A trellis is a must for some climbing plants, like peas and beans, and can be an inexpensive way to grow other vegetables in a small space or a non-traditional garden such as a roof, patio or urban garden. It's also great for older gardeners who don't want to be on their hands and knees in the dirt anymore. To grow vegetables on a trellis, choose plants that climb, with vine-type stalks, and pay attention to what kind of plants will grow well in your area.
Pea trellises can be put out in early spring, as peas produce their bounty earlier than many trellis vegetables. A-frame, simple wire mesh, fencing or even poles will all work with peas. Peas grow best in moist, well-drained soils, and can be grown on a single side of a trellis or both sides. Plant peas close to the trellis, and train them onto it when they are tall enough.
The types of beans that are grown on trellises are called pole beans. These have a long growing season and produce lots of beans, making them the most popular trellised vegetable. They grow quite tall, up to 15 feet, so keep this in mind when planning your bean trellis. They will grow on simple poles, fencing, wire mesh, or even strings tied between poles.
A common type of tomato trellis is the tomato cage, a wire mesh encircling the plant and supporting it upwards. Tomatoes can also be trellised against walls, on fences and up poles. Posts with string or mesh also work for rows of tomatoes, or they can simply be staked or framed.
Cucumbers and their relative, zucchini, trellis well on A-frames, poles, or teepee-style trellises. This is a construction of several poles leaning together in a cone shape, and often tied together with string. Untrellised cucumbers will sprawl and take up lots of garden space, so trellising is preferred by many gardeners.
Squash are part of a whole family of vegetable that can be trellised, including pumpkins and gourds. They can be placed on A-frames or teepee trellises. One change in these plants when trellised is that while more individual vegetables will grow, they will not grow as large, since the stem must support them vertically. To help the squash, pumpkins or gourds grow larger, tie slings under fruits that grow larger than a typical tomato. These can be rags, old pantyhose or cheesecloth strips, tied to the trellis, not the plant, and supporting the bottom and sides of the vegetable.
These can be caged or trellised much the same way as tomatoes. Mesh and fencing work fine with peppers, as do poles, since many peppers tend to grow straight and not vine as much as other trellis vegetables. Eggplants also fall into this category, and the precaution of putting slings around larger eggplants works here as well.
Many types of vine melons can be trellised; they actually are relatives of the cucumber. Muskmelons, cantaloupe, honeydew and even watermelons can be grown on trellises. These all need plenty of space; they will grow 6 to 8 feet tall. This method of melon growing yields fewer fruits than ground crops, but produces larger melons, on average.