How to Grow Arugula From Seed

Arugula is a fast, cool-season green, so timing matters more than fuss. Direct-sow it in early spring as soon as the soil can be worked, then again in late summer for a fall crop. Because it grows so quickly, a single sowing is soon spent, so scatter a fresh pinch of seed every 2 to 3 weeks. Avoid sowing in the heat of midsummer, when arugula bolts and turns bitter.

Arugula dislikes being transplanted, so sow it right where it will grow, in the ground, a raised bed, or even a window box. It isn't fussy, but it grows fastest and mildest in rich, moisture-retentive soil, so rake in some compost first and level the bed. Sow the small seeds shallow, only about a quarter inch deep: scatter them in a wide band for baby-leaf cutting, or in rows about 10 inches apart for full-size plants. Keep the soil evenly moist and seedlings will pop up in about 5 to 7 days. Once they have a few true leaves, thin them to about 6 inches apart and toss the tender thinnings into a salad. For a steady supply, sow a fresh short row every 2 to 3 weeks.

Arugula practically grows itself in cool weather, and the one thing you most control is water. Keep the soil consistently moist and the leaves stay tender, mild, and quick; let it dry out and they turn tough and peppery-hot while the plant hurries to bolt. Mulch lightly to hold that moisture, and in warm spells give a little afternoon shade to slow bolting. It is a leafy crop, so a gentle boost of balanced feed keeps growth lush, but go easy: too much nitrogen, like too much heat, pushes it to flower. Flea beetles are the main pest, peppering young leaves with tiny holes, so lay a floating row cover over the bed at sowing and pick often to keep tender new leaves coming.

Arugula is a true cool-season green, and heat is what ends it: in hot-summer regions like Texas, the Southeast, and Southern California it bolts fast once daytime highs push past the mid-70s, so grow it in fall, winter, and early spring there. In the North and the Pacific Northwest, spring and fall are prime, and a shaded, well-watered spot can stretch the harvest into summer.

Arugula's main headache is flea beetles, so its best neighbors either lure pests away or draw in the good bugs. These four all earn their place beside a bed of greens, and you can add any of them in one click:

Start picking as soon as leaves reach 2 to 3 inches, usually two to three weeks in. Harvest in the cool of the morning and take the outer leaves first, cut-and-come-again, so the center keeps producing. Younger leaves are mild and nutty; older ones grow peppery and bold. The flowers are edible too and make a pretty, spicy garnish.

Arugula's peppery, nutty bite wakes up all kinds of food. Pile the fresh leaves into salads with shaved parmesan and lemon, scatter them over hot pizza or pasta just before serving, tuck them into sandwiches, or blitz them into a sharp, garlicky pesto. Use the youngest leaves raw and the bolder older ones lightly wilted.

• Flea beetles: tiny shot-holes in young leaves. Cover seedlings with floating row cover and plant radish or nasturtium nearby as a decoy.
• Bolting and bitterness: heat and long days send arugula to flower fast. Sow in spring and fall, keep it moist, and pick the leaves young.
• Damping off: seedlings collapse in cold, soggy soil. Sow in well-drained soil and avoid overwatering.