Give each climbing food plant its own sturdy support, or grow it up a tree only once that tree is large and well established, because a vigorous vine such as grape or hardy kiwi can shade out and break a young or small tree. Vines add a high-yield layer that uses vertical space and little ground, but they need annual pruning, heavy-duty supports and a place where their weight cannot bring down a tree. Cook scarlet runner beans before eating them, since raw beans of this kind are toxic.
The vine layer is the group of climbing food and utility plants, such as grape, hardy kiwi, hops and runner bean, that use trees and structures as their support in a food forest.
A Vine Uses Another Plant’s Height And Can Overwhelm It
The carrier lists grape, hardy kiwi and hops among the fruit vines and scarlet runner bean (a nitrogen fixer and food) and passionflower (where the climate allows) among the utility vines. All of them gain height by borrowing a support; the question for the designer is what that support is and whether it can bear the load.
A vine grown on a living tree adds weight to its branches and competes with it for light. Grape and hardy kiwi are vigorous enough to overtop a small tree; a mature, large canopy tree with strong limbs is the safer host.
Method: Give The Climber A Support It Cannot Overwhelm
Step 1: Prefer a dedicated structure for heavy fruiting vines: a post-and-wire trellis, an arbour, or a pergola of rot-resistant timber. A fruiting grape or kiwi vine, loaded with fruit and wet with rain, carries a large weight in its canopy; build posts to bear it.
Step 2: Use living trees only when they are mature. Plant the vine at the base of a large tree and train the first shoots with a stake and string, since a vine planted tight to a trunk gets little rain.
Step 3: Prune every year. Hardy kiwi and grape need regular pruning to keep fruiting wood within reach. Hops die back to the ground each winter and are cut down in autumn.
Step 4: Keep climbers away from the tree’s crown if the tree is a fruit tree you want to harvest. A vine in the crown of an apple makes the apple hard to prune and pick.
Step 5: Protect the ground at the foot with mulch; these plants use a great deal of water in summer.
Common Mistakes
- Planting a vine at the foot of a young tree — within a few years the vine has the crown.
- Underbuilding the support — a trellis that carries a young vine fine fails when the vine matures.
- Letting hops or runner beans seed everywhere — they are strong self-sowers in suitable climates.
Safety
Cook runner beans and use sound ladders
Raw or undercooked beans of the common bean group, including scarlet runner beans, contain a lectin that causes severe vomiting; boil dried beans thoroughly before eating. Pruning and picking vines on high trellises is done from a ladder: set it on firm ground and keep three points of contact.
What’s Next
- Learn next: Guild Planting — how climbers fit into plant groups
- Combine with: Pruning and Maintenance Schedule — when to prune each vine