Peas are popular cool-season vegetables grown worldwide. Many types of garden peas, specifically the taller varieties, possess a natural climbing mechanism that requires vertical support. Not all pea plants climb, as some shorter varieties are bred to be self-supporting. Understanding the growth pattern of the specific pea plant is necessary for successful cultivation.
The Mechanics of Pea Climbing
Climbing pea plants utilize specialized structures called tendrils, which are modified leaflets. These slender, thread-like appendages emerge from the stem and continuously move in a circular pattern, a behavior known as circumnutation. This movement increases the plant’s probability of encountering a suitable vertical support.
Once a tendril makes contact with an object, it triggers thigmotropism, a rapid growth response to touch. The side touching the support slows its growth, while the opposite side grows rapidly, causing the tendril to coil tightly around the structure. Sustained contact leads to an irreversible coiling that provides a secure anchor for the weak stem. The coiling action pulls the stem closer to the support, allowing the vine to continue its upward ascent toward sunlight.
Understanding Vining and Bush Varieties
The need for a climbing structure depends entirely on the variety of Pisum sativum being grown, which are broadly categorized into vining and bush types. Vining or climbing peas are characterized by their tall stature, often reaching heights between 5 and 7 feet, and sometimes even up to 10 feet with adequate support. These types bear their crop over an extended period, requiring continuous vertical support to prevent the heavy vines from sprawling on the ground.
Bush or dwarf varieties are bred to be more compact, typically growing between 1.5 and 3 feet tall. These shorter plants are often self-supporting or need only minimal staking to keep their stems upright. Dwarf types generally produce their pods in a concentrated harvest period, making them suitable for container gardening or small spaces. Check the seed packet for terms like “dwarf,” “bush,” or “vining” to determine the plant’s expected size and support requirements.
Practical Support and Trellising
Providing a trellis or support system for vining peas is a practical necessity for maximizing yield and maintaining plant health. Taller varieties require structures that are at least 6 to 7 feet high, though a 5-foot structure is often adequate for many common cultivars. The support should be installed early, ideally before the seeds are planted, to avoid damaging the delicate roots later in the season.
Effective trellising materials include wire mesh, sturdy garden netting, or natural options like bamboo teepees and brushwood (sometimes called “pea brush”). Tendrils are adapted to wrap around thin objects, so supports with a smaller diameter, such as twine or wire fencing, are more effective than thick wooden posts. Encouraging vertical growth promotes better air circulation, which reduces the risk of fungal diseases like powdery mildew and keeps pods clean and easy to harvest.