Efficacy of insect-exclusion nettings and shade cloth combinations on diversified vegetable production in the Southwest

Project Overview

Project Type: Farmer/Rancher
Funds awarded in 2023: $19,320.00
Projected End Date: 03/31/2024
Host Institution Award ID: G281-23-W9982
Grant Recipient: Highwater Farm
Region: Western
State: Colorado
Principal Investigator:
Rebecca Gourlay
Highwater Farm

Information Products


  • Vegetables: broccoli, cabbages, cucurbits, greens (leafy)


  • Crop Production: row covers (for season extension), season extension, shade cloth
  • Pest Management: biological control, cultural control, row covers (for pests)

    Proposal summary:

    This project seeks to address the loss of yields and marketability of vegetables due to the combination of insect pest damage and weather conditions. Insect-exclusion netting offers a tool for producers to reduce pest populations without chemical intervention. However, these row covers often create microclimates of increased temperature and humidity that can decrease the germination and overall yields of heat-sensitive crops.

    The Community Supported Agriculture (CSA) model is economically beneficial for farmers by providing  income in the beginning of the season when start-up costs are high and yields are generally low.This partnership requires the farmers to provide an abundance of high-quality, diverse vegetables for the duration of the CSA - often spanning 18 to 20 weeks, which is often challenged by pest pressure and extreme temperatures especially in spring and fall.  

    In order to make small-scale vegetable farming economically viable in the Southwest with the CSA model, research is needed to determine the effectiveness of different types and combinations of insect netting and shade cloth to successfully mitigate pest damage while also balancing out in field temperatures and moisture/water retention. This project seeks to incorporate row covers and insect-exclusion netting to manage pressure and mitigate environmental stressors of high temperature and low moisture to determine how to generate the highest yields and quality of ten vegetable crops. 

    A field day will be held on the farm to demonstrate best practices and findings with other farmers in the area, using the Roaring Fork Farmers and Ranchers group and the regional chapter of the Rocky Mountain Farmers’ Union to inform and educate other local producers. 1-2 presentations by the PI and TA in the fall and winter of 2023 will also share results. These presentations will be recorded via film and posted to social media upon completion.

    Project objectives from proposal:

    Research Objectives

    Objective 1: Compare and document yield and quality of crops grown with insect-exclusion netting and/or shade cloth materials to crops grown without insect-exclusion netting and/or shade cloth. 

    Objective 2: Help farmers increase the marketability and profitability of produce (specific crops) by reducing average yield loss from insects, and high temperature and aridity. 

    Objective 3: Share our findings and practices with other vegetable producers in the Colorado River and Roaring Fork Valleys of Colorado who face similar challenges of excluding pests with row covers while also creating optimal temperature and moisture for crops in increasingly extreme growing conditions. 

    Objective 4: Master growing techniques using described resources and found knowledge to provide enough diversity to support a 100 member (CSA) program with chemical-free produce from June to October.

    Education Objectives

    Objective 1: Build awareness with local community members around the challenges of growing vegetables in the arid Southwest. 

    Objective 2: Host an on-farm field day for farmers to share results and knowledge gained from research project and demonstrate to other local producers best practices for incorporating shade-cloth and insect-exclusion netting. 

    Objective 3: Synthesize data from the study, and present knowledge gained and challenges to other local producers. 

    Objective 4: Create a one page project summary with a description of the crops studied and best practices (insect-exclusion netting and shade cloth combinations) that can be shared among producers and passed on to Highwater Farm staff for the 2024 and 2025 growing seasons. 

    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.