Pansy vs Viola: What the Difference Is and Which One to Grow

The difference you can see

Both belong to the same genus and are close enough that garden centers shelve them together, but they behave differently enough that the distinction is worth making before you plant. The quickest visual test is flower size and count. A pansy carries large flowers, commonly two to four inches (5 to 10 cm) across, and relatively few of them at any one time. A viola carries small flowers, roughly half an inch to one and a half inches (12 to 40 mm) across, and covers itself in them, so at a distance a viola reads as a solid sheet of color and a pansy reads as individual faces.

The petal arrangement differs too, once you look. A pansy flower has four petals pointing broadly upward and one pointing down, and the classic dark blotch at the center forms the face that gives them their appeal. A viola typically has two petals up and three down, and the markings run as fine dark whiskers radiating from the throat rather than as a solid blotch.

Habit follows from flower size. Pansies make larger, looser plants that stretch more readily and open up in the middle as the season goes on. Violas make tighter, more compact mounds that hold their shape for far longer and need cutting back less often. Neither is difficult, but the pansy is the one that will need your attention.

Where each one earns its place

Grow pansies where the flowers will be looked at closely and at short range: a container by a door, a window box at eye level, the front eighteen inches (45 cm) of a border you walk past. The large faced blooms are the whole point, and at that distance they are worth the extra deadheading and the shorter season.

Grow violas where you need color to hold over a long period without much intervention, or where the weather is against you. In an exposed position, under a rain gutter, in a bed you visit once a week, or in a climate with a short mild season at either end of the year, a viola will simply keep going where a pansy needs constant tidying to look presentable. They also carry a light sweet scent that most large flowered pansies have lost, which is a real argument for putting them near a path or a doorway.

In practice the most reliable planting is both together, with violas as the bulk of the display and pansies dotted through for the large faces. When the pansies go over in early summer, the violas carry the container for a further few weeks rather than leaving a gap.

Growing them differently

The care is broadly the same, with three practical differences. First, spacing: violas make a tighter plant and can be set four to six inches (10 to 15 cm) apart, while pansies want six to eight inches (15 to 20 cm) because their looser habit needs the airflow. Second, cutting back: a pansy will normally need cutting back by half at least once in a long season, and often twice, while a viola may go the whole way through without it. Third, feeding: pansies respond more strongly to overfeeding by producing long soft growth, so if you are feeding a mixed container, feed to the pansy's tolerance rather than the viola's.

Deadheading is where the difference is smallest and most misunderstood. Violas are often described as self cleaning, and they are not. They set seed just as readily as pansies do, and a viola allowed to ripen a full crop of pods slows and yellows exactly the same way. What is true is that a viola has enough flowers in production that the slowdown is less obvious for longer. Take the whole flower stalk off at the crown on both of them, and simply accept that on a viola you are working through more flowers.

Both self seed readily if you let them, and viola seedlings in particular will appear in paving cracks and at the edges of beds for years afterwards. Whether that is a bonus or a nuisance depends on the garden, but it is worth knowing before you decide to leave a plant to set seed.

When you plant a mixed container, note which side is pansy and which is viola. When the pansies collapse in the first hot week and the violas do not, the record of what was planted where is what tells you the proportions to use next year.

The strains you will meet, without naming names

Beyond the basic split there are a few groupings worth recognizing, all describable by what they do rather than by variety name. Large flowered pansies, the biggest blooms of all, are the most spectacular and the most easily wrecked by rain and wind; keep them under an eave or in a sheltered spot. Medium flowered pansies give up some size for markedly better weather resistance and are the better choice for open ground.

Winter flowering pansy strains have been selected to keep producing buds in short days and low light, which ordinary strains will not do, and they are the ones worth planting if you actually want flowers through the darkest weeks rather than just plants that survive them. If a pansy planted in autumn goes quiet all winter and only starts in spring, that is very likely an ordinary strain rather than anything you did wrong.

Among the violas, the compact small flowered bedding types are the workhorses. There are also trailing and spreading forms that run twelve to eighteen inches (30 to 45 cm) and are meant for the edge of a container or the top of a wall rather than for bedding out, and perennial violas that will persist for several years in a cool spot instead of being cleared at the end of the season. Reading the habit description on the label tells you which of these you are buying far more reliably than the name does.