Supporting Natural Enemies of the Cabbage Aphid with Hedgerow Plantings

Project Overview

Project Type: Professional + Producer
Funds awarded in 2018: $48,554.00
Projected End Date: 03/31/2021
Grant Recipient: Wild Bee Project
Region: Western
State: Utah
Principal Investigator:
Laura Horn
Wild Bee Project


  • Vegetables: greens (leafy), kale


  • Education and Training: demonstration
  • Natural Resources/Environment: hedgerows
  • Pest Management: biological control


    Our project seeks to expand the adoption of Conservation Biological Control practices for aphid
    management on vegetable farms in northern Utah and the Intermountain West. Most farmers in
    the region are faced with significant hurdles in learning and upfront costs required to implement
    such practices. Aphid control is a fruitful “introduction” to Conservation Biological Control as
    aphids have many natural enemies, and are a persistent problem for vegetable growers. Cabbage
    aphid problems in particular have increased in recent years, as more farmers in the region grow
    kale and other brassica crops year-round to meet customer demand.
    Our project will establish aphid-control hedgerows at six farms, three of which will be used as
    demonstration sites. Hedgerows will be evaluated for their potential to attract
    natural enemies of cabbage aphid and to reduce aphid damage to cole crops, using associated
    control plots (at varying distances from hedgerows) for comparison.
    Education and outreach components of the project focus on building knowledge and visibility of
    Conservation Biological Control practices at the grassroots level, and on making connections
    among urban vegetable growers and the ways they implement Conservation Biological Control strategies in our region. We will extend Conservation Biological Control education and the results of this study to growers throughout
    the Intermountain region with USU Extension or other publications, with an emphasis on the cost-benefit analysis of incorporating long-term Conservation Biological Control strategies such as hedgerows for pest control.
    Our project attempts to lower the barriers to adoption of Conservation Biological Control
    practices by emphasizing 1) that Conservation Biological Control is just formalizing and expanding on practices many farmers are already implementing, 2) Conservation Biological Control plants can be chosen for their direct profit potential (culinary or medicinal herbs, seeds, or bouquets for sale), and 3) the multiple resource conservation benefits of hedgerows specifically (e.g., reducing soil erosion, filtering runoff, preventing weed encroachment).

    Project objectives:

    Objective 1. Evaluate whether hedgerows attract natural enemies of cabbage aphid

    Objective 2. Evaluate whether fewer cole crops reach economic loss thresholds with

    Objective 3. Use established hedgerows and outcomes of this study (Objectives 1 and 2) to
    support broader education goals with Conservation Biological Control through
    presentations to urban and small-acreage vegetable farmers.

    Objective 4. Encourage grower-to-grower information exchange regarding Conservation
    Biological Control with workshops or farm tours at demonstration farm sites.


    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.