When to Trim Hedges
Knowing when to trim your hedges is of utmost importance if you want healthy shrubs in your garden. It can be the difference between a collection of scraggy plants and an effective green fence guarding your privacy. Whatever the purpose of your hedges, they are sure to need special care. This depends on their type:
Deciduous hedges
Deciduous woody plants typically have two growth spurts every year. The main one is during spring, and then in summer comes a smaller one. The optimal time to trim if you want to keep your hedges tidy is after each one of these. Any major pruning should be done when the plant is dormant. Also hedges should never be trimmed when the weather is dry.
Evergreen hedges
Evergreen hedging plants are typically very vigorous, which thrive on biannual pruning. However if you wish to make them denser you can increase the number of trims. When you trim in late spring or the beginning of summer you should target the new growth. It’s easier to cut with shear or a powered tool. Alternatively you could also trim these in summer. This will give you a looser more woody hedge, that may require more trimming time and the use of secateurs.
Some more specific pruning advice for the most popular hedges in Australia:
Lilly Pilly should be trimmed in late winter or early spring, as soon as the last frost is gone and before the bout of spring growth.
Photinia is pretty much the same as Lilly Pilly, but mind that it has a tendency to grow dense which restricts it’s further growth as the foliage impedes airflow and sunlight access of the middle. If that is the case with your shrubs it’s best to trim them in late spring after the growth spurt.
Boxwood also follows this principle, but keep in mind that it prefers to be trimmed on cloudy days, to prevent the freshly cut leaves and branches from being burned. A sharp tool is also required to minimize damage.
Viburnum requires pruning rarely. Light trimming can be done throughout the year as needed, but heavy pruning and shearing should be left for early spring. It doesn’t need to be done annually as it done for shaping purposes mostly and it isn’t required for a healthy plant unless it’s overgrown.
Murraya is very similar to Box with the added benefits of the pleasant scent of it’s flowers and being able to be kept taller. Spring and autumn is the best times to prune them. If you want to keep their flowers, prune only from the top.
Forsythia flowers in spring, but is best pruned in early summer. This ensures the shrub has enough matured wood to support the blossom next season.