Spinach
Also known as
Garden spinach, Common spinach, Persian spinach, True spinach
Keep this plant’s care guide close at hand.
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Spinacia oleracea, commonly known as spinach, is a cool-season annual leafy vegetable in the Amaranthaceae family. It forms a low rosette of tender, dark to medium green leaves that vary from smooth to savoyed depending on cultivar. Plants are typically dioecious (separate male and female plants), producing inconspicuous green flowers that are wind-pollinated, followed by small seeds (traditionally spiny, now often smooth in modern varieties). Spinach grows rapidly in cool weather and is prized for its mild, slightly mineral flavor and high levels of folate, vitamin K, carotenoids, and iron, as well as naturally occurring oxalates and nitrates. Shallow-rooted and sensitive to heat and long days, it tends to bolt quickly under warm conditions or drought stress. It thrives in fertile, well-drained soils with ample organic matter and consistent moisture. Best grown in early spring and fall, spinach is suitable for in-ground beds, raised beds, or containers, and is harvested by individual leaf picking or cutting whole rosettes before flowering.
Taxonomy
Properties & Requirements
How to care for Spinach
Water
Keep soil consistently moist but never waterlogged. Provide about 1–1.5 inches (25–38 mm) of water per week, adjusting for rainfall and sandy soils. Water in the morning at soil level to limit leaf wetness and reduce downy mildew risk. Mulch lightly with clean straw or compost to moderate temperature swings, reduce evaporation, and keep grit off leaves. Because roots are shallow, avoid allowing the top few centimeters to fully dry; even brief drought can trigger bitterness and bolting.
Light
Provide full sun in cool seasons (6+ hours daily) for best vigor and leaf production. In warming weather or hot climates, give partial shade—especially afternoon shade—or use 30–40% shade cloth to slow bolting and reduce leaf scorch. Spinach is sensitive to increasing day length; long days combined with heat speed flowering. Ensure good light in short days for sturdy rosettes, but manage light and temperature later in spring to prolong the vegetative phase and maintain tender leaves.
Nutrients
Spinach is a relatively heavy nitrogen feeder. Before sowing, incorporate well-rotted compost and a balanced starter (e.g., 5-5-5) into the top 10–15 cm of soil. Side-dress with a fast-acting nitrogen source (fish emulsion, blood meal, or diluted urea) 2–3 weeks after emergence, and again if leaves pale. Avoid overfertilizing, which can encourage excessive nitrate accumulation and tenderness loss. Maintain soil electrical conductivity on the low side and avoid high-salt fertilizers; keep pH near neutral for optimal nutrient uptake.
Temperature
Spinach thrives in cool conditions, with ideal growth between 50–65°F (10–18°C). Seeds germinate well from 40–75°F (4–24°C), with fastest, most uniform emergence around 50–60°F (10–16°C). Plants tolerate light frosts and short dips to about 20–25°F (−6 to −4°C), especially when hardened. Heat and long daylength accelerate bolting; sustained temperatures above ~75°F (24°C) reduce quality. In warm climates, grow in late fall to early spring, or provide shade and consistent moisture to moderate canopy temperature.
