Brussels sprouts and kale are both members of the Brassica family of vegetables, which also includes broccoli, cauliflower, cabbage, and collard greens. This means that brussels sprouts and kale are closely related botanically and share many of the same characteristics.
Botanical Relationship
Botanically speaking, brussels sprouts and kale are both part of the Brassica oleracea species. This species encompasses multiple cultivars or varieties of the same plant species that have been bred to accentuate different parts of the plant.
Brussels sprouts are a cultivar that accentuates the lateral buds along the stem, resulting in the formation of the compact sprouts. Kale, on the other hand, accentuates the leaves, resulting in larger, ruffled leaves rather than sprouts.
Other cultivars of Brassica oleracea include broccoli, which accentuates the flowering heads, and cabbage, which accentuates the terminal bud to form a dense head. Despite appearing quite different, they are essentially variations of the same plant species.
Shared Characteristics
In addition to their botanical relationship, brussels sprouts and kale share many common characteristics:
- They have a similar taste profile – the flavor is earthy, bitter, and cabbage-like.
- They contain glucosinolates, which are sulfur-containing compounds that give them their pungent aroma and bitter flavor.
- They both have high levels of antioxidants like vitamin C, vitamin K, and polyphenols.
- They are nutrient dense foods, low in calories but high in fiber, vitamins, and minerals.
- They can be eaten raw or cooked and used in similar ways in recipes.
- They are cool weather crops that thrive in similar growing conditions.
Differences
While brussels sprouts and kale are closely related, there are some differences between them:
- Appearance – Brussels sprouts grow as miniature cabbages on a stem. Kale has ruffled or plain leaves growing on stems.
- Texture – Brussels sprouts are dense and compact. Kale leaves are more tender.
- Flavor – Kale is slightly more bitter than brussels sprouts.
- Uses – Brussels sprouts are often roasted or sautéed whole. Kale is more tender and traditionally eaten raw or quickly cooked.
- Cultivation – Brussels sprouts are trickier to grow than kale and have a longer growing period.
Nutrition Comparison
Despite some differences, kale and brussels sprouts have very similar nutritional profiles. Here is a direct comparison of the main nutrients found in 1 cup cooked brussels sprouts vs. 1 cup chopped raw kale:
| Nutrient | Brussels Sprouts | Kale |
|---|---|---|
| Calories | 56 | 33 |
| Protein | 4g | 2g |
| Fiber | 4g | 2g |
| Vitamin C | 97mg | 134mg |
| Vitamin K | 195mcg | 547mcg |
| Vitamin A | 831IU | 10,302IU |
| Iron | 1.4mg | 1.1mg |
| Calcium | 42mg | 150mg |
As you can see, brussels sprouts and kale are nutritionally very similar, with kale edging out brussels sprouts slightly in certain vitamins like A and C. But both are extremely nutritious foods packed with vitamins, minerals, antioxidants, and fiber.
Culinary Substitutes
Due to their similar flavors and textures when cooked, brussels sprouts and kale can often be used interchangeably in recipes. Some examples:
- Sauteed or roasted as a side dish
- Added to soups, stews, casseroles
- Pureed into a creamy soup
- Massaged raw into salads
- Baked into fritters or falafel
Keep in mind that kale leaves are more tender than the sprouts, so they may require slightly less cooking time. But their bitterness and earthiness lend themselves well as substitutes in most recipes.
Growing Conditions
Brussels sprouts and kale thrive under similar cool weather conditions. Some optimal growing guidelines include:
- Soil – fertile, well-draining soil with plenty of organic matter. Soil pH between 6.0-6.8 is best.
- Sunlight – full sun is ideal, at least 6 hours per day.
- Temperature – grows best in cool weather, ideal temps are 60-75°F during the day and around 40-50°F at night.
- Water – consistent moisture is important, about 1-1.5 inches per week.
- Fertilizer – compost and balanced fertilizer with nutrients like nitrogen, phosphorus, and potassium.
- Planting – sow seeds or plant starters in early spring or late summer/fall.
Kale is more forgiving and faster growing than brussels sprouts. But both thrive in similar environments and can be grown together in the garden.
Companion Planting
Brussels sprouts and kale grow well together as companion plants. Some other beneficial companion options include:
- Onions, garlic, chives – help deter pests.
- Beans, peas – fix nitrogen in soil.
- Marigolds – repel insects.
- Mint – deters cabbage worms.
- Lettuce, radish – can be interplanted between rows.
Incompatible plants to avoid include:
- Strawberries, tomatoes – can encourage blight.
- Pole beans – compete for sunlight.
- Peppers, eggplant – may stunt each other’s growth.
Interplanting brussels sprouts and kale together or with compatible companions can lead to a healthy and abundant harvest!
Pests and Diseases
Brussels sprouts and kale share many of the same pest and disease problems common among brassicas. Some issues to watch for include:
- Cabbage worms – use row covers, check under leaves, and apply Bacillus thuringiensis.
- Aphids – blast off with water or use insecticidal soap or neem oil.
- Cabbage loopers – pick off by hand or apply Bacillus thuringiensis.
- Clubroot – avoid planting in infected soil, rotate plantings.
- Alternaria leaf spot – improve air circulation and avoid wetting foliage.
- Black rot – discard infected plants, practice crop rotation.
Proper soil management, crop rotation, and maintenance of good garden sanitation practices can help prevent many of these common brassica pests and diseases.
Harvesting
Timing the harvest is important for achieving peak flavor and quality:
- Brussels Sprouts: Harvest from the bottom up when sprouts reach about 1-1.5 inches in diameter. Larger sprouts tend to get more bitter. The entire stalk can be cut for harvest.
- Kale: Individual leaves can be harvested any time. For whole plants, harvest after the first frost when flavor improves. Cut stems above lowest leaves.
Brussels sprouts hold well on the stalk for an extended harvest. Kale leaves are best used fresh but store for a few days refrigerated. Both can be frozen for longer storage.
Conclusion
In summary, brussels sprouts and kale are closely related as members of the Brassica oleracea species. They share many similarities in terms of flavor, nutrition, growing conditions, and uses in the kitchen. But there are also some slight differences in appearance, texture, and cultivation requirements. Their relatedness makes them ideal companion plants in the garden and suitable substitutes in recipes calling for either brassica. So consider planting kale and brussels sprouts side by side to take advantage of their botanical relationship!