Right about 3 years ago when I moved into my own house and started growing a few vegetables in the backyard, I remember planting cauliflower and the surprise of seeing it turn a vibrant shade of purple.
At first, I thought I just bought an exotic variety and that it was supposed to turn purple. However, upon looking up this matter in detail and asking a few of my fellow gardeners, I realized it was a symptom of something else entirely.
If your cauliflower has also unexpectedly started turning purple and is testing your gardening patience, don’t worry! Here are 5 possible causes for this colorful dilemma, along with quick tips on how to prevent it:
5 – Genetic Variability
Yes, I know I said the problem is much deeper than just purple pigmentation but there are still chances you might have planted an exotic cauliflower variety without realizing it. What if it was supposed to turn purple?
Quick Fix: If you believe you’ve planted the wrong cauliflower variety, just let it be and harvest it once it fully grows. You can plant another batch of your desired white cauliflowers when the next growing season comes around.
4 – Temperature Stress
Anthocyanin is the pigment responsible for giving cauliflower the concerning purple-ish hue. This pigment is released in cauliflowers as a stress response when overly cold environmental temperature combines with long periods of light exposure.
Quick Fix: Row covers are your best friend during cold snaps. They will protect your cauliflowers from turning purple, especially when temperatures fall below normal range. Also, consider choosing cauliflower varieties that are less susceptible to color change in cold conditions.
As I have mentioned before, row cover were a complete game-changer for my garden. Not only do I use it in my veggies but also in my flowers!
I use this one from Amazon — the Agfabric Frost Blanket. You just drape it over the plants, and it keeps everything snug. The best part? It takes less than 5 minutes to set up!
3 – Nutrient Imbalance
Certain nutrients like phosphorus that are responsible for color management in plants and vegetables can become oversaturated in the soil and cause issues.
Nutrient imbalances like these shouldn’t be taken lightly as they can affect your cauliflowers in much more adverse ways.
Quick Fix: Use a high-quality balanced fertilizer that can provide your cauliflower with a steady release of nutrients and help improve soil health. Organic matter like compost can also come in handy to further enhance soil composition.
2 – Reaching Maturity
Cauliflowers are confusing vegetables. Sometimes, they grow up milky white but can later turn a light shade of purple. Many speculate this color change is due to maturity and that it’s a common occurrence once cauliflowers grow big enough.
Frankly, there’s not much you can do in this case. Just harvest the purple cauliflower and enjoy I guess…?
1 – Excessive Light Exposure
Yes, you read that right! Too much light can certainly cause your cauliflowers to turn a purple-ish hue!
This is mostly due to the fact that long periods of light stimulate anthocyanin production which, as we discussed, is the pigment responsible for adding that purple hue to cauliflower.
Quick Fix: Protection is once again the only strategy that’s useful here. If you can’t control the light and how long your cauliflower is exposed to it, you can certainly reduce exposure by covering up the vegetable with a shade cloth.
Also, since you can’t really relocate cauliflowers while they are developing in the garden, consider planting your next batch in a partially shaded area.
Final Words
Seeing your milky white cauliflower turning purple out of nowhere can be perplexing, especially when it’s not supposed to do that.
However, whether the issues are caused by temperature fluctuations, nutrient imbalances, or neglect, understanding the causes deeper can help you take the right steps towards combating the color alteration and making sure it doesn’t repeat in the future.
