Can You Eat a Potato With Blight? A Guide for Gardeners
As a gardener, finding blight on your potato plants is disheartening This fungal disease can quickly destroy foliage and spread to tubers. But what if some potatoes show only minor blight damage? Can you still eat them safely?
Blight comes in two main forms early blight and late blight The latter is more aggressive and can destroy entire crops within weeks Both types produce brown or black lesions on leaves that can spread through water droplets to soil and tubers. Potatoes with blight may exhibit surface discoloration, mushy spots, or a foul odor.
So can you eat a potato with blight damage? The answer is – it depends. Here’s what you need to know:
Potential Risks of Eating Blighted Potatoes
Consuming potatoes impacted by blight poses some health risks
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Toxins – The fungal lesions contain solanine, which can cause gastrointestinal distress.
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Bacteria – Decaying tubers may harbor E. coli and Salmonella, leading to food poisoning.
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Internal Damage – Even if the exterior seems fine, microscopic blight may lurk inside.
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Inadequate Cooking – Neither solanine nor bacteria are destroyed by cooking at typical temperatures.
So while a potato with minor early blight spots might be safe after heavy peeling and cooking, anything more extensive or any late blight damage is unsafe to eat. The toxins and bacteria can persist internally even if you remove external blemishes.
Signs a Potato is Too Far Gone
Watch for these red flags that indicate a blighted potato is too contaminated to consume:
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Large dark lesions covering over 25% of the surface – Soft, mushy consistency
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Visible fungal growth on lesions – Foul, musty odor
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Dark ring patterns inside when cut open – Shriveled, wrinkled skin
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White mold within potato flesh – Known late blight infection
Any of these signs mean do NOT eat the potato, even if some parts look healthy. Toss tubers with intense damage in the compost pile.
When In Doubt, Play It Safe
Unsure if a potato is heavily blighted or only mildly affected? Error on the side of caution:
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Discard any tubers from a late blight infected crop.
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Toss potatoes with over 25% surface discoloration.
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Do not eat potatoes with any internal dark spots or rot.
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If it smells funky or musty, compost it.
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Peel away eyes, sprouts, green skin, and lesions.
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Cook thoroughly until mushy to kill contaminants.
Don’t take risks with questionable potatoes. Better to be safe and avoid possible illness.
Safely Consuming Potatoes After Minor Blight
With early detection, potatoes with light blight damage can still be enjoyed:
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Inspect tubers closely, inside and out, before cooking.
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Peel away eyes, sprouts, green skin, and any discolored lesions.
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Dice and check again for dark streaks or soft spots. Remove those sections.
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Cook thoroughly until very soft and mushy.
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Don’t eat raw, like in salads. Always cook.
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Don’t freeze or can potatoes that had any blight damage.
With meticulous inspection, peeling, and cooking, potatoes with superficial early blight may still be safe to eat. But late blight or any internal issues means do not consume them.
Preventing Blight on Your Potato Crop
An ounce of prevention is truly worth a pound of cure with blight. Options for organic prevention include:
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Choosing blight-resistant potato varieties.
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Allowing ample space between plants for airflow.
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Watering at the soil line in the morning.
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Applying organic biofungicides.
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Avoiding overhead watering.
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Using thick organic mulch to suppress soil splash.
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Practicing crop rotation.
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Removing blighted plants immediately.
With diligent monitoring and preventative care, you may be able to avoid blight altogether and enjoy abundant, healthy potatoes.
The Bottom Line on Eating Blighted Potatoes
Exercise caution when deciding whether to eat potatoes showing blight damage. Inspect thoroughly, inside and out, for any red flags. When in doubt, do not consume tubers that may be contaminated. Remove eyes, skin, and lesions before cooking thoroughly. Enhance your blight prevention regime.
With prudence and proper handling, you may be able to safely eat potatoes from a blight-affected crop. But late stage blight or internal decay makes the risk not worth taking. When dealing with this sneaky foe, erring on the side of safety is wise. Your health is too important to chance.
Are tomatoes and potatoes with late blight safe for eating and canning?
Jeannie Nichols, – September 01, 2014
Late blight on tomatoes and potatoes is a devastating fungal disease that has surfaced in Michigan.
Late blight is affecting Michigan tomato and potato growers and home gardeners alike. The late blight has already been reported in Allegan, Clinton, Gratiot, Ingham, Ionia, Isabella, Macomb, Montcalm and St Joseph counties on USA blight. USA blight is a national website project on tomato and potato late blight in the United States. At this site you can report disease occurrences, submit a sample online, observe disease occurrence maps and sign up for text disease alerts. There are also useful links to a decision support system, and information about identification and management of the disease.
Late blight in both tomatoes and potatoes is caused by the oomycete Phytophthora infestans, and is a worldwide destructive disease.
Under favorable weather conditions, tomato and potato crops can be destroyed within days. Cool, moist conditions are considered most favorable for late blight to develop and spread. This blight is highly contagious to other plants in home gardens and commercial fields.
Do not can tomatoes with late blight. Tomatoes showing signs of late blight disease have firm, dark brown lesions that quickly become large, wrinkled and somewhat sunken. Diseases such as this may lower the acidity of the tomato flesh to a level that makes it unsafe for canning. Even tomatoes with the infected parts removed should not be canned. The United States Department of Agriculture Complete Guide to Home Canning recommends that only disease-free, preferably vine-ripened, firm tomatoes be used for canning.
According to Dr. Barbara Ingham, food safety specialist with the University of Wisconsin Extension, you can safety eat and preserve unblemished tomatoes growing on plants with leaves, stems or adjacent fruit showing signs of infection. However, these tomatoes are at a higher risk for developing the late blight lesions after they are harvested, so make sure to eat or process these tomatoes as soon as possible after harvesting them.
Michigan State University Extension always informs home canners of the importance of acidifying tomatoes. Adding bottled lemon juice or citric acid to your disease-free tomatoes raises the acidity level enough that Clostridium botulinum spores cannot survive, and produce a deadly toxin that causes botulism. Add two tablespoons of bottled lemon juice or a half-teaspoon of citric acid to each quart of tomatoes. For pints, use one tablespoon of bottle lemon juice or one-quarter teaspoon citric acid. Just add the lemon juice or citric acid before filling the jars with tomatoes or tomato juice.
It is also not recommended to eat fresh or frozen diseased tomatoes even if the diseased parts have been cut out. The disease organism by itself is not harmful but the tissue damage causes the tomatoes to have lower acidity and creates conditions that promote the growth of other potentially harmful microorganisms. The tomatoes may or may not have an off flavor.
The exact same advice is given for potatoes. Only use firm, disease free potatoes for eating, canning or freezing. Never use potatoes showing sign of late blight. Discard the whole potato rather than cutting off diseased parts in case it has spread to the inside of the potato. Potatoes are a low acid food and should be pressure canned.
Up to date recipes for canning can be found at the National Center for Food Preservation.
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FAQ
What happens if I eat a potato with blight?
Solanine Toxicity: Blighted potatoes can contain higher levels of solanine, a naturally occurring toxic compound found in green or damaged potatoes. Consuming solanine can lead to symptoms such as nausea, vomiting, diarrhea, headaches, and in severe cases, neurological issues.
When should potatoes not be eaten?
As they age, or with improper storage, potatoes may develop sprouting and green spots. If there isn’t any sprouting, you can use the color change as an indicator of spoilage. If the skin looks greenish or if there’s sprouting present, you’ll need to remove the sprouts or toss the whole potato, depending on severity.
What to do if your potatoes have blight?
Vigilance. If you notice blight on the leaves, cut the stems at ground level leaving the tubers in the ground for at least ten days before moving them.Aug 22, 2012
What does a potato with blight look like?
Affected tubers have a reddish-brown decay below the skin, firm at first but often soon developing into a soft rot as the blighted tissues are subsequently invaded by bacteria. Light attacks of blight may not be visible on the tubers, but many infected tubers will rot in store.
Can you eat potatoes if they have blight?
The exact same advice is given for potatoes. Only use firm, disease free potatoes for eating, canning or freezing. Never use potatoes showing sign of late blight. Discard the whole potato rather than cutting off diseased parts in case it has spread to the inside of the potato. Potatoes are a low acid food and should be pressure canned.
Is it safe to eat potatoes for gout?
Potatoes are safe foods for people with gout. However, attention and care must be taken when preparing the potatoes, as frying must be avoided.
Do early potatoes help prevent blight?
By sowing early potatoes, you’re more likely to escape blight infection, as you’ll harvest them before the weather gets warm and humid enough for the rampant spread of blight. For home gardeners dealing with temperate, damp weather conditions, late potato blight is almost a given.
Can blight rot potatoes?
Once you see your crop has been affected by blight, the best thing you can do is to use the tubers as soon as possible, as long as they don’t show obvious defects. Blemishes caused by early blight are more forgiving and tend to heal when cured, compared to late blight, which can rot your entire crop of potatoes if you’re not vigilant.
When should you harvest potatoes affected by blight?
If your crop of earlies has been affected by blight, here’s what you can do: Kill the potato vines two to three weeks before harvest time. Be careful not to injure the potato skins during harvest. Store tubers in conditions that promote skin healing – fresh air, temperatures between 55 and 60F – for 2 to 3 weeks.
How do I protect my potatoes from blight?
To protect your harvest from potato blight, you need to make sure your soil is healthy. One way to do this is with high-quality nitrogen and potassium fertilizer. You should also add mulch or compost near your plants to keep moisture levels high in the ground, making it harder for fungal spores to infect your potatoes.