How to Grow Arugula Herb From Seed
- Latin Name: Eruca vesicaria sativa
- Other Names: Rocket, Garden Rocket, Roquette, Rucola
- Days to Maturity: Annual, 40-45
- Days to Germination: 7-10
- Planting Depth: ¼"
- Plant Spacing: 6-12"
- Plant Height: 6-12"
- Growth Habit: Leafy mound similar to mustard
- Soil Preference: Organic, rich, consistently moist
- Temp Preference: Cooler, 45-65°F
- Light Preference: Full sun - partial shade
- Pests/Diseases: Susceptible to flea beetles, slugs, and some smaller pests similar to lettuce
- Flavor: Shorter "baby" leaves are sweet and peppery while longer, more mature greens, share a similarly tangy spice to its relatives mustard and radish
- Benefits: Learn more about Arugula benefits
- Availability: See All Arugula Seed Varieties
Planting Arugula Seed
Arugula is one of the easier herbs to grow both indoors and out, quick to maturity and grown very similar to headless leafy lettuces. Arugula can be started indoors 4-6 weeks earlier for outdoor transplanting but, unlike some tender culinary herbs, may also be sown directly after the final spring frost. If sowing directly outside, plant 3-4 arugula seeds per hole 2-3” apart in consistently moist, organically rich, and well-drained soil with a pH of 6.0-6.8. Arugula thrives in cool spring weather with full sun but, in regions with overly warm summers, will benefit from partial shade. Once true leaves begin to establish, thin best starts to about 4” in the garden. Just like lettuce, arugula may be planted every 2-3 weeks for successive, season-long harvests up until the fall. Because arugula grows so quickly, prepare the soil with a nitrogen-rich fertilizer or organic compost before sowing, as this will be the only fertilizing necessary until harvest.
Growing Arugula in Pots
Like many culinary herbs, arugula thrives in containers and planters on the patio, in the garden bed, or indoors. Whereas arugula is often treated as a “cut and come again” herb, many starts may be grown per container for easy and accessible harvesting. The biggest benefit to growing arugula in a pot is that it makes for easy pest management while allowing you to move the container about the yard to best capture optimal sun and shade throughout the day. Arugula is susceptible to fungal diseases from poorly drained soils and can benefit from the reliable drainage of container gardening. However, soil in pots and containers are notorious for drying out faster than in the garden bed, and arugula must remain consistently moist to avoid bolting and bitter, underdeveloped greens.
Growing Arugula Indoors
Arugula is a fast-growing herb able to be grown to harvest indoors with a grow light or on a windowsill with plenty of sunlight. Except for microgreens and some short-lived greens, many plants are unable to thrive up until harvest with only indoor growing lights. However, because tender “baby” arugula is ready to harvest at about 3” long, it can be comfortably grown indoors year-round via soil-based methods or hydroponically. Whether growing as a microgreen or quick indoor crop, arugula is an ideal countertop grow, easily accessible by the chef in your life.
Growing Arugula Hydroponically
Grown very similar to lettuce greens, arugula has recently become a choice crop for hydroponic cultivation. Sometimes cultivated individually or in tandem with a variety of lettuces, arugula is popularly grown as part of a Mesclun mix of greens known for their quick harvests. Regardless of the particular hydroponic method, the water nutrient mix should still maintain a pH of 6.0-6.8 just as if being sown directly in garden soil. As mentioned, due to its speedy maturity, arugula is able to be grown to harvest entirely indoors with only the help of a grow light.
Arugula is most tender and delicious when about 2-3” long, otherwise known as “baby” arugula. Even the white blooms on more mature plants are plenty edible and delicious, still boasting the same sharp and peppery notes of tender leaves. Although arugula can continue to grow several feet in every direction similar mustard and collards, the greens will have by then become far too fibrous, coarse, and bitter for culinary use. Smaller outer leaves may be clipped individually for “cut and come again” harvesting or the entire plant can be uprooted for use, clearing garden space for additional seedings. Arugula greens will be far too bitter to consume if the plant has bolted and gone to seed in the summer heat.
Arugula Seed Pods
Because arugula is a weedy, short-lived annual always at risk of bolting to seed in the summer, it is one of the easiest and most reliable plants to harvest seed. Once arugula has overgrown its “baby” harvest stage, the plant will begin to spread vigorously and produce several white flowers for pollination. As these flowers begin to emerge, the plant will then begin to produce pea-like seed pods each containing about 10 seeds. Pods can be harvested when the plant is still green with vegetative growth or even well past the season after the plant has completely dried, brown, and looks more like a tumbleweed. As mentioned, arugula has a tenacious weed-like habit and will continue to reseed itself in the garden if allowed to grow unchecked.
Arugula Pests and Insects
If growing for quick harvests, then arugula does not spend that much time in the garden to be bothered by many pests such as longer-lasting Brassicas. However, arugula can be susceptible to flea beetles, often identified by chewed up holes left in the leaves often known as “shotholes”. While flea beetles may not necessarily chew away an entire crop, they make the arugula plant susceptible to a variety of diseases that could cause yellowing and infect nearby crops. Daily pest control is one of the biggest advantages to growing arugula in easily accessible pots and containers rather than the garden bed. Slugs and snails have also been known to eat away at arugula, but can usually be solved with a thin layer of diatomaceous earth added to the soil.
Growing Arugula Problems
Arugula is a cool-weather crop best suited for mild summers, always threatening to bolt to seed if not provided adequate shade in warmer regions of the country. One of the biggest problems to growing arugula is the development of various fungal diseases from poorly drained soil and lack of ventilation. As mentioned, arugula can benefit from the reliable drainage of patio pots and containers to help reduce excessive saturation. Since arugula is such a fast grow, infected or unsuccessful starts can be removed from the garden to allow for a new seeding. If allowed to flower and reach full maturity, arugula will heavily reseed itself in the garden year after year.
Arugula Companion Plants
Arugula thrives alongside legumes such as bean and pea because they both replenish the soil with essential nitrogen while providing shade if planted accordingly. Aromatic herbs and members of the fragrant Allium genus such as onion and garlic are commonly sown within proximity of arugula as it is widely believed that the robust aroma from these companion plants help to deter pests by creating a noxious and inhospitable garden.
Benefits of Arugula
While some herbs have a long and extensive history being used for a variety of medicinal and cultural practices, arugula has almost exclusively been used just as a culinary green treated nearly identically to headless leafy lettuces. Like many fresh garden vegetables, arugula is a nutrient-dense and low-calorie favorite traditionally featured in Mesclun mixes along with similar greens such as mustard, spinach, endive, and frisée.
Additional Information on Arugula Herb
- Arugula Wikipedia Page
- Read the Best Practices for Planning Your Herb Garden!
- Learn About Hardiness Zones
See all of these arugula seed varieties: