The Air Above Your Garden Is Empty
A standard 4×8 raised bed contains 32 square feet of soil. The cube of air above it — six feet up — holds 192 cubic feet of growing volume that almost no garden ever uses. Most of us tend the floor and leave the room empty. Vertical gardening is the recognition that the third dimension costs nothing.
A trellis occupies the same patch of ground as a tomato cage and returns several times the food. Mount a pocket wall on a sunny exterior and three feet of bare brick becomes a standing salad; train a vine up a porch railing and it reaches light at the height where the surrounding buildings throw the least shade. None of this is exotic. It is mostly a matter of giving a plant something to climb and then getting out of its way.
Three Vertical Strategies
Vertical gardening is not one method but three related ideas, each asking something different of the gardener:
1. Climbing crops on structures. Plant something that wants to climb, then give it a trellis, a fence, a length of wire — pole beans, peas, cucumbers, vining tomatoes, malabar spinach, hardy kiwi, hops, scarlet runner beans. The plant does the labor of going up; you only have to hold the line for it.
2. Stacked planters and pocket walls. Container systems that set soil pockets at several heights at once — felt pocket walls, stacked terra cotta, ladder shelves of pots, lengths of gutter fixed to a fence. Each pocket is its own small garden, and together they make a wall of food.
3. Living walls. Engineered systems that build the plants into the wall itself, irrigation and all. They are handsome and they are costly, and for a home grower they are usually more than the task requires. The simpler approaches above grow more food per dollar.
Climbing Crops Worth Growing
Plants that climb naturally, with how much vertical space they want:
- Pole beans — 6–8 feet. Most prolific climber per square inch of soil. Plant six seeds at the base of a sturdy bamboo tripod and feed a family.
- Sugar snap peas — 4–6 feet. Cool-season counterpart. Trellis with chicken wire or sticks.
- Cucumbers — 4–6 feet. Need a sturdy structure; the fruit is heavy. Trellised cukes are straighter, healthier, and easier to harvest.
- Indeterminate tomatoes — 6–8 feet if you let them. Stake or string-train them up. One plant produces more in vertical space than three in cages.
- Malabar spinach — 6–10 feet. A heat-loving climbing green with red stems. Beautiful, edible, drought-tolerant.
- Scarlet runner beans — 8–12 feet. Red flowers covered in hummingbirds, edible pods and beans.
- Hardy kiwi (Actinidia arguta) — 15+ feet. Perennial vine, takes 4–5 years to fruit, but produces grape-sized fuzzless kiwis for decades.
- Hops — 15+ feet. Aggressive perennial vine. The cones are useful for brewing and herbal sedatives.
Structures
A fancy trellis can run you a hundred dollars. It does not need to. Five structures worth knowing, from the cheap end up:
Bamboo tripod. Three 8-foot poles lashed together at the top, beans climbing the legs. It costs $5 and lasts three seasons.
Cattle panel arch. A 16-foot cattle panel bent into an arch between two beds, about $30 of materials. Cucumbers and small squash climb up one side and over the top, and walking under the green tunnel they make is one of the better small pleasures a garden offers.
Florida weave. T-posts set every 6 feet with twine woven between them at rising heights as the tomatoes grow. The cheapest tomato support there is. Pull it down at season’s end and the posts come back next year.
String trellis. A horizontal wire at 8 feet with twine dropped to each plant, the plants clipped on and trained upward. It is what most commercial high tunnels use for tomatoes and cucumbers.
Cattle-panel A-frame. Two cattle panels leaned together into an A. The shaded inside holds lettuce that would bolt in open heat; the vines climb the sunny outside.
The Apartment Version
My first garden was a balcony of containers, the summer everything closed, so I have a particular tenderness for the small vertical tricks that work where there is no ground at all. For balconies, railings, and walls:
Felt pocket planters mount on nearly any vertical surface and grow strawberries, herbs, lettuce, and trailing nasturtium without complaint. Look for panels of 6 to 10 pockets in UV-stable felt, so they survive more than a single season in the sun.
Railing planters straddle a standard railing. Let strawberries or sweet alyssum spill over the outside edge and tuck compact herbs into the bed.
String trellis on a wall. Eye hooks along the top of a sunny wall, twine dropping to climbers planted in containers at the base. The wall works as structure and heat sink at once.
Our patio garden guide covers more apartment-scale vertical strategies.
The Frame
A garden that grows upward rather than outward handles space the way the living world already does — in layers, in strands, in things reaching past one another for light. A forest is vertical. A meadow is vertical too, once you crouch down and look. The flat, single-layer plot is the strange exception we invented; the column of green climbing toward the sun is the older pattern, and the one a trellis simply lets back in.
Put up one trellis this season and plant a single thing that wants to climb. Come next summer, weigh what comes off the same patch of ground. The air above it was never empty. It was only waiting to be woven into.
Frequently Asked Questions
What is vertical gardening?
Vertical gardening is the practice of growing plants upward rather than outward — using trellises, wall planters, pocket walls, towers, and climbing crops to multiply growing space in a small footprint. A 4-foot trellis can double or triple the yield of a 4-square-foot patch by giving climbers (beans, cucumbers, peas, squash) vertical room.
What plants are best for vertical gardening?
Climbers: pole beans, peas, cucumbers, vining squash, tomatoes (with support), nasturtiums, climbing spinach (Malabar). Wall pockets and towers: lettuce, herbs, strawberries, kale, chard. Hanging baskets: cherry tomatoes, strawberries, trailing herbs, peppers. Vertical systems work best with shallow-rooted, fast-maturing crops.
How do vertical gardens save space?
By converting unused vertical air space into growing surface. A 4×8 conventional bed has 32 square feet of growing area; the same bed with a 6-foot trellis added has effectively 80+ square feet because climbing crops use the column above the bed. Apartment balconies and small yards routinely double their food output by adding vertical structure.
Are vertical garden walls worth it?
It depends. DIY pocket-wall systems made from felt, pallets, or recycled materials are excellent value. Commercial 'living wall' systems are often expensive and require sophisticated irrigation. Start with a simple trellis or pallet wall before investing in any commercial system. The cheap version usually outperforms the marketed one.
Can I grow tomatoes vertically?
Yes — indeterminate tomato varieties are ideal for vertical growing. Stake or trellis to 6+ feet, prune to one or two main stems, and tie up weekly during the growing season. A single vertical tomato plant can produce 20+ pounds of fruit in the footprint of a single square foot. Determinate (bush) varieties don't benefit much from vertical training.
Written by E. Silkweaver