Pansies are exceptionally cold hardy and often beautify the landscape during the winter months. If your pansies are wilting, there are several possible reasons. Carefully examine the plants and the soil around them to help you identify the problem. Once you identify what is most likely causing the wilting, act fast so you can either revive your pansies or at least stop the problem from spreading to your other plants.
You need to start watering your pansies properly. Wilting is a sign of underwatering. Dig several inches into your soil. If it's dry, you may not be watering enough. In general, water pansies when the soil is dry to a depth of 2 inches. Then water them slowly with approximately 1/2 to 1 inch of water. Wilting is also a sign of overwatering. If the soil is super saturated, you may be watering too much. If you're not, improve the soil's drainage by incorporating some compost or coarse sand into the soil around your plants. You can also remove your pansies and transplant them in an area with better draining soil.
Fertilising Too Soon
If you fertilised your pansies at planting time, you may have caused them to wilt. Next time, wait about two weeks after planting before fertilising, to give them a chance to become settled in their new location. If you did in fact fertilise them too soon and they are already wilting, you may not be able to save the plants. Try giving them 1 or 2 inches of water to flush out some of fertilisers still remaining in the soil.
If your pansy's stems or crowns near the ground appear to be soft and brown, your plants may have crown rot. You may also be able to see tiny white or black spots. There's not much you can do about crown rot. Pull up the affected plants and throw them out so the rot does not spread in your garden. In the future, to prevent crown rot, always use sterilised garden tools and water plants in the morning so they will dry out during the day. Constantly wet plants are more likely to suffer from crown rot. You can also spray a preventive fungicide spray, such as Chlorothalonil, available in nurseries, following the application procedures written on the label.
Similar to crown rot, pythium crown and root rot symptoms often include the wilting of leaves. Yellowing leaves, dieback and root decay are also symptoms. Again, remove the affected plants from your garden and discard. Don't add them to your compost pile. If you want to replant pansies, replant them in a different area since the disease may still be in the soil.