Cabbage is in the Brassicaceae family, and growing it in a home garden can be hard for a number of reasons, such as not making heads.
If you are new to growing this cruciferous vegetable, why not see our guide to growing cauliflower here.
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This article will talk about why white cauliflower heads can turn purple, how to keep that from happening, and what it means for quality and flavor.
Picture walking out to your vegetable garden, ready to harvest some fresh cauliflower for dinner. But when you peek under those outer leaves, instead of a pristine white head you find the curds tinged pink! While still edible, the color change can be alarming for gardeners expecting white cauliflower. Read on to learn all about what causes cauliflower to turn pink and how to prevent it.
What Causes Cauliflower to Turn Pink?
Cauliflower heads that develop a pink or purple hue are perfectly normal and safe to eat. The color change is caused by a pigment called anthocyanin that also gives red cabbage its vivid color. Anthocyanins form in the curds when the cauliflower plant is exposed to certain environmental stressors:
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Sunlight – Direct sun shining on the developing heads triggers anthocyanin production. The sun’s UV rays break down chlorophyll in the cells.
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Hot Temperatures – Heat speeds up the cauliflower’s growth and maturity, spurring a flush of anthocyanins.
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pH Imbalances – Soil that is too acidic can cause reddish pigments to form in cauliflower curds
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Genetics – Some cauliflower varieties have a genetic predisposition to develop pink curds even in ideal conditions.
While visually unappealing, the pink color is only skin deep and does not affect cauliflower flavor or nutrition. The key is protecting those curds from turning color in the first place.
Preventing Pink Cauliflower Heads
Here are some tips to keep your cauliflower pearly white from planting to harvest:
Choose Sun-Tolerant Varieties
Some cauliflower cultivars have more tolerance to sun exposure without reddening. Try ‘Snow Crown’, ‘White Sails’, or ‘Candid Charm’ for best sun resistance.
Plant Early or Late
Get transplants in the ground 3-4 weeks before your last spring frost date. This allows the heads to mature before the summer heat hits. Or do a late summer/fall crop for harvest after temperatures cool.
Use Floating Row Covers
Cover seedlings with floating row cover to create optimal microclimate conditions. The fabric lets in sunlight while deterring insect pests.
Provide Consistent Moisture
Cauliflower needs steady soil moisture, especially when forming curds. Water regularly so plants don’t experience drought stress.
Side-dress with Nitrogen
Give plants a nutritional boost by side-dressing with a nitrogen-rich fertilizer when heads begin developing. This fuels growth.
Blanch Cauliflower
When curds reach golf ball size, fold the outer leaves over the head and secure with a clothespin or rubber band to block sunlight. Check weekly.
Harvest on Time
Don’t leave mature heads in the garden too long. Harvest within 7-12 days of achieving 6-8 inch diameter. Overmaturity causes anthocyanins.
Check Soil pH
Test soil pH yearly. Cauliflower prefers a range of 6.5-7.0. Add lime if needed to prevent excess acidity.
With proactive steps taken at planting, during growth, and at harvest, you can sidestep pink cauliflower syndrome. A few simple cultural practices go a long way!
Is Pink Cauliflower Safe to Eat?
While visually startling, pink cauliflower is 100% safe and nutritious to eat! The pigments that cause the color change are antioxidants with no ill effects on humans. Here are some tips for enjoying your blushing bounty:
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Trim away any brown or oxidized portions on the curd surface before cooking. The pink interior flesh is fine.
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Cook as usual by roasting, sautéing, steaming or boiling. The color will fade to pale orange or cream.
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Pair with contrasting ingredients like bright green vegetables, white sauce or dark grains.
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Puree into soups or cauliflower rice for a bright pink color.
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Pickle cauliflower florets for a fun fuchsia ferment.
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Mix purple and white cauliflower together for a confetti-like medley.
The pink color is harmless, but you can intensify or dilute it for visual appeal. Cauliflower’s sweet, nutty flavor remains unchanged.
Common Questions About Pink Cauliflower
Here are answers to some frequently asked questions about cauliflower turning pink:
Is pink cauliflower GMO?
No, pink cauliflower is not genetically modified. The anthocyanin pigments occur naturally from environmental stressors.
Can you reverse pink cauliflower?
Unfortunately no, once those pigments develop the pink color is there to stay. It’s best to prevent it by protecting curds.
Does cauliflower turn pink when cooked?
No, cooking usually fades or removes the pink hues due to heat breakdown of the anthocyanins. Color change happens before cooking.
Can frost cause cauliflower to turn purple?
Yes, early frosts while heads are still maturing can instigate anthocyanin development resulting in purple curds.
Don’t dismay over pink cauliflower! With the insights above, you can reap perfect heads. Take preventive measures and get ready to enjoy nature’s colorful variety.
What’s Wrong with a Little Purple?
There are many cauliflower varieties from which to choose, so read seed packets and catalog descriptions carefully.
Some white ones, such as ‘Snow Crown,’ are known to blush pink in the summertime. This is not an anomaly, and it does not degrade the flavor of the curds.
And as mentioned, there are true purple cultivars as well, like the heading ‘Graffiti,’ and sprouting ‘Rambo Purple.’
The vivid pigment is the result of a gene mutation and an abundance of the flavonoid anthocyanin.
Not only that, but you might have let a hybrid plant go to seed, saved the seed, and then planted it.
As you may recall, seeds from hybrids do not produce “true. There will not be a copy of the hybrid plant from which the seeds were taken.
Instead, you’ll get traits that are hard to predict and may be similar to those of one or more of the parent plants that were crossed-bred.
Cross-pollination could be the reason you got heirloom cauliflower seeds from plants that were growing next to each other in the garden at the same time.
And finally, if you’re not growing a white variety that is known to have some color, a purple cultivar, hybrid seed, or an heirloom grown with other varieties, you should think that the unusual color is caused by the weather.
Brassicas, like cauliflower and broccoli, prefer cool temperatures. If you are trying to get a crop to maturity and the weather goes back and forth between cold and hot or there is a heatwave, the curds may not do well.
The expert horticulturists at the University of Minnesota Extension say, “Long days and hot weather in the summer cause… cauliflower curds to develop a red-purple discoloration and leaves through the center of the head.”
Can it be avoided? Let’s find out.
Cauliflower, White as Snow
When I was a child, cauliflower was strictly a white vegetable.
That’s how you knew it wasn’t broccoli!
Today, there are orange, green, and purple varieties, in addition to the snowy white curds filling grocers’ shelves.
But sometimes, developing white heads begin to look a little pink or purple. It may be around the edges, across the tops of the florets, or on their stems.
In business, this is one reason to lower the quality of a crop, and you might never see the fruits of this harvest in a major grocery store.
Let’s find out what it means for the home gardener.