Though this plant only lives for two years, these fancy little flowers often reseed themselves if conditions are favorable. It does well near other plants, especially grasses, because of its hemi-parasitic nature. In plain language, this means that the the scarlet painted cup burrows its roots into the root system of nearby plants in order to siphon nutrients and water. Though not essential for the survival of a scarlet painted cup, this rooting action supplies it with nutrients to thrive and produce flowers. It’s worth noting that this practice rarely harms the host plant. Good hosts for scarlet painted cup plants include blue eyed grass, bluebonnet, and beardtongue. Choose a host native to your area, if possible. These plants are best used for naturalizing open fields, native plant gardens, wildflower gardens, meadows, and prairies because of their hemi-parasitic nature and the need to grow near preferred host plants. They are not a good fit for manicured, composed gardens. Establishing scarlet painted cup plants is as simple as direct-sowing seeds in the ground and watching them grow, but make sure the area has well-draining soil that receives full sun. They are not usually affected by many common pests or diseases.
Light
Because the scarlet painted cup plant is naturally found in wide open areas, this wildflower needs full sun to thrive. These plants can have unpredictable foliage coloring, and shady conditions will further hinder bloom development.
Soil
The scarlet painted cup appreciates moist but well-draining soil. These plants are naturally found in prairies, rocky glades, moist and open woodlands, thickets and streambanks as well as in the sandy soil of semi-deserts and grasslands. Choose a planting location with excellent drainage to prevent overly-wet conditions.
Water
Keep scarlet painted cup plants well-watered for the first year, but be sure the soil isn’t soggy. Once they are established in their second year, they can be drought-tolerant but prefer medium moisture.
Temperature and Humidity
The scarlet painted cup plant prefers areas with cooler climates, even tolerating very cold winters. It cannot tolerate extreme heat and grows best in zones 4 to 8. Because it prefers moist, well-draining soil, it enjoys moderate humidity.
Fertilizer
The scarlet painted cup is one plant you don’t want to fertilize. In fact, over-fertilizing can harm the plant. Adding compost to soil in the spring is fine to do, but additional fertilizer is not recommended.
Scarlet Painted Cup Varieties
Castilleja ambigua ‘Johnny-nip’: This variety boasts bracts in yellow, white, pink, or purple and is commonly found in the coastal salt marshes or wet meadows of California.Castilleja angustifolia ‘Desert Indian Paintbrush’: This plant sports gray-green to purple-red foliage and bright red bracts covering yellow flowers. As suggested by its name, these flowers thrive in the rocky, sandy soil found in deserts or scrublands. Castilleja cinerea ‘Ashgray Indian Paintbrush’: This variety is native to San Bernardino County, California. The Ashgray Indian paintbrush gets its name from the coat of gray hairs it wears. These fuzzy flowers come in dusty red and pink-purple and grow in dry areas such as deserts, scrublands, or woodlands. Interestingly, these plants produce different colored flowers based on the direction they are facing. Northern-facing flowers tend to be more yellow while southern-facing flowers are redder.
Growing Scarlet Painted Cup Plants from Seed
The best way to grow scarlet painted cup plants is through seed. These plants do not transplant well. Sow your own scarlet painted cup seeds in early spring or late summer, when soil temperatures are around 55 to 65 degrees Fahrenheit. You can do this in the early spring or late summer.
