Hydrangea diseases I believe my hydrageas have ...

Hi,

Some of the most common pests can be controlled without much cost and effort, really. Aphids suck the sap from the leaves which causes them to turn yellow. and sometimes brown. In bright sunlight the leaves will wilt or curl; this will cause a stunt in the growth. Aphids have pear-shaped bodies and are about the size of a tip of a pencil. They will be on the under side of the leaves. You can spray them away with a fine mist from your garden hose.
If you notice leaves turning brown and some seemingly threaded together and curling; this may be from leaftiers. The leaftier larvae tie leaves together for protection while they are feeding. You may notice 1/2 inch green caterpillars with brown heads. Remove them and drop them in a bucket of soapy water. Crush the larvae in the curled leaves and spray the leaves every couple of days until they are all gone.

Hi mac,

If you see leaves turning brown on their edges or leaves looking burned, this is probably from spider mites. These mites are tiny and too small to see with an unassisted eye. You might have better luck with a magnifying glass. You can spray leaves down every day for three or four days. Try to do this in the morning to not promote sun scalding. For heavier infestations use a light solution of insecticidal soap.
Some hydrangeas have blooms that change color widely thru the season. My macs tend to go from pink to green to brown. But brown is something I usually see by the Fall, not this early.
For that reason, I am going to suggest that you consider that the hydrangeas are getting too little water and/or too much sun.
Be aware that newly planted hydrangeas will require more water than established ones so be ready to water more than once a week during the summer.