Squash come in a wide array of colors, sizes, and textures. There are very soft and very hard skinned varieties, with smooth, ridged, and warty shells. The most common and versatile squash are the zucchini and yellow summer squash varieties. Summer squash that is left on the vine for too long can turn yellow and bumpy, but there are other reasons why squash can get bumpy. Some diseases and pests can make normally smooth zucchini and other types of squash produce a squash that looks like it has warts on it.
It’s heartbreaking to nurture zucchini plants all season only to discover distorted, bumpy squash when harvest time arrives. But don’t toss those homely zucchinis into the compost yet! Deformed zucchini fruit may look unappetizing but is often still perfectly edible if the cause is not disease-related. Let’s explore what causes bumps on zucchinis and whether it’s safe to eat malformed fruit from the garden.
What Causes Bumpy Zucchinis?
Zucchinis with bumps, bulges, or scars on the skin are considered deformed There are a few potential causes of zucchini deformities
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Viral infection – Viruses like cucumber mosaic, papaya ringspot, watermelon mosaic, and more cause bumps on zucchini skin. These viruses cannot be cured.
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Fast growth – Zucchinis swelling very quickly after pollination may split or bulge. Warm weather and abundant watering fuels fast growth.
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Calcium imbalance – Too much calcium in soil can lead to warty outgrowths on zucchini skin.
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Insect/animal damage – Scarring from pest feeding or rubbing can deform zucchinis.
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Environmental factors – Temperature swings, drought stress, herbicide damage, etc. may deform fruit.
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Genetics – Some heirloom varieties naturally have bumpy skin.
Are Deformed Zucchinis Safe to Eat?
Whether or not consuming bumpy zucchinis poses any risks depends on the cause:
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Viral infection – Not safe to eat as viruses can make zucchinis toxic. Discard any virus-infected squash.
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Fast growth – Safe to eat as long as the skin is intact. The flavor is unaffected.
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Calcium imbalance – Safe to eat though may taste bitter. Monitor soil nutrients going forward.
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Insect/animal damage – Safe if damage is minimal and flesh is not rotten. Cut away any severely damaged parts.
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Environmental factors – Usually safe to eat unless extensive damage. Taste-test cooked flesh to be sure.
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Genetics – 100% safe to eat as bumps are natural to that variety. Flavor is great!
The key things to look for when determining if bumpy zucchinis are edible are:
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No signs of viral infection like leaf mottling or stunting.
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Fruit skin has no breaks or punctures that expose interior flesh.
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No mushy spots or damage extending into the flesh beyond skin deep.
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Interior flesh looks normal when cut into, not discolored or rotten.
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Cooked flesh tastes normal without bitterness or off-flavors.
As long as the bumps are superficial and the inside looks and tastes fine, enjoy using those quirky zucchinis!
How to Prevent Bumpy Zucchini Formation
While natural variation can cause some slight bumps, follow these tips to minimize major zucchini deformities in your garden:
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Select disease-resistant varieties specifically labeled as tolerant to common viruses like cucumber mosaic virus.
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Disinfect tools between plants to avoid spreading viruses.
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Control sucking insects that transmit viruses, like cucumber beetles. Use row covers.
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Practice crop rotation and keep the garden area weed-free to prevent viral spread.
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Avoid over-fertilizing with nitrogen which fuels rapid growth.
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Maintain even soil moisture, not excessive wetness. Use drip irrigation and mulch.
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Test soil nutrients and pH annually and amend soil as needed.
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Handle zucchinis gently when harvesting to prevent scraping.
What to Do With Bumpy Zucchini Plants
Finding bumps on your zucchini fruit is always a disappointment. Here are some options if your plant’s crop is extensively affected:
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Discard any zucchinis showing clear signs of viral infection. Remove and destroy the affected plants immediately to prevent spread.
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Bury or burn any questionable zucchinis. Never compost diseased plant material.
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Enjoy bumpy fruit caused by environmental factors or genetics. The flavor is fine! Use in baked goods, casseroles, etc.
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Consider planting a late crop of another type of summer squash in place of the zucchini if it is still early in the season.
While preventing zucchini issues is ideal, don’t let a few bumps totally discourage you. With smart growing practices, quick action if disease appears, and safely utilizing edible ugly fruit, you can still fulfill dreams of zucchini bread and grilled zucchini all season long. Just be vigilant about monitoring for problems and only eat what you know is safe.
Reasons for Bumpy Squash
Rapid growth, boring insects, and excess calcium in soil may contribute to lumpy squash plants. However, the majority of these fruit deformities are the result of a mosaic virus. There are many types of mosaic strains that occur in different fruit families. The cucumber mosaic virus is the variety that most commonly attacks the cucurbit family. There is also the watermelon mosaic, papaya ring spot, and zucchini yellow mosaic. Cucumber mosaic affects summer squash and produces raised, yellow bumpy squash and warty regions on the fruits skin. Watermelon mosaic affects both winter and summer squash. Summer squash get green overgrowths on the exterior, while winter squash grow knobby protrusions. Papaya ring spot produces malformations on the skin with color breaks over the surface. Zucchini yellow mosaic affects zucchini and results in distorted fruits and the squash is warty looking.
Why is My Squash Bumpy?
You are in the zucchini patch and see that the squash is warty looking and knotty. So, why is my squash bumpy? Squash are cucurbits, which are a type of fruit that includes pumpkins, cucumbers, and melons. Fruits in the cucurbit family are plagued by several different viruses, which can cause lumpy squash plants. The leaves usually don’t get any damage for a long time, but the fruits that are starting to form get knots and bumps on their skin. The texture of smooth skinned squashes is rough and patchy. The viruses that cause these symptoms can be found in the soil, and some of them are spread by insects.
How to solve some squash problems
Can you eat Bumpy zucchini?
In most cases, bumpy zucchini is still perfectly edible and can be used in the same way as smooth zucchini. However, it’s best to throw away the fruit if there are additional indications of deterioration or damage along with the bumps. What causes the bumps on my zucchini, and how can I get rid of them?
Can eating raw Zucchini cause pain?
Generally, it is not recommended to eat raw zucchini since it would be very hard for your body to digest. However, eating raw zucchini should cause pain, but it is possible that your body is having a hard time digesting it, giving you an upset stomach. Another possibility is that the large amount of fiber is causing you to have a lot of gas, which could be painful as well. Cooking zucchini is recommended because it will make it easier to digest and as a bonus it improves the flavor.
What causes bumps on zucchini?
Usually, bumps are considered a sign of one of the more serious zucchini problems, caused by one of many incurable plant viruses. Cucumber mosaic virus, watermelon mosaic virus, papaya ringspot virus, squash mosaic virus, and zucchini yellow mosaic virus can all cause these bumpy, deformed fruits.
Can yellow zucchini have bumps on its skin?
Yes, it is possible. Pick yellow zucchini before they get to that point to enjoy them at their best, because as they grow, they will get more spines. So it’s normal for your yellow zucchini to have bumps on its skin. Instead of waiting until the squash is old and “woody,” choose it while it is still young and soft.