From our perspective as sweet pea plants (Lathyrus odoratus), the answer is a resounding yes. We are not idle shrubs content to grow in a bushy form; we are annual climbing vines. This is an intrinsic part of our biological design. Our stems produce specialized structures called tendrils. These thin, thread-like extensions are our primary tools for exploration and ascent. They reach out from our main stem, gently waving in the air until they contact a suitable support. Upon contact, they coil and clasp with remarkable strength, anchoring us securely. Without a structure to grasp, our tendrils find nothing to hold, and our growth strategy fails. We are programmed to climb, and a trellis fulfills this fundamental need.
A trellis or other support structure is not a mere gardening suggestion; it is critical for our vitality. When our long, trailing vines are allowed to sprawl on the damp ground, we become profoundly vulnerable. The lack of air circulation creates a humid microenvironment that encourages fungal diseases like powdery mildew and botrytis, which can quickly devastate our foliage and beautiful blooms. Furthermore, soil-borne pests find it much easier to access our stems and leaves when we are at ground level. By growing vertically on a trellis, we remain airy and dry, our leaves bask in the sunlight more efficiently, and we are kept safely away from many soil-related dangers. This directly translates to a stronger, healthier plant capable of producing more flowers.
Our ultimate purpose, from a biological standpoint, is to flower and set seed to reproduce. To do this effectively, we require immense energy from the sun. A tangled, ground-bound mass of vines creates a canopy where upper leaves shade out lower leaves, drastically reducing photosynthesis. A trellis allows us to distribute our foliage evenly, with each leaf having better access to light. This maximizes our energy production, which we can then divert into creating larger, more numerous, and more fragrant blooms. Furthermore, when our flower-laden stems are held upright, they are far more visible to pollinators like bees and butterflies, increasing the chances of successful pollination. For you, the gardener, this also means the flowers are displayed at eye level, making them easier to appreciate and harvest for bouquets.
While "trellis" is the common term, we can successfully climb many forms of support. The key feature is something thin enough for our delicate tendrils to wrap around. Ideal options include obelisks, tripods made from bamboo canes or branches, wire or mesh panels, or even a simple frame of strings or netting suspended vertically. The material can be wood, metal, or plastic—we are not particular, so long as it provides a stable framework. It is crucial that this support is installed early, when we are young seedlings. Inserting a support later risks damaging our delicate and widespread root system. By providing a structure at planting time, you allow us to begin climbing naturally from the start, guiding our growth in the way we instinctively desire.
