Cold Hardy Herbs – Growing Herbs That Survive Winter
Cold hardiness refers to plants’ ability to withstand extreme cold conditions. The term was first used in 1847 by the botanist Joseph Priestley (1788–1859) when he described how some species of plants could survive freezing temperatures. Today, it’s widely accepted that most plant species are able to tolerate at least -30°C (-4°F).
The main factors affecting whether or not a plant will survive freezing temperatures include its growth habit, water content, root system size and other environmental factors. Plants grown under these conditions tend to retain their vitality longer than those grown in warmer climates. Some plants have evolved special mechanisms to keep them alive even if they’re exposed to extremely low temperatures. These mechanisms include photosynthesis, which converts sunlight into energy; respiration, which uses oxygen from the air to produce food and carbon dioxide gas; and the production of vitamins A, C and E.
Herb seeds are very sensitive to changes in temperature. They don’t germinate until they reach around -25°C (-3°F), but once they do sprout, they may not survive long enough to become adults.
Most herbs grow in the spring and summer when temperatures are warmest. At these times, they require plentiful amounts of water, fertile soil and at least six to eight hours of direct sunlight each day. After a few months, they produce flowers and seeds. Then, as the days get shorter and the temperatures start to drop, herbs go into a state of dormancy and stop growing altogether. Some species, such as lavender (Lavandula spp.), will grow again when the temperatures rise in the spring.
Herbs that grow in extremely cold conditions have adapted various survival mechanisms to help them endure extreme weather fluctuations. As long as these mechanisms are in place, the majority of herbs will continue to grow and produce their unique foliage and flowers regardless of light, water and temperature levels.
One of the most important factors is the herb’s root system. The larger the root system, the more stable the plant will be and the better able it will be to access water and nutrients. Maintaining a good balance of water, nutrients and oxygen in the soil is vital for growth. Herbs have a C3 carbon fixation process, which converts carbon dioxide into organic compounds. This is accomplished through the production of cellulose and other plant fibers, which are essential for plant structure and cell growth.
Cold hardy herbs grow naturally in very harsh climates with extreme fluctuations in temperature. They are accustomed to drought conditions and grow well in poor, sandy or rocky soils. These herbs have adapted to their environments by undergoing photosynthesis at higher rates, especially when exposed to sunlight.
Some herbs have natural pest deterrent properties, which protect them from getting eaten by wildlife. These include growing higher than the reach of most animals, having a bitter taste or smelling bad. Other herbs have adapted to grow in salty soils and can tolerate salt on their leaves.
In many traditional first-aid remedies, such as herbal poultices and salves, herbs with astringent properties are used to promote healing. An astringent herb has the ability to contract soft tissue, which reduces bleeding, helps to slow bacterial growth and shrinks the area of the wound.
Herbal extracts have healing benefits as well. They can be applied directly to the skin to disinfect an infected wound, or taken internally as a mouthwash or throat spray to alleviate pain and swelling.
Herbal tinctures are made with high-proof alcohol to preserve the herbs’ antioxidants and healing elements. These can be taken internally or applied directly to the skin as a disinfectant.
The fresh leaves of an herb can be rolled into a cigarette and smoked, or chewed slowly to alleviate respiratory irritation, clear phlegm and reduce pain caused by swelling in the throat and lungs.
Herbal smoke blends are a combination of dried or fresh herbs that have been specially mixed together for the purpose of smoking them. Many contain healing elements and help alleviate the symptoms of asthma, bronchitis and other respiratory conditions.
Herbal infusions may be applied topically as a soothing salve for skin irritations and allergic reactions, or used as a mouth rinse to reduce swelling in the mouth and throat.
Herbal ointments are made with a combination of herbs, oils and beeswax to soothe the skin. They can be applied topically to alleviate itching, burning, pain and swelling, especially in areas affected by skin conditions such as rashes, hives, herpes, acne and eczema.
When choosing an herbal remedy for your first-aid kit, ensure that it comes from a reputable manufacturer that you trust. Quality should always come before cost, as herbs with fewer healing properties can actually cause harm if used when dealing with an injury.
The next time you are out hiking, make sure to keep your first-aid kit stocked with a few extra natural remedies for minor cuts, scrapes and burns. For more serious injuries, ensure that you locate the emergency number in your area (usually 911) and make use of modern first-aid techniques until medical attention arrives.
Herbalism is the practice of using plants and plant materials for health and healing.
Dandelion (Taraxacum officinale) has edible leaves and yellow flowers, and has been used in herbal remedies for centuries. It is used to reduce swelling, enhance liver function and help the body eliminate excess fluids.
Dandelion can be steeped as a tea or applied topically to soothe the skin and speed the healing of minor cuts and burns
Plantain (Plantago major) grows throughout the world in various climates. Its broad leaves have traditionally been used for healing cuts, bites and stings. It has astringent properties and can be chewed into a poultice, or steeped as a tea and applied topically to minor cuts, burns and skin irritations.
Herbal Healing Ointment
Cayenne (Capsicum annuum) is a red chili pepper that grows throughout tropical regions worldwide. It has a spicy hot taste and contains various nutrients that promote circulation and provide natural pain relief.
Cayenne can be used to make a topical ointment that reduces swelling, relieves pain and speeds the healing of bruises, sprains, strains, sore muscles and joints.
Sources & references used in this article:
Variation in snow cover drives differences in frost resistance in seedlings of the alpine herb Aciphylla glacialis by VF Briceño, D Harris-Pascal, AB Nicotra… – Environmental and …, 2014 – Elsevier
Constraints of cold and shade on the phenology of spring ephemeral herb species by CK Augspurger, CF Salk – Journal of Ecology, 2017 – Wiley Online Library
Frost survival of plants: responses and adaptation to freezing stress by A Sakai, W Larcher – 2012 – books.google.com
Stolon characteristics related to winter survival in white clover by RP Collins, I Rhodes – The Journal of Agricultural Science, 1995 – cambridge.org
The ecology of arctic and alpine plants by WD Billings, HA Mooney – Biological reviews, 1968 – Wiley Online Library
Adaptation of pulse crops to the changing climate of the Northern Great Plains by HW Cutforth, SM McGinn, KE McPhee… – Agronomy …, 2007 – Wiley Online Library
An explanation for alpine timberline by P Wardle – New Zealand journal of botany, 1971 – Taylor & Francis