Botanical and Regional Identities
Both rocket and cress are cruciferous vegetables, meaning they are part of the Brassicaceae family, which also includes broccoli, kale, and cabbage. However, they are different species within this large family. The confusion often stems from their similar pungent, peppery taste and their common use in salads.
What is Rocket?
Rocket, known as arugula in the United States, is an annual plant with the scientific name Eruca sativa. It originates from the Mediterranean region and is characterized by its lobed, jagged-edged leaves. Other names for rocket include rucola and roquette. Wild rocket (Diplotaxis tenuifolia) is a related perennial species with a stronger flavor. The distinctive peppery flavor of rocket is due to chemical compounds called isothiocyanates.
What is Cress?
Cress is a broader term that encompasses several different plants, most of which are also in the mustard family. The two most common types are Garden Cress and Watercress.
- Garden Cress (Lepidium sativum): Also called peppergrass, this fast-growing herb has small, tender green leaves with a mildly spicy, peppery flavor. It is often grown for microgreens and sprouts, reaching harvestable size in a matter of weeks. Its leaves have a simpler, less-indented shape than rocket.
- Watercress (Nasturtium officinale): This aquatic plant features small, round to oval, clover-like leaves. It is known for its more intense, pungent, and peppery flavor compared to rocket. Watercress is winter-hardy and grows naturally in flowing water.
Appearance, Flavor, and Culinary Applications
While both greens offer a peppery bite, their physical and sensory characteristics differ, influencing their best culinary uses.
Appearance
- Rocket: Has distinctively lobed, jagged-edged leaves that can be light or dark green depending on the variety and age of the leaf. Younger leaves are often smaller and milder, while older leaves are larger and more pungent.
- Garden Cress: Possesses small, delicate, and often curled or deeply cut leaves, which are typically lighter green.
- Watercress: Characterized by its tiny, lily-pad-shaped leaves and edible stems. It forms dense mats of greenery, especially when grown in water.
Flavor Profile
- Rocket: Features a strong, peppery, slightly nutty, and sometimes bitter flavor. The intensity can vary, with wild rocket being notably spicier than garden rocket.
- Cress (Garden & Watercress): Both are peppery, but watercress is generally considered to have a more potent, sharper flavor, often described as mustard-like. Garden cress is milder than watercress.
Culinary Uses
Both are versatile salad greens but excel in different applications.
How to Use Rocket
- Salads: Rocket is a classic addition to mixed salads, providing a spicy, nutty counterpoint to milder leaves.
- Pizza Topping: It is often scattered over a pizza after it comes out of the oven to prevent wilting and retain its vibrant color and flavor.
- Pasta: A handful of rocket stirred into a warm pasta dish adds a fresh, peppery finish.
- Pesto: It can be used as the base for a zesty pesto sauce.
How to Use Cress
- Sandwiches: Garden cress is a classic ingredient in egg mayonnaise or cream cheese sandwiches, where its mild pepperiness cuts through the richness.
- Soups: Watercress is often blended into soups to create a creamy, vibrant green soup with a peppery kick.
- Garnish: Both types of cress are frequently used as a garnish for their delicate appearance and taste.
- Sprouts: Garden cress is a very popular choice for growing sprouts on damp cotton wool or tissue.
Key Nutritional Differences
While both offer significant health benefits, their nutritional profiles have some variances.
- Vitamins: Watercress is significantly higher in Vitamin K and Vitamin C than rocket. Rocket, however, boasts a much higher level of folate.
- Minerals: Rocket contains more iron, calcium, and magnesium than watercress, though both contain these minerals. Garden cress seeds are also notable for their high iron and calcium content.
- Fatty Acids: Garden cress seeds, in particular, are a good source of omega-3 and omega-6 fatty acids.
Comparison Table: Rocket vs. Cress
| Feature | Rocket (Eruca sativa) | Garden Cress (Lepidium sativum) | Watercress (Nasturtium officinale) |
|---|---|---|---|
| Appearance | Deeply lobed, jagged leaves | Small, delicate, often curled leaves | Small, round/oval, clover-like leaves |
| Flavor | Peppery, nutty, slightly bitter | Mildly spicy, peppery | Intense, pungent, peppery, mustard-like |
| Texture | Tender, but with more body than cress | Very delicate, quick to wilt | Crisp stems, tender leaves |
| Growth | Annual (garden rocket), Perennial (wild rocket) | Annual, fast-growing herb | Aquatic plant, thrives in moist conditions |
| Key Vitamins | High in folate, Vitamin A, Vitamin K | High in Vitamin C, Vitamin K | Very high in Vitamin K, Vitamin C |
Are There Other 'Rocket-Cress' Plants?
Another source of confusion comes from plants with hybridized names. For example, some plants are explicitly sold as "Rocket cress". This typically indicates a specific variety chosen to exhibit characteristics of both. Similarly, Yellow Rocket or Wintercress (Barbarea vulgaris) is a wild edible plant with a bitter, peppery taste, but it is a distinct species. The best way to be sure of what you are purchasing is to check the scientific name, which most responsible growers will provide. For information on types of rocket, check out the BBC Good Food glossary.
Conclusion
In summary, while frequently confused due to their similar spicy and peppery flavor profile, rocket and cress are not the same plant. Rocket (Eruca sativa) is a specific species known for its distinctively lobed leaves, while 'cress' is a more general term that includes separate species like the milder Garden Cress and the more pungent Watercress. Each offers unique visual, textural, and nutritional qualities that make them excellent additions to a variety of dishes. Knowing their specific characteristics allows home cooks and gardeners to choose the right green for their desired flavor and texture, enhancing their culinary creations with confidence. Both are delicious and nutritious members of the Brassicaceae family, proving that even closely related plants can have very distinct personalities.
