The ideal temperature range for pansies is 40F at night to 60F during the day. They produce their best flower show in the spring, then fade during the hot, summer weather, when they are usually removed and annuals planted in their place. During the warmer growing season, you may need to irrigate to maintain an adequate moisture level and to water-in fertilizer when it is applied. Never water pansies in the late afternoon or evening since this encourages disease development. Avoid high levels of nitrogen because it can cause plants to produce soft foliage and to rot easily.
Many gardeners use an organic fertilizer which gives a slow release over many months.
An average rate is about 1 pound per 50 square feet of pansy bed. Liquid fertilizer can also be used. Always check the application directions on the fertilizer label, and, if there is one, on the label from the package in which your pansy seed or plants came. Follow these directions carefully when applying fertilizer.