The foliage on one of my Fennels (bulb) has turned slightly yellow and I am wondering what is causing this? Has anyone else experienced this problem? Could it be overwatering, or could the plant need a dose of Chicken Manure top dressing? I usually don't fertilize my herbs much, but am not sure about fennel. There is another plant growing next to it and the leaves are not yellow on it.
I appreciate your input, and thank you!