Itea virginica Henry's Garnet with leaves turn brown and have rust spots
I planted three Itea virginica Henry's Garnet in the ground only two weeks ago. The plants were quite healthy when I bought them. With recent down pouring in the area, It has plenty of water; for the sunny days, I watered them once a day. The soil is quite alkaline; please see the attached picture of the pH soil test; the color is in the range of pH level of 8.0. When mulching, I have ensured that there is a well around the root.
This morning I noticed the leaves (of one plant) has brown ridges, and some have rust spots. Please see attached pictures. Please advice what I can do.
Itea is virtually disease-free, so we think the problems are primarily culture/environmental related.
As you know, this is an acid-loving plant. Try to bring down the pH. Here is a webpage about lowering pH for blueberries which should be helpful for you: https://extension.umd.edu/hgic/plants/blueberries-selection-and-planting
Also, though itea love moist soil, soil needn't be any wetter than a wrung-out sponge. Daily watering won't be necessary. Never water overhead, always direct the hose at the base of the plant or soil.