When should grape vines be cut back so that they grow back even better?

Most vines benefit from a pruning every now and then, whether it be a gentle pruning to redirect growth or a more severe pruning to revive growth. What isn't so obvious is when the best pruning should be done. The simple answer: It depends on the grape variety. There are flowering vines and leafy vines as well as annual and perennial vines.

Although most vines grow vigorously and forgive cutting errors, correct pruning is particularly important for flowering vines in order not to endanger next year's flowering. Here's what you need to know about pruning grape vines.

Leafy vines vs. flowering vines

Deciduous vines, grown for their foliage, can be cut back virtually any time during the growing season. The same goes for removing dead, diseased, infected or damaged stems, regardless of the grape variety. And of course, there's no better time than now to cut back any stray or unruly shoots that pose a nuisance or safety risk.

With flowering vines, timing becomes much more important. An easy way to know when to prune is to consider the flowering time. Vines that bloom early in the season – before summer – do so at the previous year's growth level (old wood). Prune these vines immediately after flowering. This ensures that the vine has time to develop new flower buds for the next year. Examples include wisteria, acebia, jasmine and spring-blooming clematis.

Vines that bloom later in the season – in summer or fall – display flowers on the current year's growth (new wood). They can be pruned in late winter or early spring as there is still time for new shoots to develop and new flower buds to form. It is best to prune the plant before the buds swell, generally in late winter in the south and early spring in the north. Examples of summer-flowering vines include honeysuckle vine, trumpet vine and passionflower.

Prune vines that can become a nuisance from self-seeding, such as: B. the black-eyed Susan, back before the seeds form.

Annual vines vs. woody vines

Annual vines sprout from seeds, grow, flower and go to seed – all in the same growing season. In mild climates where winter cold may not kill an annual vine, it should be cut back in the fall after a cold snap has killed the top growth. In cold climates, the only pruning required is to train stems to grow in the desired direction or to cut back unwanted shoots during the growing season.

Woody vines are naturally perennial and will come back year after year if grown in the correct hardiness zone. With the exception of spring-flowering vines, it is best to prune woody vines in late winter to early spring before new growth begins. At this point the structure is easier to see, so it is a good time to thin out overly woody old growth and trunks that show damage from winter cold, insects or disease.

When pruning woody vines, be sure to remove any shoots that appear at the base, especially on grafted vines such as climbing roses, so that top growth remains true to the variety. Some woody vines can be trimmed drastically to keep their size under control (although of course it's a better idea to plant vines that won't outgrow their space). Examples include vigorous wisteria and trumpet vines. Carry out this renewal pruning in late winter or early spring.

What to prune

In addition to removing dead, diseased and damaged stems, remove knotted, unruly or weak and underperforming stems. Also cut out unwanted shoots that spoil the appearance of a vine. When removing diseased trunks, cut them back to healthy wood. Take the extra precaution of disinfecting pruning blades with a 10 percent bleach solution between cuts to prevent the spread of disease.

Container-grown vines fresh from the garden center rarely need pruning at the time of planting. However, it is recommended to shorten long, spindle-shaped shoots by up to a quarter to encourage new, thicker growth. In subsequent years, cut back overly aggressive shoots to balance a vine's growth habit.

When pruning vines, do not leave stubs; Instead, cut about ¼ inch away from a bud facing the direction you want the vine to grow.