Iris louisiana 'Her Highness' is a cultivar of Iris louisiana, commonly known as Louisiana Iris. It is a stunning herbaceous perennial that produces large, elegant flowers in shades of pink and lavender. Here's a detailed description and care guide for Iris louisiana 'Her Highness':

Description:
Iris louisiana 'Her Highness' features large, ruffled flowers with velvety petals in shades of pink and lavender. The blooms have a unique form with falls that curve downward and standards that stand upright, creating a striking contrast. The flowers typically have a yellow or white signal pattern at the base of each petal. They can reach a diameter of 10-15 cm (4-6 inches) and rise on tall, sturdy stems that can reach a height of 60-90 cm (24-36 inches). The foliage is long, slender, and bright green in color. It forms clumps of arching leaves that provide an attractive backdrop to the flowers.

Care Guide:

Light: Iris louisiana 'Her Highness' thrives in full sun to partial shade. It prefers at least 6 hours of direct sunlight per day to promote optimal flowering. However, it can tolerate some shade, especially in regions with hot summers, where it benefits from protection against intense afternoon sun.

Water: Louisiana Iris prefers consistently moist soil. Ensure the soil is evenly moist but not waterlogged. These plants can tolerate some periods of wet soil, but they should not sit in standing water for extended periods. Regular watering is important, especially during dry spells or in sandy soil. Mulching around the plants can help retain soil moisture.

Soil: Louisiana Iris prefers rich, slightly acidic soil that is moist and well-draining. They can tolerate a range of soil types, including clay, loam, or sandy soil. Amending the soil with organic matter, such as compost or well-rotted manure, before planting can improve its fertility and moisture retention.

Temperature: Iris louisiana 'Her Highness' is hardy in USDA hardiness zones 4-9. It is well-suited to moist, boggy areas and can tolerate both heat and humidity. In regions with extremely cold winters, providing a layer of mulch around the plants can help protect them from frost.

Fertilizer: Louisiana Iris plants benefit from regular fertilization. Apply a balanced slow-release fertilizer in early spring or incorporate a granular fertilizer into the soil before planting. Follow the package instructions for application rates. In subsequent years, you can apply a balanced liquid fertilizer during the growing season to promote healthy growth and abundant flowering.

Pruning: Minimal pruning is required for Louisiana Iris. After the flowering period, you can remove any spent flower stalks to maintain a neat appearance. In late fall or early spring, you can trim back the leaves to a few inches above the ground to allow for new growth.

Pests and Diseases: Louisiana Iris is generally resistant to pests and diseases. However, they may occasionally be affected by iris borer or slugs. Monitor your plants regularly and take appropriate measures to control any infestations. Good air circulation and proper spacing between plants can help prevent fungal diseases.

Iris louisiana 'Her Highness' is a regal and elegant perennial that adds beauty and color to garden beds, borders, or water gardens. By providing the right growing conditions and proper care, you can enjoy the exquisite flowers and attractive foliage of this cultivar in your landscape.