The secret to happy pansies is to remember they like things cool. In temperate climates, you'll get the best results from young transplants set out in fall (for the earliest spring bloom) or in early spring, as soon as the ground can be worked. Where summers are generally cool- not over 90 degrees Farenheit- they bloom best in full sun and keep on going until fall. In hotter climates, look for heat-resistant cultivars and plant them in moderate shade. Where winters are mild, plant pansies in fall for bloom right through winter; then pull them up when the heat gets to them.
The easiest way to grow pansies from seed is to treat them like biennials. Sow them outdoors in midsummer, then plant them in their final home in fall, mulching well in cold winter areas. Is is possible to sow pansies indoors, although it is a bit of a challenge. Sow the seed indoors 14 to 16 weeks before the last frost date, barely covering it. Pleace the containers in your refrigerator for 2 weeks, and then expose the seed to room temperatures; it should sprout in about 10 days.
After germination, keep the temperature as low as you can; 50 to 65 degrees farenheit is ideal, but room temperature is acceptable. Plant out hardened-off seedlings as soon as the soil is workable.
Outdoors, water pansies as needed and deadhead them to help maintain blooming. Cut straggly plants back severely to stimulate new growth.
One of the few annuals that can be planted in fall for early-spring bloom, pansies play a unique role in the garden. Let them take the spring shift in an impatiens bed of front-door planter or fill in the ground level around tall daffodils. Tuck them around plants that thrive in part shade, such as ferns or purple-leaved heucheras (Heuchera hybrids), and they'll bloom well into summer.
Problems and Solutions:
Pansies are somewhat susceptible to leaf diseases: Choose disease-resistant strains, and rotate plantings if you notice repeated damage. Hand-pick slugs and snails if they become a problem.
Viola x wittrockiana (pansy): These large-flowered plants with overlapping petals are offered in an almost infinite range of colors, including a violet so deep it appears almost black. Most are bicolored with facelike markings, but some are all one color.