The need for a trellis depends entirely on the specific pea variety being grown. Peas are broadly categorized based on their growth habit, which determines their need for vertical support. The two main groups are the compact, low-growing bush (dwarf) varieties and the taller, climbing vining (pole) varieties.
Understanding Pea Varieties and Growth Habit
Pea plants are separated into two distinct categories: bush (dwarf) and vining (climbing) varieties. Bush varieties are genetically programmed to remain compact, typically reaching 18 to 30 inches tall. These varieties, such as ‘Green Arrow’ or ‘Sugar Ann’, develop an upright, self-supporting structure. They are suitable for containers or smaller garden spaces, though light staking may help prevent sprawling in windy locations.
Vining pea varieties, like ‘Tall Telephone’ or ‘Super Sugar Snap’, exhibit a different growth pattern, often reaching 5 to 8 feet tall. These plants use specialized, thread-like tendrils to actively seek out and coil around any available support. Without a structure to climb, the vines will tangle on the ground, creating a dense, sprawling mat. A sturdy, tall trellis is necessary for these varieties to realize their full growth potential and produce a healthy harvest.
The Necessity and Benefits of Vertical Support
For vining peas, vertical support is a fundamental horticultural practice that promotes plant health and maximizes yield. Allowing pea vines to climb significantly improves air circulation around the foliage. This movement of air helps dry the leaves quickly after rain or heavy dew. Quick drying is a defense against common fungal diseases such as powdery mildew and rot.
Growing peas vertically ensures the entire plant receives better sun exposure, which is linked to higher yields and better pod development. When plants sprawl on the ground, lower leaves and pods are shaded, reducing photosynthetic output. Keeping the pods suspended in the air also makes them cleaner and easier to locate and harvest.
Elevating the developing pods prevents them from resting directly on the soil, deterring ground-dwelling pests like slugs and snails that can damage the crop. Vertical orientation maximizes garden space, allowing a greater number of plants to be grown in a smaller footprint. This technique also allows for a more extended harvest season for vining types, as they continue to produce new pods from side shoots.
Practical Trellis Options for Pea Plants
Since pea vines are lightweight climbers, their supports do not need to be heavy or complex, but they must be installed when the peas are first planted. A common and effective solution is simple pea netting or lightweight plastic mesh strung between two sturdy posts or stakes. Peas use their tendrils to grab onto supports less than a quarter inch in diameter, making materials like twine and thin wire ideal.
For a rustic appearance, many gardeners use the traditional method of “pea sticks” or “pea brush.” This involves thrusting small, branched woody stems or tree prunings upright into the soil. A popular option is a string trellis, which uses horizontal lines of twine strung between vertical posts or a wooden frame. Taller vining varieties require a trellis height of at least 6 to 8 feet. Simple A-frame trellises made from bamboo poles or chicken wire are also suitable, providing a stable structure that can be angled to maximize sun exposure.