From gardens and hanging baskets to cocktails and gourmet dishes, pansies (Viola x wittrockiana) bring color and have been declared as some of the most favorite winter flowering plants for many reasons. People appreciate pansies due to the great variety of colorful flowers they produce. Nowadays, there are hundreds (around 500) of pansies varieties, with the new hybrids offering even more options regarding the color, color combination, plant, and flower size. Their mostly bicolor, velvety petals have dozens of fantastic color combinations, from white to yellow, purple, blue, and red, with dark centers and yellow eyes. Pansies with yellow flowers are generally planted in gardens and parks, alone or mixed with purple ones, because they stand out from a distance.
Pansies are perennial plants but are usually treated as annuals or biennials. Some popular pansy varieties are the Garden pansies (Viola x wittrockiana), the Johnny-jump-ups or heartsease (Viola tricolor), the Field pansies (Viola bicolor), and the Tufted pansies (Viola cornuta).
Which are the optimum conditions and places to grow pansies?
Except for the amazing flowers they produce, pansies are one of the gardeners' top choices to grow during winter, thanks to their ability to survive and bloom even in low temperatures. More specifically, the plants can withstand temperatures as low as 15 °F (-10 °C). However, the optimum temperature for plants' growth ranges between 40 and 70 °F (4-21 °C). Cool nights and relatively warm fall days can boost flowering. Usually, pansies can be planted (or sown) during fall and flower throughout winter and spring. However, due to the high sensitivity of these plants to high temperatures, pansies are grown as annuals in most areas since they usually cannot survive over the summer.
Pansies are outdoor plants and need plenty and direct sunlight to flower. They can perform great in gardens but also in pots-containers and hanging baskets. To ensure their good growth and health, we should avoid planting them in poorly drained soil since they are susceptible to waterlogging and wilt quickly. For this reason, in heavy soil, we can place them in garden beds and open enough drainage holes if we want to grow them into containers. Finally, pansies prefer slightly acidic soils with a pH of 5.4-6.
How to grow pansies from seeds
In most areas, you can successfully grow pansies from seeds with direct sowing to the ground or a container during late summer or early fall. Start by purchasing certified seeds to ensure a good germination rate, fast growth, and healthy plants. The ideal temperature for germination ranges between 45-65 °F (7-18 °C).
In areas where the conditions are not favorable for direct sowing outdoors, many gardeners choose to sow the seed in plant trays with high-quality seed starting (soil) mix or other growing media. Pansies seeds are very sensitive to light. For this reason, the seeds must be covered with sufficient soil, and the tray should be placed in a cool location protected from direct sunlight. Usually, good-quality seeds may germinate after 1 to 3 weeks, depending on the soil temperature. You can transplant them to their final location (or a larger pot) when the seedlings have developed 3-5 leaves.
Originally, pansies are biennials, meaning they complete their life cycle within 2 years (from seeding to senescence). During the first year, they produce foliage; during the second year, they bloom, set seeds, and die. However, most commercially available hybrids can flower already the first year after sowing.
Choose and transplant pansies
Pansies are usually planted in the fall. To have flowering plants directly, most people buy mature potted plants from garden centers or online nurseries. Choose vigorous plants with plenty of flower buds and not fully blooming ones.
Start by "cleaning" your pansies and removing all chlorotic and dried foliage as well as faded flowers. Remove the plants from their pots and gently loosen up the roots. All-purpose planting soils can be used for potted pansies. Depending on the pansy type, the plants can spread 9-12 in (23-30 cm) and become 6-9 in (15-23 cm) tall. You can place them 6-10 in (15-25 cm) apart, but pansies can grow well even at closer distances, fitting 4-8 plants in a pot/basket with a 6-8 in (15-20 cm) diameter. The planting hole should be a bit wider than the root ball and with the same depth. These plants are a great option to grow together with other season annuals (e.g., marigolds, dusty miller, dianthus, chrysanthemums, etc.).
Care tips for pansies – How to keep your pansies fully boomed for longer
Pansies are heavy feeders. Depending on the weather conditions and the location where the pansies grow, we may need to water them daily. Even during winter, pansies must be watered regularly (from rainfalls or manually) and keep the soil moist at all times. If you observe that your plants look cachectic or the flowering has been reduced even when the environmental conditions are optimum, try to water them a bit more often.
Fertilization is also essential for maintaining healthy and flowering plants. To cover their nutritional needs, all-purpose fertilizers rich in nitrogen can be used. Slow-release 15-9-12 fertilizers can be broadcasted and incorporated into the garden's top 2-3 in (5-7.5 cm) of soil. Soluble fertilizers are preferred and applied once every 2-4 weeks for plants growing in pots. Keep in mind that iron and boron deficiencies may occur in soils with a pH higher than 5.8. On the other hand, in soils with a more acidic pH (below 5.3), a magnesium deficiency is more common. Chlorosis of the foliage or limited growth and cachectic plants may be some common signs of nutrient deficiencies. If you already apply all-purpose fertilizers, you may also need to consider adding some fertilizers with micronutrients.
Another important practice that will help your pansies to bloom for longer is to remove the faded or dead flowers. Try to cut the flower stem as low as possible, taking care not to injure any leaves. To easily distinguish the older plants from the ones that will open in 1-2 days, remember that the young flowers tend to have their petals in a more closed and firm arrangement. Furthermore, the mature-older flowers usually have formed a small green "ball" at their center, after they have been pollinated, that encloses the seeds.
Pansies that grow in the garden are usually threatened by snails, slugs, several caterpillars, and aphids. More specifically, many different species of aphids can infest pansies, mostly during spring, when new tender vegetation appears. Chemical control has low success and is not preferred. To help your plants cope with this enemy, you can maintain a healthy garden with different plant species that will be able to attract and host important insect predators like ladybugs and parasitic wasps. So, you can let nature work on your behalf. Hand-picking may be needed to control the rest (snails, slugs, caterpillars). Finally, disease like root rots, mildews (downy and powdery mildew), or/and rust can infect both ground and potted grown pansies. To limit the spread of the problem, you can remove the infected plants, use healthy plants and soil and improve soil drainage. Due to its annual nature and the low cost of pansies, most gardeners prefer to replant. You can advise your local garden center and a licensed agronomist.
References
https://hgic.clemson.edu/factsheet/pansy-diseases-insect-pests/