Hello. My cauliflower was growing well and then one of the plants started to get gray discoloration at the tips of the older leaves. This rapidly spread throughout the leaf and the leaf becomes grey and crumbly and dry. The veins are largely unaffected. This has only happened in the outer, older leaves thus far.

I have looked for insects and have not seen any. The plants are on my rooftop in a container. The other cauliflower and broccoli plants in this container are growing well without signs of disease.

I was thinking this is a nutritional issue, but I'm not sure. I did add garden lime to my potting mix when I planted it. Thank you!

Hi Francisco What you describe could be powdery mildew, which often appears as a gray or white powdery coating on the leaves. If it is a more serious infection, the leaf may even turn brown.

Mildew often gets started when warm days are followed by cool nights and there is condensation on the plant.. Remove infected leaves for good sanitation and try to improve air circulation around the plants.

For future gardening, avoid the lime. It is not needed