Lavenders are gorgeous purple plants which can add colour to the garden for several months.

They also smell beautiful and help deter a number of pests thanks to their strong scent.

The plants can last for several years as long as they are pruned, but there is an art to pruning lavenders correctly.

In his latest blog post, Monty wrote: “To avoid woody, leggy plants, lavender should be pruned every year.

“The best time to do this is as soon as the flowers start to fade, which, depending on the variety, can be any time between mid-summer and the end of September.

“But do not wait for the seed heads to turn brown as you want to allow the maximum amount of time for regrowth before winter.

“Cut back hard to a good compact shape but be sure to leave some new shoots on each stem.”

This is because lavender will often not regrow from bare wood, according to the gardening expert.

The pro added: “These new shoots will grow fast and provide an attractive and healthy cover to protect the plant in winter and provide the basis for next year’s display.”

To look after lavender in winter, move them to a more sheltered location such as a greenhouse, cold frame or by a wall.

If you live in an extremely cold climate, it is recommended to cover the plant with a breathable fabric for extra warmth.

Pruning roses is also a great job to do in September, but in particular shrub roses, according to Monty.

He wrote: “Do not worry about the position or angle of the cuts but clip away all long, straggly shoots as though were trimming a hedge, leave compact, slightly domed bush that is about two-thirds of its former size.”

In March, when there is no foliage, inspect the shrub to remove any damaged or rubbing stems, but a simple shear in September is usually enough.