Harsh Paintbrush

This Harsh Paintbrush species should be watered deeply and regularly during the summer months, but reduce the amount of water once the cooler temperatures and rainier season begins. During the summer, the soil should be kept wet to a depth of 8 to 10 inches. The soil should be allowed to dry slightly between waterings. In the winter, the plant should be watered shallowly and infrequently, allowing the upper few inches of the soil to dry out between waterings. This species should not stay consistently wet during the winter.

Harsh Paintbrush typically grows in full sunlight and requires at least 6 hours of direct sunlight per day. It thrives in soil that is alkaline to neutral in pH and requires regular water, especially during the hot summer months. The plant will require deeper watering every 7-14 days, depending on the heat of the summer. In the spring and fall months, the watering frequency should be decreased to every 2-3 weeks.

Harsh paintbrush (Castilleja hispida var. hispida) is a perennial plant that should be pruned in late spring or early summer to encourage better branching and fuller growth. Pruning should be done selectively, removing only weak, dead, diseased, or damaged stems. Evenly trimming all stems can make for an unattractive plant shape. Pruning should take off no more than a third of the stems total height, although generally less than that is recommended. Avoid pruning the flowers, as most of the plant's flowering will take place on the second year of growth after being trimmed.