Trellising provides vertical support for climbing plants, greatly benefiting pea growth and production. Vining pea varieties use specialized structures called tendrils to climb, and a string trellis gives them the necessary structure to grab onto. Growing peas vertically keeps foliage off the ground, improving air circulation around the plants. This increased airflow helps reduce damp conditions that promote fungal diseases like powdery mildew and minimizes the risk of rot. Trellised peas are also much easier to locate and harvest, leading to a higher yield and cleaner final product.
Preparation: Materials and Timing
Selecting the correct materials is the first step in constructing a durable and effective string trellis system. For the string, biodegradable materials like jute or hemp twine are commonly favored because they can be composted with the spent vines at the end of the season. These natural fibers also offer a slightly rough texture that pea tendrils can grip easily. While synthetic twines, such as nylon or polypropylene, offer greater strength and resistance to moisture, they require separation from the plant material for disposal. The frame requires sturdy support posts (T-posts, treated wooden stakes, or thick bamboo poles) and a heavy-gauge wire or a rigid top crossbar to anchor the string. The ideal time to install this support system is immediately after planting the seeds or when the pea seedlings are only 4 to 6 inches tall, well before the vines begin to tangle.
Setting Up the Basic Frame
The stability of the trellis depends on a rigid frame structure. For a row of peas, two end posts must be driven into the ground to a depth of at least 1 to 2 feet to withstand the string tension and the weight of the mature vines. Posts should be spaced no more than 6 feet apart to prevent excessive sagging. After setting the end posts, secure a strong horizontal wire or wooden crossbar between them to establish a top anchoring point. This top line absorbs the upward tension from the vertical strings, distributing the load evenly across the structure.
Step-by-Step Guide to Stringing
The stringing process depends on the preferred support style, with two main methods suitable for peas: the vertical drop and the horizontal weave. The vertical method, often used for determinate varieties, involves running a heavy-gauge wire or string across the top bar, then dropping individual strings down to the soil. Each vertical string is anchored at the base of the plant, often by tying it to a small stake or pinning it to the ground with a wire staple. This creates a dedicated climbing path for each pea plant, maximizing vertical growth and plant separation.
The horizontal weave method, sometimes called the Florida weave, provides continuous support by creating a ladder-like channel for the peas to grow within. To start, tie the twine to the first end post about 4 to 6 inches above the soil line and pull the string tightly to the second post, wrapping it once around the post before returning to the start. Running the string back and forth between the two posts creates a double line, or channel, that cradles the pea vines. New horizontal lines should be added every 6 to 12 inches in height as the plants grow, maintaining a high degree of tension with each pass. The tension applied during the stringing process is important, as slack lines will not provide adequate support once the vines become heavy with pods.
Guiding the Pea Vines and Maintenance
Once the stringing is complete, the young pea plants may require some initial guidance to ensure their tendrils connect with the support. Gently loop the main stem of the vine around the nearest string or tuck it under the lowest horizontal line, especially during the first foot of growth. This initial training helps the pea plant establish its upward trajectory, after which its own tendrils will naturally seek and wrap around the string. Ongoing maintenance involves checking the tension of the horizontal lines, particularly after heavy winds or rain, and tightening them to prevent collapse. At the end of the growing season, if compostable twine was used, the entire plant and string structure can be cut down at the base and added directly to the compost pile for easy cleanup.