Late-Summer Tree and Shrub Care: Signs to Watch For

By late August, months of heat, humidity, and whatever insects or diseases have been building up all season tend to show themselves clearly on trees and shrubs. A few extra minutes walking the property this time of year can catch problems while they're still manageable.

Leaf Discoloration and Early Drop

Yellowing, browning, or spotted leaves — especially if a tree or shrub is dropping leaves noticeably earlier than its neighbors — is often a sign of fungal disease, insect stress, or root problems that built up over the growing season. It's easy to write off as "just late summer," but a healthy plant of the same species nearby usually gives a useful comparison.

Bark and Trunk Damage Add Up Over a Season

Cracks, cankers, oozing sap, or areas where bark has come loose are worth a closer look, since damage that seemed minor in spring can develop into a real structural or health issue by the end of summer. Trunk damage near the base is particularly worth catching early, since it's often where rot and pest entry points start.

This Is Also When Insect Damage Peaks

A lot of common landscape pests — bagworms, spider mites, various borers — do the most visible damage to foliage by late summer after a full season of feeding. Catching an infestation now, rather than waiting for it to show up again next spring, gives treatment a real chance to work before the plant goes into winter already stressed.

The Bottom Line

Late summer is when a season's worth of stress on trees and shrubs becomes visible — catching it now, rather than in spring, gives the best chance of treating a problem before it gets worse.