Assuming you have not run into any pests/insects, I would monitor the soil moisture and make sure that the plant is not getting too much sun (a common problem of japonicas this time of the year). Browning from edges inwards typically hints at the need for more water.

When I looked at the pics, the top mulch looks dry (but I can't tell how it feels underneath). The normal amounts of water usually have to be increased here when Summer arrives so make sure you have increased yours too. Water deeply, not often. Example: newly planted shrubs get 1 gallon of water per watering in Spring and 1.5g in the Summer. I then switch back to 1g in the Fall/Winter (if it rains about 1", you can skip watering). If your soil is sandy, increase the amt of water by 50%.

To monitor the soil for soil moisture problems, use the finger method daily in the mornings for 2-3 weeks. Insert a finger into the soil to a depth of 4" and see if the soil feels wet, moist, almost dry or dry. Then water if the soil is almost dry or dry.

Every time you water, make a note on a wall calendar to indicate that you watered on that day and, after 2-3 weeks, see about how often you were watering? Every 2 days? Every 3 days? etc. With this information, set the sprinkler or drip irrigation to water 1.5 gallons of water in the Summer every 2/3/etc days. If temps change 10-15 degrees and stay there, re-use the finger method again to see if you need to tweak things.

Luis

Where do you live? Are the plants getting sun?

One of my camellias has the same issue as your photo number 1. Have you found an answer as to what’s causing it? Looks like the chlorophyll is being eaten away.

It may be time to look for pests gay.night time if it looks like something is nibbling to remove juices.

That makes sense given the scalloping bite marks. Better pests than some systemic disease. Thanks for the response.