Splitleaf Indian Paintbrush

Splitleaf Indian Paintbrush (Castilleja rhexiifolia) should be watered lightly and regularly throughout the growing season. Generally speaking, water once a week or every 5-10 days. In particularly hot or dry weather, water twice or 3 times a week. It is best to water in the morning, as any water droplets retained from sprinkling at night can increase the risk of fungal diseases. Ensure that the soil is moist but not soggy, and water from below so as not to disturb the stems and leaves. During the late fall and winter, keep the soil on the dry side, but still check it periodically to make sure it is not completely dry.

Splitleaf Indian Paintbrush (Castilleja rhexiifolia) grows best when it receives sunlight for a minimum of 4 hours per day, with 6 to 8 hours being even better. The best times to expose it to sunlight are between the hours of 10 a.m. and 4 p.m., when the light is brightest and most direct. In winter, when days are shorter, it needs a few extra hours of sunlight, with at least 4 hours a day.

Splitleaf Indian Paintbrush should be pruned only once a year in the spring. It is important not to prune too aggressively, as this will reduce the growth of the plant's flower production. Pruning should involve only the removal of dead or damaged stems, leaving only the healthy stems. Prune only lightly, removing no more than 1-third of the stems each year. Any pruning that occurs should be too low on the stems - they should not be cut back past the foliage.