How Snow and Rain Affect Aromatic Plants

How snow and rain affect aromatic plants is not often discussed but is a vital process in the cycle of aromatic plant life. By herbalist and aromatherapist Sharon Falsetto Chapman.

Winter snow and rain are a vital part of a plant’s ecological survival story in many parts of the world. However, as climate changes begin to affect our seasons, how might that affect a plant’s winter cycle?

In this article, we’ll take a look at the role of winter snow and rain for plants and the importance of its role in a plant’s life.

The Aroma of Winter in the Landscape

In the northern hemisphere, we associate winter with the aromas of evergreens, firs, and tree aromas – probably because these plants are not dormant and their oils are one of the few aromas we pick up from the landscape. Tree aromas vary, but can be calming, cleansing, or stimulating, depending upon the tree species.

Snow and ice traditionally cover many northern winter landscapes, but a lot of plants survive these harsh winter conditions and produce new growth in the spring. Winter is the hardest season for a plant’s survival; plants need water to live and in winter the soil is often frozen with ice and snow, trapping any water within it. The plant can not replace any water losses and as a result, the plant will die. Plants and trees have adapted various ways in which to survive the traditional winter.

What Happens to Aromatic Plants in Winter?

Aromatic annual plants do not the survive winter and flower for only one growing season. New seeds have to be planted in the spring to produce the next year’s growth and harvest. Aromatic annual species include sunflower (Helanthius annuus), German chamomile (Matricaria recutica) and basil (Ocimum basilicum). Perennial plants do survive the winter but “hibernate” under ground. The growth above ground dies at the end of the growing season but the roots of the plant are protected by snow, which acts as insulation; new growth traditionally follows in the spring. Aromatic perennial plants include sage (Salvia officinalis), oregano (Origanum vulgare) and rosemary (Salvia rosmarinus). 

Deciduous trees effectively become dormant throughout the winter months as well. They drop their leaves in the Fall and as a result do not need to photosynthesize and need little water. The tree has received enough nutrients through photosynthesis in the spring and summer months to maintain it throughout the winter, once its leaves have fallen.

Evergreen plants or coniferous trees, such as pine (Pinus sylvestris), fir (Abies balsamea), and Douglas fir (Pseudotsuga menziesii), do not lose their leaves in winter. Cypress (Cupressus sempervirens) and juniper (Juniperus communis) also fall into this category.

The needles of evergreen trees hold little water; the needles primarily contain sugars, alkaloids and non-freezing essential oils (which is why we smell their aromas during this time). The needles of the evergreen tree evolved from leaves to minimize water loss and ensure the tree’s survival throughout the winter. Evergreens are slow to photosynthesize and can maintain functions in lower temperatures than other plants.

How Do Snow and Rain Affect Aromatic Plants in Winter?

Snow and winter rain is vital to the winter survival of plants and trees. Snow acts as an insulator and protects the plant from harsh, winter conditions. Snow flakes have a unique structure; they have small intervening spaces within their structure which are filled with air. This means there is low heat conductivity; as a result, the daily temperature penetration into the snow is minimal and plants are protected from frost and freezing conditions. Freezing temperatures also help to conserve plant matter which has died back and returned carbon to the soil. Soil health is the number one component to having a successful garden. Once the snow melts, the moisture is also good for the plants.

The Effect of Changing Weather Patterns on Plants

In some areas of the world snowfall is reducing; in other areas of the world snowfall is occurring earlier in the season than it has traditionally occurred. A 2007 UNEP report Global Outlook for Snow and Ice stated that in the northern hemisphere snowfall had reduced by seven to ten per cent over the last forty years for the months of March and April. Throughout the northern hemisphere, the period of the year when there is no snow cover has also lengthened.

If snowfalls occur early in the winter season, or even at the end of Fall, some plants may traditionally be unprepared for the sudden climate change which may result in the plant dying; however, should snowfall be later or lighter in the traditional winter months, plants may struggle to survive too.

The Future for Aromatic Plants

Each time we reach to use a bottle of essential oil or another aromatic substance, we are using a precious and valuable resource. If weather patterns continue to change, plants may become stressed, confused, and struggle to survive. It is for this reason, we have started growing our our herbal garden here at Sedona Aromatics in order to study aromatic plants further, distill our own oils and waters, and learn how we can adapt to help certain aromatic species survive changing weather patterns.

The Study of Aromatic Plants in Aromatherapy

To learn more about how aromatic plants are used in aromatherapy practice, consider joining us either in the Botanical Aromatherapy Membership School or in our Language of Aromatics certification program!

References:

• Global Outlook for Snow and Ice, accessed from: https://onlinelibrary.wiley.com/doi/full/10.1111/j.1751-8369.2008.00046.x  (Original report no longer freely available online)

• University of Illinois website, How Does Winter Help the Garden?, accessed from: https://extension.illinois.edu/blogs/good-growing/2021-02-18-how-does-winter-help-garden#:~:text=Snow%20will%20melt%20eventually%20and,should%20be%20ready%20for%20planting.   

• The author of this article has a 20 year history in the health care and aromatherapy industry. She is UK-certified aromatherapist and a NAHA Certified Professional Aromatherapist (R). She is both a published author and editor in aromatherapy, a herbalist, and formulator. She is the author of Authentic Aromatherapy and the current chief editor of the NAHA Aromatherapy Journal. She has taken the online Master Gardener short course series with the University of Oregon and studied extensively with the Chestnut School of Herbal Medicine. Sharon works from her garden studio in Sedona, Arizona, surrounded by aromatic gardens and native flora and fauna.