How Trellises Make Cold Climates Warmer (and Your Garden Bigger)
Trellising in cold climates is today’s most neglected gardening practice.
All our grandparents used trellises, because many peas, beans, cucurbits, and tomatoes climb by nature. Trellises are also multifunctional: you can use them to build a permanent barrier edge (windbreak, weed barrier), deciduous or permanent shade (which creates a microclimate effect for your garden and house), and they yield mulch. Moreover, it’s possible to grow both annual and perennial crops on them. That said, trellising is making a comeback, thanks to seasoned permaculture insiders who refuse to forfeit its benefits.
How absurd would it be to bring this practice back into every garden?
In this edition, in 7 minutes or less:
#1 Multiplying yield
#2 How to position your trellis
#3 Trellis can save people from heatstroke
Multiplying yield
Because trellises let you use your vertical space productively and create microclimate effects, placing one in your garden will start multiplying your yield almost as soon as it’s up.
That makes trellising the single most important space-saving practice for both urban and rural gardens.
- Perennials: hops, ivy (English, Boston, and Engelmann), rambling and climbing roses, blackberries, raspberries, climbing honeysuckle, bittersweet
- Deciduous: grape, wisteria, hardy kiwi (Actinidia arguta, hardy to roughly zone 4), Arctic kiwi (Actinidia kolomikta, hardy to zone 3 and bearing small edible fruit), trumpet vine, Virginia creeper, clematis (many cultivars hardy to zone 3)
- Annuals: cucumber, melons, squash family, beans and peas, tomatoes (need to be treated as a vine), scarlet runner beans (edible pods and flowers, tolerant of cold soil, and a strong pollinator draw), nasturtiums (edible flowers and leaves, cold-tolerant, and a useful companion or trap crop), hyacinth bean (fast-growing, with ornamental edible pods)
However, positioning your trellis in the right place in relation to your garden is crucial.
Not only vines trellis
A trellis, in its simplest definition, is an open framework or lattice — traditionally built from wood, bamboo, or metal — designed to support climbing or sprawling plants. The idea is ancient: the Roman writer Pliny the Younger described trellised gardens nearly two thousand years ago, and by the French Renaissance, trellis-building (treillage) had become a specialized craft of its own. Today, trellises range from a simple row of bamboo poles to elaborate structures built into a house wall.
Vines are plants with specialized structures that let them naturally climb or twine onto a structure like a trellis, with little or no help from the gardener. There are four main ways they do this: tendril climbers (peas, grapes, passionflower) send out thin, wiry tendrils that spiral around narrow supports; twining stems (pole beans, hops, wisteria) wind their whole stem around a post or wire; twining leaves (clematis) wrap their leaf stalks around thin string or twigs; and adhesive climbers (Virginia creeper, Boston ivy) stick directly onto flat surfaces using touch-sensitive pads or clinging aerial roots.
Non-vines that can be trained upward on a trellis are plants that don’t naturally “attach” to a structure, but that benefit from being supported by one anyway. This includes scramblers — like climbing roses and bougainvillea — which have long, flexible (often thorny) stems that need to be tied in by hand; herbaceous plants; woody plants; and plants with weak stems that would otherwise sprawl across the ground or lodge under their own weight.
How to position your trellis
In tropical and desert climates, trellising over the garden is a core strategy. In cold climates, however, it should be avoided, because you don’t want to shade your other plants.
In this situation, place trellises in the garden only for smaller climbers. Melons and squash are better placed on outer garden fences, or up arbors and roofs. Use trellises to build fences and windbreaks, focusing more on their functional role than on yield — that’s the optimal placement for them, even though you’ll still harvest from them.
For productive trellises, align them north–south for even sun exposure.
- Vertical zigzag
- Inverted “V”
- House wall
- Garden fence
Not all plants attach to a trellis the same way, so you have to build sturdy trellis structures that match the plant’s climbing mechanism: mesh for tendril climbers (grape and passionflower), poles for twiners (beans), walls for plants with adhesive pads (Virginia creeper), and solid support for scrambler species (bougainvillea), as depicted in figure 5.8.
Be careful not to let rampant vines and berries get out of control. This warning is actually a positive thing, because it means that if you have “this problem,” you’re getting a very big yield of berries and mulch.
What would your garden look like with trellises?
Trellis can save people from heatstroke
Many architects interested in organic, sustainable construction, like Rudolf Doernach and Hundertwasser, placed trellises on the external walls of buildings to create a better microclimate. They point out that this was extensively practiced in the past, and since they brought it back, it has shown great effect.
As a permaculturist, I find it exciting because the walls of the house become part of the garden—even part of a forest ecosystem, if you will. That’s holistic design. Moreover, it’s noteworthy that trellises are essential strategies in tropical, desert, and cold climate zones alike. In warmer climates, they excel especially at creating shade and preventing evaporation (let’s not forget some vanilla is a climber plant!), while in cold climates they provide a windbreak against cold winds, maximize limited sunlight through vertical growing spaces, and improve the thermal performance of the house, which is the most complex structure in cold climates, since it must be solid and well-insulated to keep people warm in winter, but also cool in summer.
Does it sound impossible that you can extend your garden to your walls while making your house more comfortable year-round?
Trellising is a quintessential practice.
It is so effective and easy to deploy that it is used in every climate — wherever it receives the proper adaptation for the regional conditions. In cold climates, it is endorsed both by sustainable gardeners, like Bill Mollison, and architects, like Rudolf Doernach and Friedensreich Hundertwasser. Trellising excels at:
- Save space
- Used for perennials and annuals
- Placed against an existing structure or built as a free-standing structure
- Create productive barriers
- Create microclimate for both garden and house
- Yield cultural important products, like hops, grapes, berries, kiwi, and cucumber.
That’s right.
