Maximum Yield USA May 2018 | Page 42

climbing plants Twining climbers Examples: Pole beans, mashua, kiwi fruit Support with: Beanpoles and canes in wigwams or A-frames, post-and-wire systems Other climbers are twiners, winding leaves or stems around their supports as they grow. These are the plants that grow straight up a tree in the wild. Some, like the strangler fig, throttle the host plant to death, leaving the climber free-standing like a hollow pole. Luckily, twining vegetables aren’t anywhere near as aggressive, though they do tend to be among the most vigorous plants. Pole beans wind round supports with hawser-like strength. Some plants, like mashua, use their powerful petioles (leaf stems) to hold on as the plant climbs. Stem twiners like thicker supports up to three inches in diameter, so build them a sturdy wigwam or A-frame of hazel poles. Leaf twiners need something finer to wrap around, so give mashua slimmer poles, such as bamboo canes, Training can or a post-and-wire framework to grow up. sometimes seem “ technical, but it all uses the same basic principle: you develop a stem framework, then shorten any side shoots to persuade them to bear fruit instead of developing into extra branches.” Scrambling climbers Examples: Tomatoes, sweet potatoes, squash, blackberries and other cane fruit Support with: Trellis, post -and-wire systems, beanpoles, canes This group includes all sorts of plants that aren’t, strictly speaking, climbers. They evolved to scramble but don’t change chemically when they hit a vertical object like true climbers do, so they don’t hold onto things by themselves. They don’t bother to grow a strong, self-supporting stem either, preferring instead to ramble about on the ground until they find a nice sunny spot where they can fruit. Some have developed adaptations to help them along, like the thorns on blackberries, which hook themselves onto any struc- ture they come across to help the stems leapfrog across vast distances. Squash have tendrils and though they can use them to climb over other plants, they drape over the top rather than holding on tight. In the garden, scramblers are easily persuaded upwards onto trellis, wigwams, or arches, though you’ll need to tie them in regularly as they won’t hold on by themselves. Train indeterminate tomatoes as cordons (see below). TRAINING RELUCTANT CLIMBERS Plants enjoy many benefits when they climb. They’re able to grow quickly since they don’t have to generate woody stems, meaning they can afford to flower and fruit prolifically too. They don’t need large expanses of bare earth, just a foothold alongside something to clamber up. They’re also adaptable and flexible, making the most of sunshine to ripen their fruit. All these are also good reasons to persuade plants to grow like climbers when they wouldn’t normally do so. Training can sometimes seem technical, but it all uses the same basic principle: you develop a stem framework, then shorten any side shoots to persuade them to bear fruit instead of developing into extra branches. There are three main formulas, each used for different types of crop: Cordons Used for: Tomatoes, apples, gooseberries, redcurrants A single stem with side shoots trimmed back so the plant concentrates on fruiting rather than producing any extra vegetative growth. Tomato cordons are trained vertically onto a cane, and the side shoots are snapped out completely at the junction between leaf and main stem. Fruit cordons, on the other hand, are usually grown at 45 degrees from vertical, as this prompts the plant to produce more fruiting spurs, and the side shoots pruned back rather than removed completely. When to prune: In winter while establishing and in summer for shaping and maintenance. Tomatoes are pruned continuously throughout the growing season. Getting started (Fig. 1, next page): Plant trees at a 45-degree angle and add a cane for support and to keep the stem straight, tied in to the support wires. Leave the leader and any short side shoots unpruned to begin with, but trim back any side shoots longer than four inches to three buds. 42 feature