How to Grow Oregano: A Toronto Master Gardeners Guide

Oregano (Origanum vulgare var. hirtum). Oregano, the so-called “pizza herb,” is closely related to sweet marjoram (Origanum majorana). For the best flavour, seek out Greek oregano (Origanum vulgare var. hirtum) from a reputable grower or seed supplier. Avoid common oregano (Oregano vulgare) as it lacks true ‘oregano’ flavour.

Cultivation: Oregano is a loose, open plant growing from 15 to 60 centimetres tall with gray-green leaves and small white flowers. Although oregano is hardy to Zone 5, it is generally grown as an annual or in a pot for overwintering indoors. True to its Mediterranean origins, oregano thrives in hot sun and, once established, it can tolerate dry conditions. It may overwinter outdoors in Toronto if given a cover of evergreen branches or straw in early winter.

Oregano is generally propagated from cuttings. Plants are often mis-labeled so when purchasing, you may wish to smell the leaves before you buy! Once danger of frost is past, plant oregano in the garden in full sun or part shade with well-drained soil, or in a pot with very good drainage. The leaves of plants grown in shadier conditions may have a less pungent flavour.

Harvest leaves just before the plants are ready to flower by removing stem tips, ensuring that four to six pairs of leaves remain on the stem. Side shoots will then grow, producing a bushier plant. This process can continue through the season as long as the plant continues growing. Once the plant has flowered, growth may slow and the flavour of the leaves is less intense.

Disclaimer: Toronto Master Gardeners does not advise or recommend herbs for medicinal or health use. Any information in the recommended resources should be regarded as being for educational purposes only and should not be considered as a recommendation or an endorsement of any medical or health treatment.

For more information:

Herb Society of America Quick Facts Oregano https://www.herbsociety.org/file_download/inline/f411e1df-378f-4fcb-aa62-9179f0151c84

OMAFRA http://www.omafra.gov.on.ca/CropOp/en/herbs/culinary/orega.html

Richters https://www.richters.com/show.cgi?page=MagazineRack/Articles/oregano.html

RHS Grow your Own Herbs: Oregano https://www.rhs.org.uk/advice/grow-your-own/herbs/oregano

University of Illinois Extension https://web.extension.illinois.edu/herbs/oregano.cfm

Date revised: December 2021

Prepared by the Toronto Master Gardeners, these Gardening Guides provide introductory information on a variety of gardening topics.  Toronto Master Gardeners are part of a large, international volunteer community committed to providing the public with horticultural information, education and inspiration.  Our goal is to help Toronto residents use safe, effective, proven and sustainable horticultural practices to create gardens, landscapes and communities that are both vibrant and healthy.

Statement on Invasive Plants: When choosing plants, avoid invasive plants, which can spread quickly and dominate gardens.  Invasive plants are sold by nurseries, big box stores or even at community plant sales.  Invasives may already be present in your garden.  They can invade gardens by spreading from under a neighbour’s fence or may be transported by wildlife.  For beautiful, sustainable options to invasive plants, see the Ontario Invasive Plant Council’s “Grow Me Instead – Beautiful Non-Invasive Plants for your Garden” at https://www.ontarioinvasiveplants.ca/resources/grow-me-instead/before purchasing or accepting “gifts” of plants.

Statement on Home Remedies: The Toronto Master Gardeners do not recommend home remedies, as these have not been proven effective through scientific investigation, and may even damage other living organisms in the soil or plants in your garden.  There are other garden friendly options you can use.

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