Carrots With Black Spots? 4 Reasons and What To Do
Carrots with black spots are gross, no doubt. You’ve probably seen it before. But I am sure you are wondering if those carrots are safe to eat and still tasty right? Here’s what I’ve found by experience.
Carrots may display black spots due to either pests or fungus. In particular, carrot rust flies, carrot weevils, carrot black rot, and mold are the most common reasons. Pests leave dark burrowing into carrots to feed, while black rot involves black scarring due to fungal disease. Lastly, mold growth can occur on carrots, leaving black patches.
Whether you’ve grown them yourself or simply bought them from the grocery, it’s disheartening to see your carrots covered with black spots. But these marks can be identified and even prevented, so keep on reading to learn exactly that and more!
Can You Eat Carrots With Black Spots?
Carrots with black spots can only be consumed if discoloration appears to be superficial. However, if scarring runs deep and if there are any signs of spoilage present, it is highly recommended to discard the carrot.
You may want to save money and eat these carrots anyway, but keep in mind that at best, its taste and texture may be compromised. At worst, this could be a health hazard. If damage is surface-level, the carrot can be eaten, but for safety purposes, I recommend this be boiled and put in soups.
Moldy carrots can be salvaged only if the mold is found on the surface, but if the damage is deep and the root has gone soft and slimy, toss that rotten carrot out. Remember, an ounce of prevention is better than a pound of cure.
4 Reasons Why Your Carrots Have Black Spots
After trying to give the black spots on your carrot a wash and seeing they don’t rinse out, you’re probably confused as to what the heck these things are. With numerous explanations floating about, I’ve helped make it simpler for you by collecting the different reasons behind this in one article.
1. Carrot Rust Flies
On average, black spots created by carrot rust flies are often typified by dark rust-colored tunnels found in the lower two-thirds of carrots. Tunnels may even contain headless cream-colored maggots, approximately 1 cm long, that have been feeding upon the root.
Carrot rust flies are a nuisance to gardeners everywhere. The primary destroyers are not the flies, but rather their larvae. Once adult rust flies plant eggs on your crops, the eggs hatch and the rust fly larvae will dig into the soil to feed on carrot roots.
You can tell the black mark is left by rust flies by the dark scars that stripe around the root. Mushy tunnels of a brown rusty color can be found on the lower two-thirds of the carrot, and may even be inhabited by the flies’ creamy headless maggots about 1 cm long.
2. Carrot Weevils
Black spots left by carrot weevils are frequently found on the upper one-third of carrots. Unlike rust flies, the appearance of adult weevils are similar to beetles, and they do not fly. Their larvae are white with brown heads and often C-shaped.
The damage done by carrot weevils can sometimes be tricky to identify, as oftentimes it appears almost identical to that of carrot rust flies. Both of these pests produce larvae that feed off of roots, but there are key differences that can be found.
Carrot weevils leave black spots as well, but the dark tunnels of weevils tend to occur on the upper one-third of the carrot rather than the lower section that rust flies frequently attack. Adult carrot weevils also look more like beetles rather than flying insects, and they do not fly.
Another way you can tell if the black markings are due to carrot weevils is by their larvae. The whitish grub of carrot weevils are C-shaped and come with brown heads, unlike the headless larva of rust flies. Usually, we don’t enjoy finding larvae in our vegetables, but in this case, inspecting your carrot for larvae will help you identify the source of the black scars.
3. Carrot Black Rot
Carrot black rot often appears as black spots as a result of the pathogen named Alternaria radicina. Grayish-black lesions can be found, but should not include any burrowing. Additionally, carrots damaged by black rot frequently display symptoms after harvesting, once they are in storage.
Black rot in carrots may almost look as if it’s been burned or tainted with ink. This is because once infected by black rot, the tissues blacken, typically at the crown of the root before making its way down the infected carrot. Gray-blackish depressions can be seen spread across the root, but they should only be sunken in and not include any tunnels.
Typically caused by the fungal disease named Alternaria radicina, carrot black rot can be both seed and soil-borne. Black rot tends to make an appearance during storage, after roots are harvested.
Mold can grow into black, hairy spots on carrots, especially if contained in high moisture. Carrots bearing black spots of mold may also be a signal the root has rotted and spoiled, hence leading to the growth of mold.
Although unpleasant, properly handling and preventing mold is much easier compared to controlling carrot rust flies and black rot.
You can tell if the black spots on your carrots are due to mold when you can clearly see the eruption of spores on the surface of the carrot. Mold thrives in high moisture, so if you keep your carrots in plastic, it’s very likely the roots will begin sweating, encouraging mold growth.
Carrots that are moldy may also indicate it has already spoiled and may have a sour odor, but it is not recommended to sniff these carrots. The mold can cause trouble for your respiratory systems, so keep that sniffer away!
Can You Remove the Carrot Black Spots?
It is not only possible to remove black spots from carrots, it is urged to do so. Any lesions or markings seen must be removed, and the carrot washed before consumption. If moldy, cut at least 1 inch (2.54 cm) away from the mold and, for safety precautions, ensure the knife does not come in contact with it.
The black spots on your carrots can not only be removed, but it’s highly recommended to do so. Even if you decide not to eat it, cutting the carrot open can be great to help identify the source of the black marks.
If the black spots are only superficial, you can carefully remove it and wash the carrot thoroughly. For mold, cut one inch outside the mold and take extra care the knife does not touch it and cross-contaminate the rest of the root.
Consider the type of carrot this is, as well. If these are whole, unpeeled carrots, these may be safer to eat, and you should have an easier time removing the black spots. However, if you’ve purchased a bag of peeled and trimmed baby carrots, any damage found on these are much more significant, and will be harder to cut into due to their small size.
Are Black Spots “Contagious” Among Carrots in the Same Bag?
If black spots on carrots are due to mold, spores will quickly disperse to other produce nearby. Unless infested with larvae, carrots impacted by pests are not likely to spread black marks to other roots. However, carrots infected by black rot may spread to other carrots.
If your carrots are moldy, there’s a pretty high chance that mold will spread to other carrots nearby. Anything near food that has gone moldy should be checked and moved immediately.
Carrots attacked by weevils and rust flies aren’t necessarily contagious, unless the larvae are still inside. In this case, the larva may continue feeding off of your other carrots nearby and create more unpleasant black markings.
The fungi in black rot can infect other root tissue, whether they are wounded or non-wounded. Infection is much slower if the tissue isn’t wounded, but the infection may still take place. Be sure your carrots are not bruised or cut open, and are generally not left next to other carrots showing black spots.
How to Prevent Black Spots in Carrots
It’s unfortunate to find a carrot with such scarring, but you’ve now identified all the different reasons a carrot may display them. Good job! To prevent this from happening again, let’s go over the many ways to counteract these black spots when growing carrots.
1. Carrot Rust Flies
For ideal protection, carrots must be grown in raised beds or containers and shielded with row covers to prevent low-flying rust flies from infiltrating. Additionally, strongly scented onions can be planted next to carrots, and insecticides containing Neem can be beneficial to repel rust flies.
Despite being only about 6 mm long, the damage caused by carrot rust flies can be significant and impact entire fields of crop if left unprotected. Luckily, though, there are many ways to prevent these pests from invading your roots.
To start, remove any infested carrots from your garden and harvest all the roots immediately to prevent the larvae from spreading. Monitor their presence by leaving yellow sticky traps at a 45º angle by soil level near carrots or by the ends of fields where adult rust flies exit. You can identify them by their reddish heads and pale yellow legs, with a hunchback-like thorax.
Besides being weak, carrot rust flies don’t fly too high. Many find it effective to grow their carrots in raised and narrow beds or containers with row covers placed over them to prevent rust flies from even landing on crops to lay eggs. You may also grow strongly scented onions and leeks next to your carrots, and use insecticides containing Neem to fight off carrot flies.
>>> Check our article here on How to Use Neem Oil On Plants.
2. Carrot Weevils
Due to carrot weevils overwintering in plant debris, all debris and mulch must be removed, and yearly crop rotations utilized to prevent weevil infestations. About 6 mm in length, they appear similarly to beetles. Sprays containing Neem oil can be used to ward off weevils.
These bugs technically do have wings, but rarely use them to fly, so luckily their invasions are not quite as great as rust flies. You can identify those measly carrot weevils by their dark beetle-like appearance, about 6 mm in length.
Carrot weevils usually overwinter in leftover plant debris, so remove any debris you find, including mulch. Umbelliferous crops (Carrots, parsley, celery, etc.) should be rotated and planted in different areas every year to cut down larvae survival rates.
You can stay alert by setting traps of carrot slices by the soil to watch any activities of carrot weevils, or alternatively, you can use Neem oil sprays to help combat these pests.
3. Carrot Black Rot
To prevent carrot black rot, seeds must be placed in hot waters of 122”°F (50 °C) for 30 minutes or be verified to be free of pathogen. Both seed and soil-borne, avoid using soils infected with black rot and ensure carrots are stored in cooler areas to prevent decay post-harvest.
Black Root Rot can sound frightening, but there are ways to combat this fungal disease and prevent it from leaving black marks on your carrots.
Since this pathogen can be both seed and soil-borne, it’s highly recommended to only plant seeds that are pathogen-free. If you’re unsure, treat seeds in hot waters of 122”°F (50 °C) for about 30 minutes.
As for soil, try to avoid using any known to have black rot, as the fungus can live up to 8 years underground. Consider using irrigation systems as well, as infections occur more often in wet soils, so be wary of heavy rainfall. Risk is more likely to go up post-harvest if carrots are stored in warm and humid areas, so try to maintain a cooler temperature for storage.
Mold thrives in high moisture and is more likely to leave black spots on carrots kept in wet soils or damp plastic bags. Ensure the root has the least amount of moisture possible by using well-drained soil, storing them without plastic bags, and not washing them until needed to prevent mold growth.
Mold loves environments that are high in moisture, so take care not to keep your carrots in wet soils for long periods of time. This can lead to black spots and mold underground. Make sure the soil for your carrots is well-drained and try not to over-water this plant.
In storage, it’s helpful to avoid keeping your carrots in sealed-off plastic bags. They might be convenient, but moisture is much more likely to stay inside these bags with your carrots, so leave them out un-bagged or make sure the plastic has holes to prevent condensation. Don’t wash your carrots until needed.
If the black spots on your carrots are due to mold after being stored in the fridge, it may be best to examine your refrigerator. Spores can build up inside your fridge and spread to nearby produce, so it’s important to maintain cleanliness to prevent mold growth.
Should You Eat Carrots With Black Spots Raw or Cooked?
For safety measures, it is highly recommended that carrots found with black spots be eaten cooked or boiled. Whether the carrots have been invaded by pests or salvaged from rot, it is not advised to eat these discolored vegetables raw.
If the discoloration is not deep, you may choose to eat it raw. But as delicious as fresh carrot sticks are, it’s probably best to eat these marked carrots cooked.
Even if the black markings can be removed, would you really want to eat a carrot burrowed into by insects and plagued with fungal disease raw and uncooked? I personally don’t.
For your health, it’s best to wash the roots thoroughly after removing the black spots and eat these carrots cooked and boiled.
Are Carrots With Black Spots Old?
Older carrots are more susceptible to form black spots, especially if kept in poor storage. As they decompose, the exposed root is more likely to contract mold and possibly become infected by carrot black rot, hence leading to black spots.
As carrots grow older and begin to decay, it’s not uncommon for them to grow black spots due to poor storage. They are especially vulnerable to black root rot as well, one of the items we covered earlier.
However, black spots created by carrot rust flies and weevils happen regardless of the age of the carrot, as the larvae will simply feed off of whatever root they encounter in the soil.
Summary of Black Spots in Carrots
The black spots found on carrots can be a result of multiple different factors. Some of these factors would include: carrot rust flies, carrot weevils, carrot black rot, and mold.
Both the rust fly and weevil leave dark spots when their larvae burrow into the root to feed, while black rot involves blackish scarring across carrots due to a fungal disease. Lastly, if kept in overly damp environments, mold can be the source of black spots on carrots.
- “Carrot Insects” by AB Stevenson in Ontario Ministry of Agriculture, Food and Rural Affairs
- “Carrot (Daucus carota)-Black Rot” by n/a in Pacific Northwest Extension Pest Management Handbooks
- “Molds on Food: Are They Dangerous?” by n/a in Food Safety and Inspection Service, U.S. Department of Agriculture