Q.Agapanthus losing too many leaves.
Every day or two I pull five or six dry brown leaves from the plant. Is this too many? How do I prevent this?
This could be due to environmental conditions, watering issues, lack of moisture, pests or disease.
It also could just be natural aging of the plant as the flowers mature and age.
Look for any signs of pests or disease on the leaves or flowers.
Treat with Neem Oil if you see pests.
Make sure the soil is moist, not soggy or too dry.
https://www.gardeningknowhow.com/ornamental/bulbs/agapanthus/diseases-agapanthus-plants.htm
https://www.gardeningknowhow.com/ornamental/bulbs/agapanthus/agapanthus-plant-care.htm