Jane Atkinson from Redwing Herb Farm presented this week’s “Ask a Master Gardener” topic: Growing Medicinal Herbs. Jane and her business partner, Kathleen Moritz, have recently established their farm on Howe Island, where they grow various herbs for health, and provide educational workshops to the public.
Benefits of growing medicinal herbs
There are many benefits to growing medicinal herbs; some of the plants used may already be found in your own garden. These plants, like others, provide benefits not only to the grower, but to the land and the pollinators that live there. In growing medicinals, the gardener may acquire a deeper knowledge of the plants, and have easy access to these herbs throughout the season.
The field of herbal medicine is extensive and complex, so Jane choose to highlight just four plants as examples: yarrow, calendula, marshmallow and anise hyssop. Some of these, as well as many others, have long been used by indigenous peoples of various regions. These examples give a small window into the complex medicine and character of the plant, and serve as a quick introduction.
Yarrow (Achillea millefolium) is a member of the sunflower family. This native likes full sun and prefers rich well drained soils, but will also thrive in poorer soils. As many gardeners will know, it spreads easily – to avoid this, it can also be grown in containers. It is drought tolerant, provides nectar for various species of butterflies, and attracts beneficial insects such as ladybugs to the garden. As a medicinal, it is used to treat cold and flu, poor circulation and can be used as first aid for bleeding amongst many other things. Only the aerial (aboveground) parts of the plant are used and are prepared in various ways including as a tea, poultice, steam, wash or infused oil.
Calendula (Calendula officinalis) is a non native, easy to grow annual. It prefers full sun and well drained soil, though will grow just about anywhere! The flowers, which are usually a vibrant orange/yellow, are harvested to be made into various preparations including tea, infused oil or wash. It can be used to promote wound healing, and for digestive tract health. In the garden, Jane also uses this as a “living mulch” and as a trap plant, luring aphids away from other plants.
Marshmallow (Althaea officinalis), not to be confused with Mallow (Malva sp.), is a non native plant found in moist or boggy areas, in full sun to part shade. It is often grown to provide structure and height in the garden, and provides interest with its silvery-green foliage.
The medicinal properties of marshmallow come from mucilage, a sap-like substance found throughout the plant. Jane notes that it is used as an anti-inflammatory and demulcent (soothing and moistening), for example as a topical for skin irritations, or as a wash or cold infusion for other inflammatory disorders.
Anise hyssop (Agastache foeniculum) is a native short lived perennial grown in full sun and well drained soils. The aerial parts of the plant are harvested to make a tea, steam or wash used in the treatment of indigestion, respiratory tract infections or to soothe agitation, amongst many other uses. In the garden, it is a nectar source for pollinators and used for dried or fresh cut flowers.
Jane stressed that it is important to know when it is safe to take any herbal medicines. Be sure of your plant identification, and consult with a knowledgable source (herbalist, pharmacist or doctor) for uses, efficacy and contraindications. Other advice:
- Harvest plants in the morning, after dew has dried, before it gets too hot. Process immediately
- Many medicinal components are secondary metabolites which increase when a plant is under stress, for example, due to low water levels or some pests
- Harvest only what you need and leave the rest for the garden and the pollinators who use them too! Harvest with intention, and consider reciprocity – how can you give back to the soil, plant, land, etc.?
- Dry the harvest by hanging bundles or placing on racks in a warm, dark place with good airflow
Jane’s recommendations for additional resources include the following websites and books:
The Medicinal Herb Grower. Author Rich Cech, Horizon Herbs 2009
Herbal Renaissance: Growing, Using and Understanding Herbs in the Modern World. Author Steven Foster, DIANE Publishing Company 2003