Devotion to the cool-season green known as spinach (Spinacia oleracea) didn't begin and end with Popeye. This nutritious leafy vegetable has a long culinary history. Modern spinach types possess different characteristics that make them suited to a variety of kitchen and garden goals, but all types ask for the same basics:
- Give true spinach a location with full sun and well-drained soil with near-neutral soil pH.
- Direct sow seeds into cool spring soil as soon as soon as the garden can be worked.
- Sow again every two to three weeks for successive harvests.
- Water throughout the growing season, so soil stays consistently moist.
- Mulch spinach plants to conserve moisture and stabilize soil temperatures. Spinach's shallow roots dry out easily, and heat encourages bolting -- when plants flower prematurely and set seed, and leaves turn bitter.
- Plant again in late summer for fall harvests.
Spinach seedlings often don't transplant well, so direct sow for the greatest success. Don't delay spring planting -- the seeds germinate best before soil warms up. Seedlings tolerate temperatures down to 15 degrees Fahrenheit.
Some spinach varieties excel during certain seasons, regardless of type. Varieties prone to bolting do best when grown and harvested in cool seasons, while bolt-resistant varieties perform well during warmer months too. Five types of true spinach are widely cultivated, along with a few imposters that ride along on the name.
Also known as flat-leaf spinach, smooth-leaf types make up the bulk of commercial production intended for grocery sales and canned or processed foods . Smooth-leaf types grow very low to the ground -- which can make for muddy leaves -- but the broad, smooth leaves simplify cleaning and processing. Without the crinkles found in other spinach types, smooth-leaf spinach doesn't hold onto dirt, sand or wayward insects. Some outstanding cultivars include:
- 'Corvair' spinach (Spinacia oleracea 'Corvair'), with very dark green, smooth, oval leaves. Slow to grow and slow to bolt, it does well sown in spring for summer harvests.
(Spinacia oleracea 'Gazelle') has smooth, dark green leaves. Fast growing and quick to bolt too, it's good for late summer and fall plantings, and harvests from fall through spring, where growing conditions allow.
Low-growing savoy types have puckered, deep green leaves that can get muddy and sandy. Though harder to clean, they're favorites at farmers' markets where the attractive leaf texture stands out. Usually quite cold-tolerant, savoy leaves are perfect for crisp salads. Some top varieties include:
- 'Kookabura' spinach (Spinacia oleracea 'Kookabura') with dark and deeply crinkled, rounded leaves -- it's a fast grower with average bolting tendencies. It does well for both spring and fall planting, with harvests in early summer and again in fall to early winter.
- 'Harmony' spinach (Spinacia oleracea 'Harmony') is a fast-growing, early season variety that resists bolting. The heavily puckered, dark greens are very flavorful.
Semi-savoy spinach combines the best of both worlds. They grow taller and more upright, so there's less grit and grime, but they keep attractive, slightly crinkled leaves. Often recommended for beginners and home gardeners, these types generally resist bolting and disease. Some varieties include:
(Spinacia oleracea 'Emperor') with dark green leaves and moderate growth paired with moderate bolting speed. It does well in late-summer and fall plantings, with harvests through spring, where conditions allow.
- 'Reflect' spinach (Spinacia oleracea 'Reflect') offers medium green leaf color with a slight pucker. Slow to bolt, this medium-rate grower excels when planted in cool spring right through summer into cool fall.
With deep red stems and veins, these spinach varieties look a lot like common beet (Beta vulgaris) greens. They add a dash of color to salads along with classic spinach taste. Some colorful varieties include:
- 'Red Kitten' spinach (Spinacia oleracea 'Red Kitten') has smooth, medium green leaves with dark, burgundy-red, upright stems and veins. Fast to grow and fast to bolt, this variety suits cool fall planting best. Harvests continue through late winter to early spring.
- 'Bordeaux' spinach (Spinacia oleracea 'Bordeaux') delivers very dark green, red-veined leaves. It grows and bolts fast, but has an excellent, sweet flavor. Plant it in spring and again in fall.
Also known as Asian leaf or Oriental leaf, this spinach type has a classic arrowhead leaf shape, thick leaves and mild flavor. As a group, these types are very slow to bolt. Some varieties include:
- 'Flamingo' spinach (Spinacia oleracea 'Flamingo') has dark, green, arrowhead leaves and is fast to grow but not fast to bolt. Plant in spring, through summer and into fall, and enjoy harvests from late spring through to the following early spring.
- 'Summer Delight' spinach (Spinacia oleracea 'Summer Delight') is highly heat-tolerant and slow to bolt. It offers thick, dark green leaves that excel in spring and summer plantings. It's a great choice for warm climates.
Some popular greens go by the same common name as true spinach but have no botanical connection. Sow these heat-loving greens after your region's last frost date. These heat-tolerant greens make good substitutes for true spinach during summer heat. Examples include:
- New Zealand spinach (Tetragonia tetragonioides) is a warm-season green that tolerates hot summers and brings traditional spinach taste to the table.
- Red Malabar spinach (Basella rubra), also known as Ceylon spinach, is a vining, heat-tolerant green that looks beautiful on a trellis or arbor. The red-stemmed and red-veined beauty looks and tastes like a cross between spinach and chard (Beta vulgaris var. cicla).