What is plaguing my camellia?

Question: Hello, my camellia is not very happy. It's growth has been stunted since late summer. I notice that many of leaves appear to be "eaten" down to almost nothing. Others appear to have a white ashy scars along the edges of leaves, almost as if they've been burned by a match. (See photos attached.) I have tried to spot insects or caterpillars early in the morning, but so far haven't seen any. Have you seen this disorder before? Any help is much appreciated.

responder: Best Regards,   Replied April 25, 2023, 12:35 PM EDT
response: Hello, and thank you for contacting Ask Extension about your camellia. It's difficult to diagnose a plant problem from a single photo. When you say that many leaves are affected, can you estimate this as a percentage of the entire foliage?  Inspect the bark and twigs for any signs of damage.  Can you please send a photo of the entire tree and indicate where the damage occurs (top, bottom, cardinal direction, oldest or newest leaves, etc. ...)?  Meanwhile, watch the plant closely at this time of year for the presence of any larvae or new damage. We'll be happy to try to advise you with some additional information.

responder: The Question Asker Replied April 26, 2023, 10:05 PM EDT
response: Hi Lynne,Thanks for your help! I'm attaching some additional photos that are hopefully more informative. Leaves affected as a percentage: I'd say about half.The damaged leaves do appear to be worse higher up the plant, and perhaps more on the east-facing side. But I do notice some with the "burnt edges" pretty low on the bush as well.I have not yet been able to detect any pests, including larvae. We do have a lot of deer in our area seasonally, but I haven't seen any around in a while.On Tue, Apr 25, 2023 at 9:35 AM Ask Extension <<personal data hidden>> wrote:

responder: Best Regards,   Replied April 28, 2023, 12:03 PM EDT
response: Hello again,  Thank you for the additional photos. Your camellia certainly does not appear to be a happy plant, but I do not think the lack of vigor in the winter should be a concern.  Some of the leaf damage is most likely caused by an animal rather than insects. Deer, squirrels, and voles all enjoy a meal of camellia. However, the damage from late summer is probably environmental: excessive sunlight, heat, and/or insufficient soil moisture. Young plants are especially susceptible to these factors, and scorched leaves will break or fall off as a result.  I suggest a couple of actions: First, pull the straw mulch away from the plant as it can encourage rodent damage. If possible, use coarse wood chips instead, but do not let them touch the trunk.   Prune your plant now to encourage strong new growth. Remove any thin, weak stems, and cut back the longest stems to an outward-facing bud. In summer, thin out the bushy new growth from the center of the plant to allow light and air into the plant, keeping the stronger new stems. The leaves look somewhat chlorotic (yellow between the veins). This is often caused by over-watering or poor drainage. It can also be caused by soil pH being too high, but this is less likely in our area unless the native soil was replaced by more alkaline soil and amendments. You can apply iron chelate (use as directed on the label), or use Douglas fir mulch which is usually sold for blueberries.  Make sure you water your plant deeply if needed, but do not water unless the soil is dry at a depth of 2-inches. You can use a finger pressed into the soil: if it comes out dry, the plant needs water. If the soil sticks to your finger, do not water.  Stressed plants should never be fertilized, but it would be helpful to add up to an inch of finished compost to the top of the soil (but under the mulch) in a wide area around the plant. This should be done once or twice a year.   After taking these steps, watch for new growth now that the temperatures are warming. I would expect heavily damaged leaves to drop off and be replaced by fresh foliage.   I hope this information is helpful. Please write again if you have additional questions.