It’s heartbreaking to see your carefully tended zucchini plants bear squash that is misshapen and bumpy. But don’t throw those sweet zucchinis away just yet! Fruit that is misshapen on zucchini may not look appealing, but it’s usually still safe to eat if the problem isn’t caused by disease. Let’s look at what causes bumps on zucchini and if it’s safe to eat misshapen fruit from your 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 may split or bulge after they blossom because they swell up so quickly. Warm weather and abundant watering fuels rapid growth.
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Too much calcium in the soil can cause warty growths to appear 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 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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It grows quickly and is safe to eat as long as the skin is still on. 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 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 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:
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Select disease-resistant varieties specifically labeled as tolerant to common viruses.
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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 weed-free to prevent viral spread.
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Avoid over-fertilizing with nitrogen which fuels fast 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 disappointing. 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 summer squash variety 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.
Is it only the variety? Perhaps it’s meant to seem like that!
Take a fast look at the kind of zucchini you planted before you waste too much time troubleshooting!
- Different types of zucchini aren’t all bred to be perfectly smooth, uniform cylinders. Some older, heirloom varieties were picked for their taste, unique colors, or other traits; perfect shape wasn’t always the most important thing. These types might naturally make fruit with shapes that are a little less even, like “Ronde de Nice” fruit, which has interesting bumps, soft curves, or even round shapes. Don’t worry about it; it’s just a part of their history and personality!
- Look at the Description on the Seed Packet: Look at the description or plant tag on your seed packet or plant tag. Does it say anything about the right shape for the variety you’re growing? Maybe those bumps are on purpose.
The Prime Suspect: Incomplete or Poor Pollination
Usually, nine times out of ten, this is the main cause of strangely shaped zucchini. It all comes down to how these plants make babies, or fruits! Remember how zucchini plants have male flowers on long, thin stems and female flowers with the baby zucchini visible behind the petals? Pollen has to travel from the stamen of the male flower to the stigma of the female flower for the baby zucchini to grow into the full-sized fruit we want. Usually, bees take care of this delivery service.
How It Functions (or Doesn’t!): Imagine the inside of that female flower’s stigma as having several landing zones linked to little possible seeds (ovules) inside that baby zucchini (the ovary). Most of those landing zones need to get a good dusting of pollen to fertilize most of the ovules. This will let the fruit swell evenly all over and grow into that classic, smooth zucchini shape.
Patchy Work Results: What happens if a bee visits but doesn’t do a full job? Maybe there weren’t enough visits by bees, but it’s still possible. Should some areas of the stigma get pollen, then only some of the ovules become fertilized. The plant’s energy will cause the parts of the fruit that are connected to the fertilized ovules to start to grow and swell. The parts that are connected to the parts that haven’t been pollinated don’t get the growth signal, so they either fall behind or stop growing all together.
Common Shapes Emerging from This: This uneven growth causes directly those traditional misshapen shapes we frequently observe:
- Pinched Blossom End: The stem end got pollinated and began to grow, but the flower end (far end) didn’t get enough pollen, so it stays thin and underdeveloped.
- If you have a bulbous blossom end, the blossom end got a lot of pollen and grew big, but the stem end didn’t, so the fruit looks like a club or a bowling pin.
- Curved Fruit: One side of the fruit grows much faster than the other because of uneven pollination along the length of the ovary. This can make the zucchini grow in a big curve or bend.
- Generally Uneven, Bumpy, or Constricted: Sometimes, the pollination is just generally patchy, making the fruit’s growth uneven, bumpy, or constrained all the way along its length.
What Causes Pollination to Fail? Many things can disrupt the bees’ vital labor:
- Too Few Bees: This is a major issue. Could it have been rainy, cool, or windy all morning, when the flowers are open? That would have kept the bees inside. There may not be enough other flowers in your garden to attract and keep a good population of pollinators close by. A lot of pesticide use in an area can also greatly reduce the number of bees living there.
- Flower Timing Mismatch: The plant just can’t keep up with the times sometimes. It could produce a lot of male flowers before any female flowers show up, or it could produce female flowers after male flowers. Both the male and female flowers must be open at the same time for pollination to happen. Usually, each flower only lasts one morning.
- Interrupted Visit: A bee might land on a female flower but leave because of wind or noise before visiting all parts of the stigma. This is what causes the patchy pollination.
- To be a Bee Haven, put flowers that bees like near your squash, like borage, sunflowers, bee balm, and cosmos. It’s important not to use broad-spectrum pesticides, especially when your plants are flowering, because they can hurt or kill the pollinators you need.
- Try Hand-Pollination: Don’t undervalue your capacity to intervene; try hand-pollination. Our pollination guides explain that moving pollen gently with a male flower or a small brush first thing in the morning is the best way to make sure that all the flowers are pollinated and that the fruit grows well. It’s simple and really gratifying!.
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FAQ
Why does my zucchini have bumps on it?
The Cucumber Mosaic Virus, to be exact. The virus was passed from an aphid to a zucchini plant. It will then attack any other vegetable plant in this family and cause these ugly bumps. The good news, it won’t move from plant to plant or linger in your soil (whew!) but it will destroy your zucchini plant.
How to tell if a zucchini is unsafe to eat?
“Off” smell or taste: If your zucchini smells sour or foul in any way, or if it tastes unusually bitter, it has likely gone bad.
Is it okay to eat bumpy squash?
Yes, totally safe to eat. There’s an entire world of cross-breeding in order to get bumps, mostly on winter squash/ pumpkins. (Warty Goblin, Knucklehead, others. ) Different companies crookneck squash are different levels of bumpy. Territorial Seeds has some of the bumpiest ones I’ve seen.
Is it safe to eat zucchini with bite marks?
They are both totally safe! The zucchini scratches look more to me like scrapes from the prickly bits on the zucchini plant or got dropped or something. If they flip you out you can totally cut or peel the scratches off!.