Photinia – Leaf Spot
Q: I have a row of red tips between me and my neighbor. I notice that the bushes at one end are losing leaves. The leaves also have dark circular spots on them. I do not know how to save them but I am sure whatever it is, the disease will spread.
A: The key to raising healthy red tip photinias is to grow them in full sunshine and to never prune them. The fungus that causes the leaf spot loves young red leaves. If you prune your photinias every spring, the new leaves are very susceptible to fungal infection. Even so, I commonly see large, unpruned photinias that have no spots at all.
If you must prune your photinia, do so in mid-summer. Use only hand pruners or a lopper to remove big limbs, never shear the shrub. In this way you’ll avoid a flush of new growth. You can use fungicide sprays (Fung-Away, Immunox, etc) for a couple of years to arrest the spread of disease but try my pruning suggestions for long term success with these shrubs.
see Photinia Pruning