Winter pansies go dormant after temperatures drop to 25°F but will survive to 20°F. These winter plants are cold-hardy, but adding a layer of mulch—sure as light pine straw—over the roots will help the plant retain moisture and reduce damage during a hard freeze.
Pansies and violas are still hardy down into the mid teens, but you'll lose some flowers or flowers buds once you get down into the low 20s or high teens, depending on where they are planted (how exposed versus close to a house or under tree cover).
In general, pansies can be planted in early spring or late summer/early fall.
Pansies are vibrant annual flowers that can handle a frost, lay dormant throughout winter and bloom again in the spring. If planted in the spring, they bloom until air temperatures reach 80-85° F before going dormant and often disappearing from the landscape.
Pansies like full or partial sun, but need cooler temperatures to thrive. The ideal planting site will get morning sun but avoid the heat of the late afternoon. Space the plants about 7 to 12 inches apart. They will spread about 9 to 12 inches and grow to be about 6 to 9 inches tall.
One of the most important factors for success with any plant is the soil. Pansies grow best in light soil full of lots of organic matter. This is extra important when growing them in containers.
If you're wondering when the best time to plant pansies and violas is, you'll want to aim for September and October. Planting in early fall allows these beautiful, hardy flowers to establish themselves before the winter cold sets in.
Pansies experience considerable heat stress at average daily temperatures, or a24-hour average temperature, above 80¡ F; however, pansies can continue tophotosynthesize and grow at mid-day temperatures greater than 90¡ F.
A moderate frost, with temperatures ranging from about 28°F to 32°F, necessitates a bit more precaution. In addition to tucking your plants in well with some frost cloth or cover, it's also a good idea to water your plants the evening before frost is expected to hit.
Freeze Warning - This is issued when there is at least an 80% chance that the temperature will hit 32 degrees Fahrenheit or lower. Light freeze - 29° to 32° Fahrenheit will kill tender plants. Moderate freeze - 25° to 28° Fahrenheit is widely destructive to most vegetation.
Violas are surprisingly hardy plants, and they can tolerate temperatures as low as 0°F with little to no damage.
Epsom salt can deliver great results in gardens that have a magnesium deficiency when used correctly. Roses, tomatoes, peppers, pansies, petunias, and impatiens particularly love Epsom salt, and all need high levels of magnesium for optimal growth.
Heat-loving clematis, daylilies, peonies, sunflowers, and cosmos should be avoided with Pansies. Aquatic and bog plants are also not great companions for Pansies, which require well-draining soil for healthy growth.
Both soil and air temperature affect pansy health. Other growing conditions play a role in determining how much cold they can survive. Air temperature below 25°F for just a few hours can send them into dormancy and below 20°F can cause plants to die back completely.
Set pansy plants in the ground when it becomes workable in the spring. They grow best when soil temperatures are between 45°F and 65°F (7°C and 18°C).
Whether you choose mums and pansies or try your hand with local native flowers, you'll get the best results if you give them Miracle-Gro® Garden Soil for Flowers & Vegetables. Follow spacing and planting directions on the individual plant tags.
Pansies can grow anywhere on the spectrum from part shade (2 to 6 hours of sunlight) to full sun (6+ hours of sunlight). Avoid full shade, since the lack of light can lead to leggy plants and a deficit of blossoms. Ideally, you'll plant them in a spot that receives morning sun and afternoon shade.
They will tolerate crowding. Planning your pansy bed is important. A well laid out design looks stunning when in full bloom. Pansies respond well to regular deadheading.
Overall, even flowers can tolerate light freezes (low 30s to upper 20s °F) and even a little snow. Record cold temperatures (below mid to upper 20s) will damage or destroy many of the flowers of early blooming varieties. The foliage of fully emerged spring-flowering bulbs like tulips and daffodils can also be damaged.