Pansies are one of the prettiest, most appealing bedding flowers you can plant in any garden. Their unmistakable, face-like leaf patterns endear them to just about everyone. Closely related to the viola, they were first cultivated in Europe, but are now grown worldwide.
But the question is, When should we plant pansies? This depends on whether you plant pansy seeds or seedlings that are already established. In many areas, seeds will need to be started indoors. Whether you have germinated your plants or bought established plants from a nursery, plant these in spring.
Planting Pansies in Different Climates
We usually plant pansies early in spring or in the fall. It depends, though, on ground conditions because pansies will grow best when soil temperatures are between 45°F (7°C) and 65°F (18°C).
Soil temperature can have a huge impact on germination. Also, if there is frost this can impact negatively on germination.
Pansies don’t mind very light frost, but they won’t germinate if the ground reaches below freezing at night.
At the same time, pansies prefer cool weather and they tend to get leggy in the summer heat. For this reason, most people treat them like annual flowers.
But, in areas that experience cool summers, short freezes, and moderate temperatures, you can successfully treat them as perennial plants.
The United States Department of Agriculture (USDA) has divided the country into 12 zones based on annual minimum temperatures. Many horticulturists and garden experts use these to guide us when to plant just about anything.
Their plant hardiness zone map is the standard for determining which plants will thrive in a particular location.
However, hardiness to cold weather conditions is only one factor we need to consider. Summer temperatures, rainfall, humidity, and the length of the growing season are also essential factors.
Knowing what kind of climate you live in will help you gauge when you should plant your pansies. We base climate types on categories that were devised by a German climate scientist, Wladimir Köppen in the early 20th century.
Best USDA Zones for Pansies
Most pansy varieties will do well in USDA plant hardiness zones 7-10. Broadly, annual minimum winter temperatures range from 0°F (-17.8°C) in zone 7a to 40°F (4.4°C) in zone 10b.
Anything colder will kill the plants in winter. If it’s hotter than this, they will flower for a short while only.
Some hardy pansy varieties will survive in zone 4-6, where the minimum average winter temperature ranges from a minimum -30°F (-34.4°C) in zone 4a to 0°F (-17.8°C) in zone 6b.
Just remember that these are minimum winter temperatures. The USDA data doesn’t specify summer or maximum temperatures.
Whether you’re guided by information relating to climate types or USDA zones, it can be very confusing. For instance, as the University of Georgia Extension points out in an online publication, Success with Pansies in the Winter Landscape: A Guide for Landscape Professionals, zones 6b-8b feature in the state.
It’s hotter in the south of Georgia than in the north, and this will affect when you plant. The same applies to other states.
The USDA’s Forest Service has a useful interactive map where you can key in your address to find out which zone you live in.
Heat, humidity, and lots of rain typify tropical climates. Temperatures are high, ranging from 64°F (18°C) to 85°F (30°C). There are more than 59 inches of rain every year.
The tropics stretch along and on either side of the equator. The southern tip of Florida is the only true tropical region in the U.S.
Dry climate zones may be as hot as tropical climates, but the weather is very dry and there is not a lot of rain.
Generally, average temperatures don’t dip below 50°F (10°C). In desert regions, you may experience summer highs of 104°F (40°C) and in winter it can drop below freezing.
Most of the dry-climate regions in the U.S. are in the west of the country.
A temperate climate is warm. Winters are mild and summers are humid with thunderstorms bringing rain.
Most of the U.S. temperate regions are in the east, south of Minnesota, Illinois, Indiana, and Ohio. The coldest temperatures range from about 50°F (10°C) to 27°F (10°C).
Continental regions experience very cold winters and warm to cool summers. Strong winds, snowstorms, and very cold temperatures, sometimes below -22°F (-30°C) are typical in winter.
Generally, temperatures will average between 32°F (0°C) and 50°F (10°C).
These regions are mostly in the far north, from North Dakota eastwards to New York and Maine. But there are some small continental areas scattered throughout eastern regions, as far south as Arizona and New Mexico.
This is the climate you’ll experience if you go to the north pole, which is north of the Arctic Circle. It’s freezing cold!
Even in summer, the temperatures don’t go above 50°F (10°C). That’s the coldest it might get in dry-climate and some temperate areas.
In the U.S. you’ll experience a polar climate if you live in the extreme north of Alaska.
Choosing Pansies Seeds
When you choose your pansy seeds, be guided by information on the packaging. There are dozens of cultivars that differ in terms of plant size, heat tolerance, and flower color.
So what do you choose to plant?
The common garden pansy, Viola x wittrockiana, is descended from the viola. For generations, selective breeding has produced larger flowers, bolder colors, and made them more heat tolerant and cold hardy.
There are more than 250 cultivars, some of which have the same form and markings but vary in color. Colors range from purple white and yellow to pink and blue.
The true viola is a lot smaller than pansies, as are Johnny jump-ups, Viola cornuta, and Viola tricolor. But Johnny jump-ups are considerably more heat tolerant than pansies and they look very similar.
How to Plant Pansies Seeds
Pansies grow very easily from seed, but they do take a long time to mature. If you live in a cold climate, it’s best to start seeds indoors about 10-12 weeks before the last expected frost date.
You can plant the seeds in pots or seed trays. Simply fill with good quality potting soil or a seed-starting mix, which you can buy from a garden center, and press the pansy seeds into the soil.
Make sure they are properly covered, because they need to be in darkness to germinate. Once the seeds have germinated and are established seedlings, plant them in your garden.
If you have planted your pansy seeds in pots or plastic seed trays, you will need to remove them from the container before transplanting. A great eco-friendly solution is to plant your seeds in biodegradable containers that you plant in the ground.
Whether in biodegradable containers or not, plant the seedlings 6-8 inches apart. Also, make sure that the soil contains lots of organic matter, but avoid fertilizers with high ammoniacal nitrogen content.
Check the pH. It should be between 5.4 and 5.8. Also, ensure that the soil drains well.
How to Water Pansies
Once you have planted your pansy seeds, water frequently to keep the soil moist. You also want to eliminate any air pockets that may have formed around the roots.
Once they are growing, they need about an inch of water every week. If rain provides sufficient irrigation, stop watering.
It’s very easy to give pansies too much water. And the problem is that they can develop edema, which is abnormal water retention in plants.
Edema causes plants to discolor and leaves to die. The growth of the plants may be stunted and they will die back.
If you water by hand, do so in the morning so that the foliage has the rest of the day to dry in the sun. To avoid fungal diseases, direct the water onto the soil rather than spraying the foliage of the plants.
How to Grow Pansies
Growing pansies isn’t difficult.
You need good soil, consistent moisture, and sunshine. They like partial or full sun but aren’t humidity or heat tolerant.
This is why they do best in the spring and fall. If they are exposed to too much heat, they tend to get leggy. You will also find there are fewer flowers.
Pansies tend to form clumps rather than spread. They work well in borders but don’t generally form a solid ground over.
A good way to keep pansies flowering is to dead-head them regularly. When you spot a dead flower head, simply pinch it off together with small green seed capsules, if these are forming.
How long do pansies take to grow?
If you plant seeds, it will take 1-3 weeks for them to germinate, depending on the temperature of the soil. If you start seeds indoors, the seedlings will be ready to plant outdoors within about 10 weeks.
They are fairly slow growers. But if you plant cold-hardy winter pansies at the end of winter and early spring, pansies will flower for 5-7 months.
Fall planted pansies will begin blooming in spring and may continue well into the following fall.
From our informative planting guide, you will see that the time to plant pansies depends primarily on your climate conditions and the USDA plant hardiness zone where you live.
If you want to learn more, keep an eye out for seed companies that have regular email newsletters, like Pennington, Baker Creek Heirloom Seed Company, and Hudson Valley Seed Company. All you do is sign up for their newsletter, provide your email address, and you’ll receive lots of regular news about pansy and other seeds.