For example, in traditional vegetable gardening, tomatoes sprawl over and around their cages. However, you can grow your tomatoes along a trellis, a post, or even a single strong string with relative ease. This method allows you to plant more tomato plants in your garden as you eliminate tomato plant sprawl.
My favorite method of vertical gardening—again, I’m a lazy gardener—is against stakes. This method has worked particularly well for me with tomatoes. I prefer wooden stakes that are an inch square and five or six feet tall. Simply buy as many stakes as you have tomato plants, and when you put the plants in the ground, set the stakes in the ground at the same time, being careful not to stab the roots of the young plants. As the young plants grow, gently tie the thicker branches of each plant to the stake, using either strips of fabric or a vinyl stretch tie.
For this method to work best–to keep the plant put its energy into growing up instead of out–you need to pinch off new growth at the point where the existing branches join the main stalk of the plant. I typically do this once a week; it only takes a few minutes, and once your tomatoes are trained up the stake, these little extra sprouts are easy to spot and remove.
This is an effective, but not necessarily the sturdiest or most attractive, way to grow vegetables vertically. If you’re looking to grow heavier vegetables–like squash or even pumpkins–vertically, you’re going to need something more substantial. If you’d like to see how to build a simple but tall and strong support for heavier plants, I recommend All New Square Foot Gardening by Mel Bartholomew, as the book has plans for constructing, with only a few tools, an affordable but substantial trellis. The book also explains where to situate your trellis (hint: don’t place it in such a way that the vegetables growing on the trellis will shade out those in the garden bed), how to best secure the netting that forms the ladders up which the plants climb, which plants grow best vertically, how to train plants up the trellis, how to increase your tomato yield by planting one tomato plant hortizontally (!), and how to secure the trellis if the plants become heavy at the end of the season.
If you’re ready to tackle slightly more advanced vertical garden methods–many of them exceptionally beautiful–I recommend you get your hands on the lavishly illustrated and highly inspirational book Garden Up! The book has a chapter on growing edibles up, against, and hanging from walls, with a special focus on how to irrigate plants in such a system. The chapter also covers growing on espaliers, using containers creatively in vertical plantings, making “potato condos,” and constructing nontraditional trellises.