Staying Green in Snow

This article is all about not losing your colour in the cold! This is like a Part 2 to our ‘plant palette’ article in 2023.

Executive Summary by AI -

“The article from Groof.ca, "Staying Green in the Snow," discusses strategies for maintaining greenery during winter, focusing on plant selection for green roofs in cold climates. It highlights various plants capable of surviving harsh Canadian winters while retaining their green foliage, such as Sedum species, Delosperma, Sempervivum, and others. The piece underscores the importance of selecting resilient plants that provide ecological benefits and aesthetic value year-round.”

We’re doing a bit of co-authoring with A.I. the last few articles here, including this one.*

Believe us, the A.I. available today is not yet better than us here at Groof thankfully…

Look around -

What stays green in the snow? Pine trees for sure, but what else?

Don’t forget about indoor plants that survive in winters, indoors (like lemon cypress trees, perfect for indoors or balconies/patios).

We recently did another article about beekeeping opportunities on rooftops, which is a big one in this space we believe. Another important topic in our industry is ‘green roofs in cold climates’ - what’s the right plant palette?

Asking A.I. -

Firstly, we must share with you this lyric from the song “seeing green” by Drake, Nicki Minaj, Lil Wayne, etc. chosen by A.I. to suit this article the best -

From the song "Seeing Green" by Nicki Minaj, Drake, and Lil Wayne, a line that could suit the theme of your article "Staying Green in the Snow" is from Nicki Minaj's verse:

"Ain’t no C in green, but I’m seein’ green." This line speaks to the enduring vitality and resilience of being "green" or flourishing, much like the plants in your article that stay green even in snowy conditions.

Back to the article -

“Plants that stay green even in cold and snowy conditions are often sought after for green roofs, especially in climates like Canada's where winters can be harsh.

Here's a list of plants that are known for their resilience in cold weather and their ability to maintain green foliage”

1. **Sedum Species (Stonecrop)**: Many Sedum species are excellent for green roofs due to their hardiness and low maintenance. They can survive in cold temperatures and retain their foliage.

2. **Delosperma spp. (Ice Plant)**: These are hardy, drought-tolerant plants that can survive cold temperatures. They usually keep their green color throughout the year.

3. **Sempervivum spp. (Hens and Chicks)**: Known for their ability to withstand cold and snowy conditions. They are succulents that retain their leaves year-round.

4. **Festuca spp. (Fescue)**: Some species of Fescue are evergreen and can tolerate cold, snowy conditions, making them suitable for green roofs.

5. **Picea spp. (Spruce)**: Dwarf varieties of spruce can be used on green roofs and they stay green throughout the winter.

6. **Juniperus spp. (Juniper)**: Certain low-growing junipers are hardy and maintain their foliage in cold weather.

7. **Thymus spp. (Thyme)**: Some varieties of thyme are evergreen and can withstand cold temperatures.

8. **Phlox subulata (Creeping Phlox)**: This plant stays evergreen in winter and is suitable for green roofs due to its hardiness.

9. **Iberis sempervirens (Evergreen Candytuft)**: A hardy perennial that maintains its foliage in winter.

10. **Armeria maritima (Sea Thrift or Sea Pink)**: This plant is known for its ability to thrive in tough conditions and remains green in winter.

11. **Campanula spp. (Bellflower)**: Some species are evergreen and can withstand cold temperatures.

12. **Ajuga reptans (Bugleweed)**: Known for its hardiness and evergreen foliage.

“These plants are not only capable of surviving the cold and snowy Canadian winters but also provide year-round visual interest and ecological benefits. It's important to consider the specific conditions of your green roof, such as exposure to sun and wind, drainage, and the depth of the growing medium, when selecting plants. Consulting with a local horticulturist or green roof specialist can provide more tailored recommendations for your specific location and conditions.”

From our 2023 article on ‘plant palette’ -

“
Colder climates

Canadian Landscapes: Plants and Flowers That Survive the Winter | JRL (robertlandscapes.com)

• if you’re a Canadian resident, consider adding gorgeous plants and flowers to your landscape design that survive (and thrive) throughout harsh Canadian winters.
  While some plants can survive winter, others will die.
  Cold-resistant perennials and other plants survive the winter in a resting stage underground.
  Other plants, such as trees and shrubs, are hardy enough to survive the winter above ground.
  

• Here are some of the best flowers that will either grow or survive underground in fall and winter.

• RED TWIG DOGWOOD

• CAMELLIA

• HYSSOP

• CONEFLOWER

• LILY-OF-THE-VALLEY

• SIBERIAN IRIS

• ‘PURRSIAN BLUE’ CATMINT

• CYCLAMEN
  
  Check out these hardy yet beautiful winter plants to find your newest outdoor eye candy.

• WINTERBERRY

• SNOWBERRY

• FIRETHORN

• JAPANESE YEW

• BOXWOOD HEDGE

• ENGLISH BOXWOOD

• SIBERIAN CYPRESS

• HOSTA

• PERENNIALS

• PEONY

• MONARDA
  
  VEGETABLES THAT YOU CAN GROW THROUGH THE WINTER

• Broccoli

• Ornamental Cabbage & Kale

• Collards

• Swiss Chard

• Spinach

• Lettuce

• Potatoes

10 Winter Plants That Will Thrive in the Cold Weather - CNET

• There are actually several plant species you can count on to survive through the winter season.

• Making sure your landscaping is planted with hardy plants is one way to make sure you'll be greeted by greenery after the winter

• Choosing plants that are adapted to your climate isn't difficult and takes just a bit of know-how. There are more than enough plants to choose from and, if you shift all of your landscaping to these perennials, you'll save money and time each year.

• To help people determine that, the US Department of Agriculture has divided North America into distinct areas based on average minimum temperatures called USDA hardiness zones. TL;DR: The lower the number, the colder it's likely to get in that zone.
  

• Local gardeners and nurseries can share firsthand knowledge of what works in your area and what's doomed to fail. A local expert might have a better grasp on microclimates and unique gardening challenges in your area. Temperature isn't the only factor when it comes to healthy plants: soil type, moisture and sunlight all play a role, too.

• Plants that can survive extra-cold winters

• Rhododendrons

• Daffodils, crocuses and tulips

• Hostas

• Bleeding hearts

• Irises

• Daylilies

• Lilacs

• Hydrangea

• Sedum

• Blueberries

  
  While native plants are often pitched as being good for wildlife, including pollinators, they can also be very pretty. Even if you just want a good looking set of flowerbeds, native plants can get you there while weathering winter after winter.

Top 17 Hardy and Cold Tolerant Perennial Flowers - Gardening Channel

• If you live in a colder climate, you probably don’t want to dig around outside, in the cold to add a little color to your yard. But by planting perennials, you can avoid the whole planting process! Plant cold-tolerant perennial flowers once, and they’ll return year after year.

• If you’d like for your yard to brighten up, even while the temperatures are still cold, consider the following flowers as a nice addition for your landscape:

• SIBERIAN IRIS

• YARROW

• NEW ENGLAND ASTER

• LILY OF THE VALLEY

• SEDUM

• CORAL BELLS

• PEONY

• HELIOPSIS

• HOSTA

• BEE BALM

• CONEFLOWER

• BAPTISIA

• WILD COLUMBINE

• LADY’S MANTLE

• BUGLEWEED

• CATMINT

• HOLLYHOCK

Green roofs, cold winters, and dealing with drought - Construction Canada

• Intensive vegetated roof systems are thicker and can support a wider variety of plants, but are heavier and need more maintenance than extensive assemblies, which are covered in a light layer of vegetation. Either way, it is important to ensure the right plants are being used for the project. (Along with the usual roofing concerns, such as waterproofing and structural capabilities.)

• green roofing consultants often suggest selecting the plant material native to the project’s locale. This helps avoid unnecessary plant death by way of establishment and/or if the flora is being transported from far away. Native plant species have also already been adjusted to that particular location’s climatic conditions, making it easier for them to get established quickly.
  

• The plants traditionally chosen for vegetated roofs tend to be hardier species that can be grown almost anywhere; they do not require a specific combination of soil material, with some even thriving out of stones. They also need very little water.
  
  

• While design/construction professionals need not be botanists or horticulturalists, having a background understanding about the subject can be invaluable when working with others to ensure the ideal green roof is being specified. The information shared about the mechanisms of drought and cold adaptations of plants in this article will help engineers and architects designing a green roof understand what type of plants are suitable that are cold-, heat- and drought-tolerant.
  

• The critical knowledge of rain capture and storage plays an important role on plant survivability on a non-irrigated roof as well. This author has been asked frequently by architects about how long the plants on a vegetated roof live. Many times, manufacturers have to provide a survivability certificate on the type of plants being used on a particular roof and their watering requirements, with information if they are drought-tolerant and can survive in heavy rainfall.
  

• For decades, green roofs have been planted with sedums (e.g. Sedum album, S. acre, S. kamtschaticum, S. rupestre, and S. spurium), but there are few publications on the flora’s basic physiology and water use efficiency. Most sedums are Crassulacean Acid Metabolism (CAM) plants, which means they survive through a photosynthesis method that has carbon dioxide (CO2) fixed by an enzyme (i.e. phosphoenolpyruvate carboxylase [PEPC]) during the night to form malic acid that is stored in the plant cell vacuoles, keeping the stomata closed the next day.2 In other words, CAM plants are characterized by their water use efficiency, making them ideal for rooftop environments where they are unlikely to be frequently tended to by a landscaping team.
  
  

• Transferring mature and well-established plants on a roof is more beneficial for survivability than planting young seedlings.
  Lack of research regarding planting options and managing green roof survivability in Canadian climatic conditions means this is a topic not yet widely explored. However, over the last decade, various North American universities are undertaking work to study the suitability of plant species using both native and non-native species for Canada’s colder environment.
  Cold stresses include severely low temperatures, strong winds causing desiccation, ice, and pathogens. Some types of plants adapt to these situations and become tolerant; others remain sensitive and eventually die after a certain exposure period. The most common adaptive feature of cold tolerance or overwintering is cold acclimatization with which plants are able to tolerate freezing injury.15 Cold acclimatization involves a number of molecular changes associated with taking care of the membrane functions at low temperatures.
  
  

• Generally, cold adaptation is defined as plants that survive temperatures as low as −40 C (−40 F) during winter. The freezing of the liquid inside the plants is a serious threat as the freezing of water present in the soil. It causes imbalance in the mechanisms involved in transporting water/nutrients to different parts of the plants.
  
  
  

• When winter is about to set in, it becomes critical to ensure the green roof will not be saturated with water—any excess water should be drained out as it can damage the plants when ice is formed. If this is not taken into account, when the snow melts, plants may not revive completely, leaving patches of dead plants on the otherwise-green roof.
  
  

• This information can be useful to design/construction professionals in regard to pre-winter maintenance. The specifiers can have information available explaining how to protect the plants from getting subjected to freeze-thaw cycles—essentially instructions not to water, remove any excess water, and avoid ponding.
  

• People working for the green roof industry have a huge task ahead of them to understand the effects of cold and drought on the mechanisms of growth and development of sedum plants.
  

• a general knowledge about plants and their mechanisms helps in understanding why a green roof may not be able to establish itself in adverse and harsher climatic conditions.
  

• Although sedums are considered the most tolerant of plants, like any other living species they are subject to limitations after a certain threshold. It is essential now to investigate the undiscovered fundamental principles of drought and cold tolerance of sedums plants. The information is important for the growers mainly to have a clear idea when planting sedums in terms of survivability culminating into better production enhancing yield, which will be economically beneficial in the end.
  

Hardiness Zones in Canada (gardenia.net)

• Canada's plant hardiness map provides insights about what can grow where. It combines information about a variety of climatic conditions across the entire country

These are the 21 best plants for cold weather climates | HappySprout

• The earth is categorized by five different climates. They are tropical, dry, temperate, continental, and polar. The majority of the United States is in dry, temperate, and  continental. A cold-weather climate would be considered continental and would range from zones 1 to 4.

• For inside the home, there are many plants that can survive and even thrive in lower light and shorter day situations. The biggest hurdle with indoor plant care during the winter is moisture.

• Cold tolerant:

  • ZZ plant

  • Snake plant

  • Aglaonema

  • Clivia

  • Jade plant

  • Christmas cactus

  • Succulents and cactus

• Frost resistant:

  • Pines and Evergreens

  • Japanese Yew

  • Blue spruce

  • Browns Yew

  • Cotoneaster

• Bushes and hedges:

  • Boxwood hedge

  • Cypress topiary

  • Thread-Branch cypress

  • Ligustrum

  • English boxwood

  • Winter Jasmine

  • Holly bush

• Trees:

  • Camellias

  • Japanese Maple

  • Star Magnolia

• With a little research, you can find a plant to suit your needs, even if it’s cold outside.

The 15 Best Cold-Weather Plants That Can Withstand Harsh Winter Temps | Hunker

• However, winter is arguably the season when people rely most on nature to provide a reminder that life continues. Plants can survive winter's worst cool weather and thrive, and so will we.

• When you consider adding plants that will survive winter weather, knowing your hardiness zone is of top importance. If you pick plants that thrive in your hardiness zone, they are very likely to survive your normal winter freezing temperatures.

  GROUND COVERS:

• Tricolor Caucasian Stonecrop

• Golden London Pride

• Deadnettle

• Bearberry

• Creeping Dogwood

• SHRUBS

• Winterberry

• Dwarf Alberta Spruce

• Blue Holly

• Limelight Hydrangea
  Japanese Maple

  FLOWERS:

• Peonies

• Alliums

• Hybrid Lenten Rose

• Geranium 'Gernic' SUMMER SKIES

• Coral Bells

60+ Unique Fruits & Nuts for Cold Climates (Zones 3-5) (practicalselfreliance.com)

• The plants listed [in this article] are well suited to grow in zone 3, 4, and 5, providing good yields with minimal effort for a well-planned diverse permaculture homestead. 

Canada's Plant Hardiness Site

• This site explores the relationship between plants and climate across Canada. One portion of the site is dedicated to plant hardiness zone maps, which have traditionally been used by gardeners to help select which plant species to grow in their area. Another part of the site presents maps and models that summarize the climatic requirements of thousands of plants from across North America. A final aspect of the site gathers data and provides summaries about plants that occur in your area.

Best Climate-Hardy Trees for the North - My Northern Garden

• In real estate, the mantra is “Location. Location. Location.” For northern gardeners facing urban conditions and a changing climate, the advice to follow is “Diversity. Diversity. Diversity.” Choosing a variety of trees that can handle salt, weird winters, difficult storm events and new insect predators is the best way to ensure your landscape remains healthy and vibrant.

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