Spinach is a cool-season hydroponic leafy green for NFT, raft, ebb-and-flow, or drip systems, producing tender baby or mature leaves when the root zone stays.
Identification
Growth habit: Cool-season leafy annual grown as a compact rosette for tender leaves before bolting.
Leaves: Leaves are green, oval to arrow-shaped, and may be smooth, lightly crinkled, or heavily savoyed.
Flowers: Plants bolt under heat, long days, or stress, producing upright flower stalks.
Edible Parts
Leaves: Harvest baby leaves young or cut larger outer leaves while leaving the crown for regrowth.
Tender stems: Young petioles and tender stems are commonly eaten with the leaves.
Propagation
Seed: Sow seed in cool, moist starter plugs or shallow media; germination declines in heat.
Cultivation
Nutrient film technique: Well suited if solution temperatures stay cool and flow is reliable.
Deep water culture: Works well in raft systems with good aeration, clean water, and cool root-zone temperatures.
Ebb and flow: Suitable in plugs or shallow media beds when moisture remains even.
Lookalikes
Swiss chard: Related leafy crop with larger leaves and thicker colorful or white petioles.
Beet greens: Similar young leaves, especially at seedling stage.