Ever wonder why some herbs in the garden grow really well but others grow dismally? It may be where the herbs are placed.

Herbs can be finicky (to give them a human characteristic) about nearby plants. Scientifically, difference in growth may be the volatile organic compounds (VOCs) herbs synthesize and emit that make some benefactors and others culprits.

Last week’s column discussed the VOCs of the herb basil that makes it a good companion plant for tomato in the garden.

Readers of the June 26 column asked for more information about herbs as companion plants in the garden and it is with those requests in mind that today’s column looks at some herbs that make good companions for each other.

As a refresher, herbs manufacture unique aromatic profiles that are released into the air as volatile compounds. In the micro-world of plants aromatic emissions have a major role in a detracting insects, attracting pollinators, and communicating plant-to-plant. Humans sense plant VOCs as aromas and flavors.

It is the complex plant-to-plant interactions of essential chemical constituents of plants and the volatiles they emit that is taken advantage of in the gardening strategy of companion planting.

Companion herb pairings

Pair similar-needs herbs: those with similar cultural management like well-drained alkaline or acidic soils, high or low moisture requirements, full sun or shade tolerant, and are or are not heat tolerant. Consider growth habits, pairing perennials with perennials and annuals with annuals; take into account if foliage is complementary in color and texture, knowing the mature size for spacing and if mounding or spreading in form.

Following are some herb pairings in the Lamiaceae (mint) family that are mutually beneficial when grown in close proximity. The herb pairs have similar cultural requirements, similar growth habits, complementary volatile aromatic compounds with similar chemical composition and essential oils.

One of dozens herb pairings with divergent yet complementary compounds:

Sage (Salvia officinalis) Rosemary (Salvia rosmarinus)

Rosemary is one of the best garden companions to pair with sage. Both require similar cultural conditions of full sun, well-draining soil and are heat tolerant; fragrant foliage emissions are unique but complementary. Both synthesize some common aromatic compounds like rosmarinic acid but have divergent metabolic pathways; the rosmarinic pathway in rosemary produces carnosic acid among other compounds while the sage rosmarinic pathway makes caffeic acid. Different yet complementary.

Other Lamiaceae pairings:

Lavender (Lavandula officinalis ) and Rosemary

Thyme (Thymus vulgaris) and Sage

Lavender and Sage

Thyme and Rosemary

Some information from ncbi.nlm.nih.gov

 Ellen Peffley taught horticulture at the college level for 28 years, 25 of those at Texas Tech, during which time she developed two onion varieties. She is now the sole proprietor of From the Garden, a market garden farmette. You can email her at gardens@suddenlink.net

This article originally appeared on Lubbock Avalanche-Journal: Gardening for You: Herbs can complement each other