Best Methods to Safeguard Gardens from 17-Year Periodical Cicada Nymphs

Every 17 years, a remarkable natural phenomenon unfolds beneath the soil in many parts of North America: the emergence of the periodical cicada nymphs. These cicadas are known for their synchronized mass appearances, and while their phenomenon fascinates entomologists and nature lovers alike, they can pose significant challenges for gardeners. The nymphs feed on tree roots underground before emerging as adults, which can sometimes lead to damage in gardens, young trees, and shrubs.

This article explores effective methods to protect your garden from the impacts of 17-year periodical cicada nymphs. We will delve into their life cycle, potential damage they cause, and practical strategies to safeguard your plants.

Understanding the 17-Year Periodical Cicada

Before diving into garden protection, it’s crucial to understand the biology and behavior of these insects.

Life Cycle Overview

The 17-year periodical cicada (Magicicada spp.) spends the vast majority of its life underground as a nymph. During this long period, it feeds by tapping into the xylem of tree roots. After 17 years, synchronized signals trigger their mass emergence in spring or early summer as winged adults whose primary goal is reproduction.

Garden Impact

• Root Feeding by Nymphs: While feeding on roots, nymphs generally do not kill healthy mature trees but can stress young or weak plants.
• Egg-Laying Damage: Female cicadas lay eggs in slits they cut on small branches and twigs. This “oviposition” can cause flagging (branch dieback) in young trees and shrubs.
• Mass Emergence: The sheer volume of individuals can overwhelm gardens with noise and physical presence.

Understanding these behaviors helps gardeners anticipate and prepare for their arrival.

Identifying Potential Damage to Gardens

17-year cicadas primarily affect woody plants by:

• Severely damaging new growth on small branches through egg-laying cuts.
• Stressing saplings by root feeding.
• Occasionally causing breakage due to weight when large numbers land on small trees.

While mature trees often tolerate cicadas without long-term harm, seedlings and ornamental plants are at greater risk.

Best Methods to Protect Your Garden

Several strategies can minimize cicada damage effectively. Combining multiple approaches yields the best results.

1. Physical Barriers: Netting and Screens

One of the most effective ways to protect young trees and shrubs is by covering them with fine mesh netting before cicadas emerge.

• Material: Use lightweight nylon or polyester mesh with openings smaller than 1/4 inch to prevent cicadas from getting through.
• Timing: Install netting just before adult emergence (late spring). Ensure coverage remains until cicadas have finished laying eggs.
• Benefits: Prevents female cicadas from accessing branches to lay eggs; also reduces damage from nymph feeding by discouraging egg-laying that leads to weakened branches.
• Considerations: Secure netting well at the trunk or base to prevent entry; remove promptly after emergence to allow normal plant growth and pollination.

2. Delayed Planting of Vulnerable Species

If you know an emergence year is approaching, consider delaying planting newly propagated saplings or sensitive plants until after the cicada period passes.

• Newly planted trees and shrubs are most vulnerable in their first few months.
• Waiting until cicadas have completed their lifecycle underground reduces exposure.

3. Choose Resistant Tree Species

Some tree species show more resilience against cicada damage:

• Native hardwood trees such as oaks, maples, and ashes tend to tolerate cicada activity better.
• Avoid planting highly susceptible species like fruit trees or ornamental cherries immediately before an anticipated emergence.

4. Proper Pruning After Emergence

Once cicadas have completed egg-laying:

• Prune and remove damaged twigs showing flagging or dieback caused by oviposition wounds.
• Doing so promotes healthy new growth and prevents secondary infections.

Regular pruning also helps maintain tree vigor during stressful periods following emergence.

5. Mulching and Soil Health Maintenance

Healthy soil promotes strong root systems that can better withstand nymph feeding:

• Use organic mulches such as compost or bark chips around trees.
• Avoid over-fertilizing immediately before emergence; balanced nutrition supports root resilience.

Good soil moisture management reduces drought stress that can exacerbate damage effects.

6. Encourage Natural Predators

Periodical cicadas have many natural enemies including birds, spiders, rodents, and other insects.

• Maintain a garden ecosystem that supports these predators.
• Avoid broad-spectrum insecticides that harm beneficial species.

Predation naturally helps reduce cicada populations over time.

7. Limit Chemical Controls

Currently, there are no widely recommended insecticides for controlling periodical cicadas due to timing challenges and environmental concerns:

• Cicadas spend most of their lives underground feeding on roots, making chemical treatments ineffective.
• Spraying adults risks harming pollinators and beneficial insects.

Focus instead on mechanical controls like netting for safer management.

Preparing Your Garden: Timeline Summary

Following this timeline ensures optimal protection while minimizing disruptions to your garden’s ecology.

Additional Tips for Gardeners Facing Cicada Emergence

• Stay Informed: Local agricultural extensions often provide updates on upcoming emergences.
• Community Efforts: Coordinated neighborhood protections reduce overall population pressure.
• Enjoy Nature’s Show: Remember that periodical cicadas play important ecological roles including aerating soil and providing food sources for wildlife.

Conclusion

The emergence of 17-year periodical cicadas can be a challenging time for gardeners, especially those tending young or sensitive plants. However, with adequate knowledge and preparation using physical barriers like fine mesh netting, choosing resistant species, proper pruning practices, and maintaining soil health, you can successfully safeguard your garden from potential damage caused by these fascinating insects.

By embracing integrated approaches that respect ecological balance while protecting your valuable plants, you’ll enjoy thriving gardens for many cycles to come , long after the last cicada has sung its song.