How to Trim Excess Growth on Herb Plants

Knowing when to prune herbs can have a great effect on the size of the plants and the flavors and aromas produced. Cutting back herbs at the wrong time of the year or by too much can kill the plants. There are a few crucial steps to keep in mind to ensure that your herb garden stays robust and healthy. Here's how to successfully trim excess growth on herb plants.

Difficulty: Moderately Easy

Instructions

1. Pull out excess seedlings when too many sprout very close together. Follow the spacing guidelines for the type of herb.

2. Deadhead annual herbs such as basil and mint. Deadheading involves clipping off flower buds before they bloom. Deadheading helps these herbs to develop their best aromas and flavors.

3. Resist trimming or deadheading herbs that are raised for their seed, like caraway and coriander.

4. Cut back herb foliage whenever you transplant the plant. It will reduce transpiration and stress on the roots. This is a good time to harvest the herb to be frozen, dried or used fresh as immediate harvesting can reduce the shock of transplanting.

5. Prune excess growth on herb plants that are very close together to keep air circulating around each plant. Simply trim the ends off with shears.

6. Harvest herb leaves and flowers in the morning after the dew has dried but before the sun burns off the essential oils.

7. Cut back perennials in February. Remove old, scraggly growth to make way for new spring growth.

8. Prune soft perennials such as germander and oregano by 50% during the rainy season.

9. Leave at least 2/3 of the growth behind on perennial herbs to avoid weakening the plants. Annuals can be cut down to the ground.

10. Prune thyme back in the fall to keep the growth from becoming too woody the following spring.