughly before eating or freezing.
Spinach leaves are delicate and the best technique to avoid damaging the leaves is to use a salad spinner.
Once the spinach leaves are clean, they are ready to use. They can be used fresh or cooked, depending on the recipe. If you want to preserve your spinach by freezing, consult a freezing guide. Spinach is usually blanched before it is frozen.