Kristie Leong M.D. is a family practitioner who believes in the power of nutrition and a healthy lifestyle to prevent and fight illness.
Can You Eat Kale With Black Spots?
Kale is delicious, versatile, and one of the healthiest greens you can put on your plate. Kale is high in fiber, vitamin C, some B-vitamins, calcium, iron, and antioxidants, making it an excellent choice for a healthy diet.
But what if you have a stash of kale in the crisper with black spots on it? You might wonder whether you should eat it or toss it. Let's look at what causes black spots on kale, what they mean, and how they affect the flavor and safety of kale.
What Causes the Black Spots?
One of the most common reasons kale leaves develop black spots is they’re infected with a fungus called leaf spot. In this case, fungal spores land on the leaf surface and grow into small black spots that may contain golden haloes around them. The fungus will usually grow along the veins of the leaf until it covers the entire leaf surface with black spots.
The black spots come from decomposition of the plant related to breakdown by the fungus. Infection with bacteria can also cause a similar appearance. While kale leaves infected with a fungus or bacteria sounds ominous, it's not a problem for humans who eat the leaves. The fungus damages the leaves of the plant but creates no ill effects in humans.
Avoid Eating Rotten Kale
Fungi and bacteria that infect plants are distinct from those that cause illness in humans. Just as we can't infect plants with fungi and bacteria from your skin, plant fungi and bacteria do not cause illness in humans. However, you shouldn't eat kale that looks soggy or has a bad smell. Black spots on kale with otherwise healthy-looking leaves is safe to eat.
If you're buying pre-cut or pre-washed bagged salad mixes that are chopped and torn into pieces, the black spots could also be from bruising. Trauma can cause black darkened areas to form. Inspect pre-bagged kale and salad mixes carefully to avoid damaged leaves.
Should You Eat Kale With Black Spots?
Since kale with black spots isn't harmful to humans, it's okay to eat it. That bowl of kale won't look as pretty as unblemished kale but it's safe to eat. For the prettiest kale, look for bright green leaves that were recently harvested. Bright green leaves indicate the kale is likely to be fresher, crisper, and more flavorful than darker leaves.
Dark leaves indicate that the plant was stressed by heat, drought, or disease and this can impact flavor. Yet it could boost the antioxidant properties of kale leaves since plants produce chemicals that fight oxidative stress as protection during times of injury.
If you have questions about how much time passed between harvesting and selling when buying kale, ask questions! Buying kale from a local farmer's market is one way to find a fresh bunch.is in the late fall, winter, and early spring. Kale is a cool-weather crop, meaning it grows best during the winter months.
How to Choose Quality Kale
Beyond black spots, do you know how to choose quality kale? Kale should be a deep, rich green color throughout. If it has wilting or limp leaves or a yellowish or brownish tint, the kale was not harvested properly and may have lost nutrients through improper handling.
Wilting or limp leaves can also be an indication that kale is past its prime (which will cause it to turn yellow), so consider buying smaller bunches of kale instead of larger ones which could go bad quickly.
Also, be sure not to buy any vegetables with slime covering them. This means that they were exposed to too much water, which may have allowed fungi to grow on the leaves or stems.
How to Enjoy This Nutritious Leafy Green
Kale is one of the most versatile greens and you can enjoy it raw or cooked. Here are some of the many ways to enjoy kale:
- Raw in salads and on sandwiches and wraps
- In smoothies
- Sauteed with olive oil and garlic
- Steamed with olive oil and red pepper flakes
- Roasted with olive oil, salt, and pepper
- Raw kale chips made in an oven or dehydrator
- In soups
- On pizza
You can also use kale in any recipe where you would use spinach or another leafy green.
Choose the Best Tasting Kale
Can I eat kale with black spots? Yes, and kale should become a staple in your life if you're trying to eat healthier. But, for the best flavor, avoid kale with very dark leaves. Kale with black spots may taste significantly worse than fresh, green kale with no spots.
If you have kale with black spots at home and don't want to waste food, eat it—but don't count on it tasting as delicious. When you choose kale at the grocery store or farmer's market, avoid buying kale with black spots for the best taste. Now go treat yourself to a nice big bunch of dark green leaves—you deserve it!
- "Kale, raw nutrition facts and analysis.." https://www.nutritionvalue.org/Kale%2C_raw_nutritional_value.html.
- "Kale Study - Agricultural Research Service." https://www.ars.usda.gov/ARSUserFiles/80400510/Completed%20Studies%20Summaries/Kale%20Study.pdf.
- Keinath AP, Toporek SM, DuBose V, Zardus SH, Ballew JB. First Report of Alternaria japonica, a causal agent of black spot, on kale in South Carolina, United States. Plant Dis. 2021 Feb 22. doi: 10.1094/PDIS-01-21-0085-PDN. Epub ahead of print. PMID: 33616432.
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.