Sunburned Pond Plants
Some plants grow well in full sun, while the same plant may grow better in part sun in a different region. Sometimes it depends on the plant maturity. Younger plants are more vulnerable to plant burn than a mature pond plants. Water Lotus, for example, grows better in part sun when it is a seedling. Plants with dark colored leaves oftentimes get sun burned, such as this Australia Water Canna. After I moved mine into part sun, it grew great and even produced flowers.
Shade Cloth: Another option for hot dry climates is to hang a nursery shade cloth over the pond. The ones sold at the hardware store are 75% shade, which is too shady. Shade cloth for plants should be 30%-40% shade and can be purchased online. Not only will it protect your plants from sunburn, but it will protect your fish from predatory birds and will help reduce algae growth as well.
So if your pond plants
are starting to look brown and shabby, try moving them into a more
sheltered part of your garden or hang a shade cloth overhead. It might be all you need.