While you may have mastered how to grow rosemary (and how to harvest rosemary for delicious aroma and flavor in cooking or floral displays), it is equally important to know when to begin the pruning process. Though, the time frame is refreshingly generous – stretching across many months of the year.   This is when the experts prune rosemary – for healthy, fragrant shrubs that will continue to look good for longer. 

When to prune rosemary – the time frame you need to know about

‘Rosemary is quite unpretentious when it comes to pruning, so you can do it anytime starting from spring and up until four to six weeks before the first frost hits,’ says  Bryan McKenzie, a garden expert and co-founder of the Bumper Crop Times (opens in new tab).  The expert explains that rosemary is best pruned in warmer weather, as it becomes weaker in cool temperatures. ‘If you choose to prune it during cold seasons, your rosemary bush won’t be able to harden off as its new growth will become too tender and sensitive to temperature,’ he says.  Melody Estes, a Landscape Design Gardening Supervisor from Maine and a consultant at The Project Girl, (opens in new tab) agrees. She, too, urges you to cut in the month before you expect the first frost, and also warns against pruning in wintertime.  ‘Rosemary is a perennial herb that can be grown indoors or out. It’s best to prune rosemary when the plant is in active growth and in full sun. Pruning will encourage new growth, making your plant fuller, bushier, and more attractive,’ she says.

How often should you trim rosemary?

Rosemary needs to be trimmed regularly, especially if you plan on harvesting the leaves or flowers. Melody suggests cutting just before it blooms, but this can depend on whether it’s a bush type or a tree form of rosemary. ‘If you have a bush-type rosemary plant, you should prune the branches back in spring just after they’ve bloomed. This will encourage new growth at the base of the plant and help keep it looking full and healthy throughout the growing season,’ the expert says.  Meanwhile, if you’re working with a bush rosemary plant, it is better to remove any new shoots that appear on older branches – to allow the branches to keep producing flowers and leaves throughout the summer months (or longer). 

Should you cut back rosemary bushes and how much?

Yes, it is best to cut every overgrown rosemary stem to make it the same length as the others. However, the method does come with a warning.   ‘Always avoid pruning the woody parts of the stems,’ Bryan McKenzie, garden expert and co-founder of the Bumper Crop Times says. ‘The logic behind the process is very simple. You cut down fresh growth to let the plant deliver more nutrients for hardening older growth and making it stronger against the environment.’

How do you prune a rosemary plant?

The process behind pruning a rosemary plant is one of the easiest (but most rewarding kitchen garden ideas) you can follow. Firstly, Melody suggests removing all dead wood by cutting the stem at a 45 degree angle so that the cut is clean and there is no jagged edge. She then urges you to cut back any branches growing too far away from the center of the plant.  ‘Cut off any shoots that are growing straight up and down, as they will not produce flowers or buds later on in spring,’ she explains. ‘Prune off any branches that have grown larger than 2 inches in diameter. This helps ensure your plant stays healthy and does not become too large for its space.’