August 9, 2025

Mahoney’s Garden Centers Shares Expert Guidance on Cicada-Related Tree Damage

FOR IMMEDIATE RELEASE
August 2025

Expert Insights from Veteran Horticulturalist David Carpinella on Protecting Young Trees

Osterville, MA – Following the mid-summer emergence of 17-year periodical cicadas, many oaks and maples along Route 28 have displayed stressed and dying branch tips—a visible reminder of the damage these insects can inflict. According to David Carpinella, veteran horticulturalist and general manager of Mahoney’s Garden Center in Osterville, the injury stems from female cicadas cutting slits in young branches to lay their eggs.

“Established trees can withstand even a large infestation,” Carpinella explained. “The real concern is for younger trees and shrubs. Their new growth is more vulnerable to the slicing, their root systems are shallower, and the newly hatched nymphs can attach themselves to surface roots, adding further stress.”

In addition to physical damage, the branch splits can serve as entry points for disease and fungal infections, compounding the problem for vulnerable plants.

 

Preventive and Post-Emergence Care Tips

• Prompt pruning: If branch slits are detected early, prune and dispose of affected limbs before nymphs descend to the roots.
• Care for younger trees: Avoid removing more than half of the canopy; excessive pruning can impair photosynthesis and reduce recovery chances.
• Ongoing monitoring: Watch plant health closely during hot summer months, as damaged trees are more prone to stress.
• Supportive feeding and watering: Provide additional water and nutrients. Carpinella recommends an organic emulsified fish fertilizer such as Neptune’s Harvest Fish and Seaweed, applied once every seven days, to help replace lost nutrients.

Carpinella emphasizes that while the most recent cicada emergence peaked in early to mid-July, understanding the signs and responses now will help property owners protect trees during future cycles.

 

 

About Mahoney’s Garden Centers
Mahoney’s Garden Centers is a family-owned business with seven locations across Massachusetts, offering expert horticultural advice, high-quality plants, and gardening supplies. The Osterville location serves Cape Cod gardeners with a curated selection of plants and a knowledgeable team.

FAQ: Cicada Damage on Trees (Cape Cod & Massachusetts)

Cicada damage can look alarming, especially when entire branch tips start to brown and die back. This FAQ addresses the most common questions homeowners have about identifying, managing, and preventing injury from periodical cicadas, with a focus on protecting young trees and shrubs.

What causes the browning at branch tips on oaks and maples?

Female periodical cicadas cut slits into young twigs to lay eggs. Those twigs often “flag” (brown and die back) at the tips.

Are mature trees at risk of dying from this?

Generally no. Established trees usually recover on their own, even after heavy emergence years.

Which plants are most vulnerable?

Young trees and small ornamental shrubs. Their new growth is easily damaged, roots are shallower, and newly hatched nymphs can attach to surface roots.

What should I do if the slits are fresh?

Prune and discard affected twigs before nymphs descend to the roots. Dispose of prunings off-site.

How much can I prune?

Avoid removing more than half of the canopy on young plants. Excessive pruning limits photosynthesis and reduces recovery.

If eggs have already hatched, what now?

Lightly clean up the worst twig damage, then focus on plant health through summer: steady watering and a gentle organic feed.

What feeding routine do you recommend?

Use an organic emulsified fish fertilizer (e.g., Neptune’s Harvest Fish & Seaweed) about once every 7 days, and maintain deep, consistent watering.

Should I spray insecticides?

For already hatched eggs and general recovery, spraying is rarely helpful. Support plant health instead. Consult a professional for site-specific advice.

How do I recognize cicada damage vs. disease?

Look for neat, repeated slit marks and flagged tips on the newest twigs. Secondary disease can enter through those openings, so continue monitoring.

When will this happen again?

Periodical cicadas follow long cycles. Use this season’s notes to plan protection for young trees before the next emergence in your area.