An understanding of how Pulmonaria grows outdoors is key to understanding lungwort plant care indoors.
Indoor Lungwort Plants
Pulmonaria naturally grow in cooler areas, likes to be in partial shade to full shade, and prefers rich, moist soil. It grows 1-2 feet (30.4-61 cm.) wide and only grows about 6-12 inches (15-30 cm.) tall. Keeping these things in mind gives us important clues on how to grow indoor lungwort plants. By the very nature of growing plants in containers, the soil tends to dry out much more quickly than in the ground. Keep a close eye on the soil for your indoor lungwort plants and make sure that the soil never dries out completely. That being said, although Pulmonaria likes moist soil, you must still use soil that is freely draining. Never allow your soil to completely dry out. As far as fertilizing goes, apply a little time-release fertilizer in the early Spring and that should be sufficient for the year.
Moderate Temperatures
Keeping in mind where and how they grow outdoors, indoor lungwort plants will not like hot and dry areas, and they also do not like very sunny areas. Pulmonaria indoors however, will benefit from some sun, since the intensity of sunshine indoors is much less than outdoors. Definitely avoid any windows that have hot, mid-day sun. Giving your indoor lungwort plants a little morning or late afternoon sun is beneficial. One important thing to remember for growing Pulmonaria indoors is that you should try to provide good air circulation if you can, and avoid stagnant air in order to discourage powdery mildew. Providing a little bit of direct sun for your Pulmonaria indoors will also help deter powdery mildew. If you see any powdery mildew, remove the affected leaves and spray the plant with horticultural oil. Lastly, after flowering occurs, you will need to spruce up your plant a little. Remove the spent flower stalks and any older leaves that look to be past their prime. Lightly pruning your plant back will help to rejuvenate it and encourage fresh, new growth.
