5 plants to prune in August — expert tips for future growth

Having enjoyed a backyard of blooms over the spring and early summer months, it’s time to take stock and grab your best pruning shears again. Although the height of the growing season is nearly over, there are still some plants in August that need pruning to ensure they thrive, and could even see a second bloom if you act now.

“Pruning is essential for maintaining the health and aesthetic of your plants,” explains Nigel Lawton, plant buyer at Dobbies’ . “By removing dead, diseased, or overgrown branches, you can help stimulate healthy growth, improve air circulation, and enhance the flowering or fruiting potential of plants.”

In addition to creating healthy plants, he adds, “Pruning at the right time ensures that plants have ample opportunity to recover and thrive, avoiding unnecessary stress.” We spoke to Lawton to hear the top five plants to prune in August, and how to do it.

1. Wisteria

Wisteria, with its stunning cascades of fragrant flowers suspended on vines, puts on a magnificent display. However, this beautiful plant can quickly become unruly if left untrained and unpruned.

To keep your wisteria in good shape, Lawtons recommends cutting back the long “whippy” shoots of the current year’s growth in August to about five to six leaves from the main stem. “Ensure you don’t cut too close to the main stem to avoid damage,” he adds. “This pruning helps control the plant’s size and encourages the development of flower buds for the next season.”

Top tip
Wisteria needs to be trained with wires or a trellis against a wall or garden structure to help it grow. During its first few years of growth its a good idea to help train your wisteria at the same time it's being pruned.

Planting zone: 5-7

2. Lavender

Lavender grows well in most yards and is a low-maintenance plant that has many benefits. It’s pleasantly aromatic, attracts butterflies and other pollinators to your yard , and you can harvest your lavender to extend its life.

Although lavender is low-maintenance, it still needs to be pruned. As Lawton explains, “Pruning maintains the plant’s shape and promotes bushier growth with more flowers.”

But what’s the best way to prune lavender in August? Lawton recommends trimming back the spent flower stems and removing about an inch of the current year’s growth once it has finished flowering.  But he warns, “Avoid cutting into old wood as this can hinder new growth.”

Top tip
When and how to prune lavender also depends on the variety you grow. French lavender should be pruned slightly differently from English lavender and won’t need pruning in August.

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3. Roses

Roses can be pruned in August to encourage a fresh flush of blooms in fall, so you can continue to enjoy the flowers for longer. Apart from prompting a continuous display of blooms, Lawton also says pruning roses reduces the risk of disease. Removing dead or diseased branches when you prune increases air circulation and decreases the risk of pests and disease while revitalizing the plant.

Lawton advises deadheading the blooms, particularly for repeat-flowering varieties, by cutting back to the first leaf with five leaflets. He also recommends lightly trimming any overgrown areas for shrub roses. When pruning, he says, “Check for and remove any dead or diseased wood to keep the plant healthy.”

4. Fruit trees

August is also a good time to prune fruit trees as it will help promote fruit formation. So if you grow apples, pears, cherries or plums, they will benefit from a prune this month.

Lawton recommends cutting back the current year’s growth to about three leaves above the basal cluster. “Ensure cuts are made just above a bud to promote healthy new growth,” he explains. “This helps control the size of the tree and improves fruit quality by allowing more sunlight and air to reach the fruit.”

Top tip
Although fruit trees can be pruned in August, the main prune should be completed during the dormant season between December and mid-February.

Planting zone: 3-8

5. Hydrangeas

The best time to prune hydrangeas can vary depending on your growing variety. However, macrophylla types, or bigleaf hydrangeas, can be pruned in late summer.

Lawton suggests leaving faded blooms intact to provide frost protection over the winter.  “Removing one or two of the oldest stems each year will promote new growth from the base and help encourage flower growth”, he says.  “Careful pruning helps to promote vigorous growth and ensures a beautiful display of blooms next year.”

Top tip
Macrophylla hydrangeas bloom on last year’s wood and new wood that grows during the current year. Therefore, the plant will bloom whether it is pruned or not.

Planting zone: 3 to 9

More from Tom's Guide

• Discover 7 pruning mistakes you never knew you were making
• And five ways to get the best out of your pruning shears
• Plus, 5 hydrangea pruning mistakes to avoid