A trellis covered in morning glories brightens up an old shed.
Garden in Three Dimensions with Trellises
First published on garden.org on March 1, 2007, by Suzanne DeJohn
Before you begin planting your garden, put on your 3-D glasses. Instead of imagining your garden as a flat canvas, look at it as a three-dimensional space. Picture plants growing up -- on trellises, fencing, tepees, arches, and arbors. How does it look? There are a number of reasons, both aesthetic and practical, for growing plants on vertical structures.
Maybe you're bored with flat beds of pansies flanking your front door. Picture an arched trellis covered with colorful morning glories to welcome visitors. Does your landscape need some some pizzazz? A rose-covered arbor and comfortable bench will transform it. Strategically placed, plant-covered trellises can shield you from a busy road and provide a bit of privacy. A vine-laden fence can block unsightly views.
Growing plants on vertical structures has other benefits, too. Gardenens with small spaces can maximize the use of that space by growing vining plants on trellises. Left sprawling on the ground, one cucumber plant can take up 15 square feet or more. Grow your cukes on a trellis, and you can have 4 plants in that same amount of space. Disease problems are minimized because plants receive better air circulation. Harvesting is easy and crops stay cleaner because they are suspended above the soil surface.
Use vines to shade a south-facing porch to make it comfortable even in the heat of summer. Likewise, vines growing up the south side of a building can help keep the interior of the house a little cooler.
Trellises in the Vegetable Garden
Many vegetable crops thrive when trained to a trellis. Vining plants, such as peas, cucumbers, pole beans, and summer squash are good candidates. Melons can be trained to a trellis, but you'll have to support developing fruit so its weight doesn't tear the vine or cause the whole setup to topple. Many vegetables are available in both "bush" types and "vining" types. Bush varieties remain relatively small, so for your vertical garden, choose vining or climbing types. For tomatoes, look for indeterminate, as opposed to determinate, varieties.
Before purchasing plants, evaluate the growing conditions at the site. Most flowering vines require full sun and rich, well-drained soil. Should you choose annual or perennial vines? Annual vines die at the end of the growing season, so you can change the "decor" every year. Although they may reach flowering stage later than some types of established perennials, once they begin to flower they usually continue to do so until frost.
Perennial vines may take a year or two to get established. Once they do, they usually have a distinct flowering period that may last several weeks to a month. Aside from annual pruning, perennial vines are usually relatively low maintenance -- and you don't need to replant each spring. Perennial vines that turn woody, such as wisteria, will need very sturdy supports. If you are using a trellis for privacy, look for perennial evergreen vines.
If you are looking for roses to adorn a trellis, choose varieties described as "climbers" or "pillars." These produce especially long canes that can be trained to a trellis. Canes that run horizontal produce more flowers than upright canes -- meaning that the arched top of your arbor will have more flowers than the vertical sides. Remember that roses have thorns! Avoid using them in places where passersby can inadvertantly brush against them. They're probably not the best choice for flanking a front door (unless you're trying to send a message to visitors). Most roses have a distinct bloom period that lasts for several weeks. Some types will continue to flower, albeit less abundantly, until the end of the growing season.
Know Your Vines
Not all vines can climb all structures, so it's important to match the plant to the support. For example, pole beans climb by twining around a support. Clematis use elogated leaf stalks to anchor themselves. Sweet peas climb by wrapping their tendrils around a support. Climbing roses don't really climb; rather, they form long canes that must be tied to supports. Many ivies climb by attached themselves with little adhesive disks.
Twiners can wrap around almost anything, but ideally a structure will have slats less than two inches across. You may need to help the vine find the support by tying it loosely to get it started. Plants that climb with tendrils climb best on trellises with narrower slats. If your vine has trouble climbing, install mesh netting over the slats. It will be nearly invisible, and give the vine a good foothold.