Most of my cucumber and melon plants have these (cream) white spots of various size.
The white spots grow and some of the older leaves have withered (partly).
All plants come from seed, and have been planted in potting soil. Only common denominator for them all is the water, fertilizer (general fertilizer for "all flowering plants") and location.
Edit based on comment : location is indoor. Started seeds under grow lights in february. They are now behind a south facing window. Temperature is about 19 - 20C. Can't see anything "unwanted" under the leaves. New leaves start out fine, but seems to become "affected" over time.
What can I do to stop this?
- I've tried to spray the leaves with a mix of water and baking soda. Not successful / makes no difference.
- I've removed old leaves, but I obviously can't remove all the leaves.