When winter begins, gardeners everywhere plant pansies. These early annuals are beloved for their tolerance of cold temperatures and big, brightly colored blooms with their characteristic blotch. Pansies are also planted in autumn, bringing late color to the garden through winter months or even overwintered to bloom again in early spring.
How much cold these garden favorites will survive depends on your specific climate and growing conditions.
Find out how much cold is too cold, how to protect your pansies from snow and freezing temperatures, and ways to revive them when winter weather leaves them looking puny.
Some pansy varieties are known as Ice or Winter pansies and are set out in autumn. Winter pansies bloom throughout autumn, winter, and spring in warmer climates and in early spring in colder climates.
Pansies are a popular cool weather flower known for their cheerful faces and vibrant colors, But just how much freezing cold can these hardy plants endure before succumbing to winterkill? Understanding pansy cold tolerance helps gardeners provide the right conditions for overwintering these flowers even in frigid climates
The Basics of Pansy Cold Hardiness
Pansies belong to the Viola genus which contains small, low-growing flowers native to temperate parts of Europe and Asia. This means pansies evolved natural tolerances for surviving freezing winters in their native habitats. Key facts about their cold hardiness include:
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Pansies thrive best in cool conditions ranging from 40°F to 60°F Temperatures consistently above 80°F can cause flowering to cease
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Most standard garden pansy varieties can tolerate freezing temperatures down to around 20°F to 25°F when established Brief drops below this point are usually fine
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Extra-hardy winter pansy cultivars can withstand even lower temperatures nearing 0°F when fully dormant.
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Young pansy seedlings, new fall transplants, and actively growing plants are less cold tolerant.
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Freezing weather often causes pansy leaves to shrivel and turn grayish-green but plants frequently revive when warmer weather returns.
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Prolonged deep freezes below 10°F may kill pansies, especially without an insulating layer of snow cover.
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Pansies growing in pots above ground are more prone to root damage from severe freezes.
With proper selection and care, pansies can brighten gardens even in zones with frigid winters during late fall, winter, and early spring.
Choosing the Most Cold-Hardy Pansy Varieties
Some modern pansy varieties have been selectively bred to withstand even lower winter temperatures. Look for these extra-tough cultivars able to handle freezing nearing -20°F and colder:
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Nordic Series – Hardy to 0°F, some varieties down to -20°F.
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Alliance Series – Withstands freezing to -10°F.
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Babyface Series – Tolerates temperatures down to -15°F.
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Majestic Giant II Series – Hardy to -10°F.
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Delta Premium – Survives freezing down to -20°F.
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Matrix Series – Specifically bred for early spring planting, resists -30°F.
Selecting the most cold-tolerant pansy varieties available helps push their limits for overwintering success. Check plant tags for zone ratings to compare cold hardiness.
Providing Ideal Winter Conditions
To help pansies survive frigid winter conditions, it’s important to provide:
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A sheltered garden location protected from sweeping winter winds and with a southern exposure to maximize weak winter sunlight.
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Raised garden beds that promote drainage away from the roots in heavy clay soils prone to freezing.
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A 2-4 inch layer of mulch like pine straw or wood chips over the soil to insulate roots from deep freezes. Avoid piling mulch directly on the plants’ crowns.
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Late fall fertilizing with a balanced flower fertilizer to strengthen plants before cold dormancy sets in.
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Good air circulation around plants to minimize foliar fungal and bacterial diseases in cool damp weather.
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Delaying initial planting until fall nighttime temperatures consistently stay above 28°F to avoid shock.
Meeting pansies’ basic cultural needs gives them the best advantage when challenging cold weather arrives.
Protecting Pansies During Extreme Lows
When extremely icy, sub-zero weather is forecast, these tactics can further safeguard garden pansies:
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Covering beds temporarily with insulating fabric row cover, cloches, or low tunnels – ventilate on sunny days.
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Adding extra mulch over beds before cold snaps, leaving plants’ top growth uncovered.
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Moving containers together in a protected area and wrapping or covering with burlap, straw, or insulation.
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Loosely wrapping foliage with breathable material like row cover to shield from desiccating winter winds.
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Mounding pansies with evergreen branches to provide natural insulation.
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Watering beds thoroughly before forecasted hard freezes to keep roots hydrated.
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Delaying any heavy pruning until new spring growth emerges.
Temporary protective measures reduce risk of severe cold damage when temperatures dive well below the optimal range for pansies.
Signs of Cold Injury
Watch for these warning signs that freezing temperatures have taken a toll on pansies:
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Leaves shriveling and turning limp, grayish-green or purplish-black.
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Delayed emergence of new leaves and flowers in spring.
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Sudden collapse of flowering after cold snaps.
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Noticeable decline in plant vigor, reduced spread or stunted growth.
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Wilting and drooping even in moist soil.
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Stem damage like splitting of tissues.
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Eventual crown collapse indicating significant loss of roots.
While concerning, cold damage does not necessarily mean certain death. Resilient pansies often recover reasonably well when warmer weather returns if the crown stayed protected. However, repeated exposure to temperatures below 10°F greatly increases risks of mortality. Preventing freeze injury through proper care is far more effective than attempting to rescue pansies damaged by sub-zero temperatures.
Avoiding Common Winterkill Issues
Here are missteps that make pansies more prone to serious cold damage and winterkill:
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Failing to select the most cold-hardy varieties available.
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Planting too late in fall after cold weather has already arrived.
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Exposing plants to relentless winter winds and poor air circulation.
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Allowing soil to stay saturated in winter leading to root rot.
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Neglecting to apply mulch in fall to insulate soil.
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Not providing temporary covers during extreme sub-zero cold snaps.
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Fertilizing excessively right before winter dormancy sets in.
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Severely pruning back plants in late fall.
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Siting beds in low spots with poor drainage.
Giving pansies every advantage helps them withstand challenging winter conditions.
Enjoying Pansies Through Winter
With thoughtful care, preparation, and protection, gardeners can continue growing pansies in many cold winter regions from fall through spring. The keys are selecting the hardiest varieties, providing ideal growing conditions, and insulating plants when bitter sub-zero weather threatens. While winter freezes cause temporary setbacks, resilient pansies rebound to deliver their cheerful flowers again. With proper diligence, gardeners can harness pansies’ cold tolerance to brighten the dreary winter landscape.
How Do You Prepare Pansies for Cold Temperatures
Pansies grow best in soil temperatures ranging from 45 to 65 degrees F. Ideal air temperature ranges from 40°F at night to 60°F during the day. For bedding plants, choose a southeast location that receives plenty of morning sun. Cold overnight temperatures may cause plants to droop but warmth from winter sun perks them up again.
Buildings, stone walls, and foundation shrubs protect from cold, desiccating winds. Move potted plants into a garage, porch, or other sheltered location when heavy frost or an extended freeze is forecast.
A thick layer of straw mulch retains moisture to help roots sustain cold soil. Insulating row covers prevent foliage and blooms from freezing when the mercury drops below 32°F
Will Pansies Come Back After a Freeze?
Pansies grown in southern climates are more likely to survive an occasional freeze and even bounce back when covered with snow. Cold air is less likely to cause dieback than extended periods of frozen ground. Winter pansies can sometimes revive even when frozen solid.
Frozen soil affects the roots ability to take up water and nutrients. When starved too long plants eventually die. Pansies are better able than most annuals to withstand these adverse conditions and once temperatures warm a bit and plants receive sufficient sun, they begin to form new buds.
Whether planted in autumn or in early spring, pansies are grown as annuals and replanted every year. Some spring-planted types rebloom in autumn once temperatures drop into the 60°F range during the day with cooler nights. In climates where the ground doesnt freeze, autumn-planted pansies often last through until early summer of the following year when they finally succumb to summer heat.
Occasionally a pansy pops up in a flower bed or pot, sometimes a year or two after the original planting. These volunteers lack vigor and are usually short-lived.
Can winter pansies survive frost?
FAQ
What temperature is too cold for pansies?
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Ideal Temperature:Pansies thrive in cool weather, with temperatures between 45°F and 65°F (7°C and 18°C).
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Cold Tolerance:They can tolerate short periods of temperatures below freezing, but prolonged exposure to temperatures below 25°F (or -4°C) can cause damage or death.
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Signs of Cold Damage:Wilting, gray-green foliage, and stunted growth can indicate that pansies are experiencing cold stress.
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Protection:To protect pansies from cold, you can cover them with a frost cloth, bring potted plants indoors, shelter them from the wind, or apply a layer of mulch around the base of the plants.
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Frozen Soil:Frozen soil can prevent pansies from absorbing water, so it’s important to protect the roots from freezing.
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Soil temperature:Pansy roots literally shut down and stop functioning when soil temperatures fall below 45°F.
When should you bring pansies inside?
Pansies aren’t typically on our list of plants to overwinter, however, this can be an option if you feel your conditions are particularly cold. ‘In cases where temperatures plunge below zero, covering pansies with a frost cloth or bringing potted plants indoors overnight can help protect them,’ says Zahid.
Can pansies stay outside now?
Cool-weather tolerance: Pansies are cold-tolerant plants that can withstand light frosts, making them a great choice for extending the gardening season in both spring and fall. This resilience allows you to enjoy their colorful blooms when many other flowers are not yet in bloom or have already faded.