Protective netting is a physical barrier used in the cultivation of tomato plants to shield them from external threats. Often referred to as a row cover, this barrier excludes damaging organisms without the use of chemical controls. Its primary function is to prevent common pests, such as the tomato hornworm, aphids, and whiteflies, from accessing the foliage and fruit. Netting also protects against environmental stressors like strong winds and light frosts, creating a more stable microclimate around the plants.
Gathering the Necessary Materials
Selecting the correct material is the first step in establishing an effective protective system. The specific threat determines the required mesh size; fine insect netting (e.g., 25×50 mesh) is necessary to exclude tiny pests like whiteflies and fruit flies. Floating row covers, made from lightweight spunbond polypropylene fabric, are a common choice because they allow light, air, and water to pass through freely. For the structural components, use flexible materials like half-inch diameter PVC piping or galvanized metal rods to form the support hoops. To secure the system, you will need fabric clips or clothespins to hold the netting to the frame, and U-shaped garden staples, heavy rocks, or bricks to anchor the edges firmly to the ground.
Erecting the Support Framework
A successful netting installation relies on a robust support framework that prevents the cover from resting on the tomato foliage. If the netting touches the plant, insects can bite through the fabric, and restricted airflow encourages fungal diseases. Begin by measuring the planting area and cutting the flexible support material to length; a 10-foot length of PVC or metal rod creates an appropriate arch for a typical 4-foot wide garden bed. Insert these rods into the soil at regular intervals, approximately every four to six feet, along both sides of the tomato row. For added stability, you can drive short pieces of rebar or wooden stakes into the ground first and slip the PVC pipe over them as anchors. The arch must be tall enough to accommodate the mature height of the tomato variety, often requiring a clearance of four to six feet.
Applying and Anchoring the Netting
Once the support hoops are securely in place, drape the netting over the structure to create a sealed tunnel. Unroll the fabric and lay it smoothly over the arches, ensuring sufficient slack to allow for the plant’s continued vertical growth. Allow for an extra foot or two of material at each end of the row. Completely sealing the perimeter is the most important step to prevent pest infiltration, as any small gap compromises the barrier’s effectiveness. Use garden staples or bricks to firmly anchor the netting to the ground, or bury the edges in a shallow trench of soil for the most secure seal. Inspect the entire run, paying attention to corners and seams where the netting meets the ground, to ensure no entry points remain for crawling or flying insects.
Management and Maintenance
After installation, the netted tunnel requires ongoing attention to ensure the health and productivity of the tomato plants. Tomato flowers are structurally self-pollinating, containing both male and female parts, and do not strictly require external pollinators like bees. However, the pollen must be physically agitated, a process known as buzz pollination, typically achieved by wind or bee vibrations. If using a fine-mesh barrier that restricts air movement, you must lift the cover during mid-morning hours when temperatures are below 85°F to allow for natural wind movement, or manually vibrate the flowers. Periodically, lift a section of the netting to check for any trapped pests that may have emerged from the soil or been covered inadvertently. The netting must also be momentarily lifted or unclipped for routine tasks such as harvesting, pruning, or deep watering. Take care to reseal the edges immediately afterward to maintain the protective environment.