Thryallis (Galphimia gracilis) is a lovely and versatile plant often used in landscaping for its bright, cheerful blooms. Here’s a comprehensive guide to its care and uses:

Care
Watering: Thryallis prefers regular watering but is fairly drought-tolerant once established. Keep the soil consistently moist, but avoid waterlogging.
Soil: It thrives in well-draining soil. Sandy or loamy soils are ideal. Ensure the soil is slightly acidic to neutral (pH 6.0-7.0).
Fertilization: Feed with a balanced, slow-release fertilizer during the growing season (spring and summer). Avoid over-fertilizing as it can lead to excessive foliage at the expense of flowers.
Pruning: Light pruning after flowering can help maintain its shape and encourage new growth. Remove any dead or damaged branches to improve air circulation and appearance.
Size
Height: Typically grows to about 3-6 feet (0.9-1.8 meters) tall.
Width: It can spread 3-4 feet (0.9-1.2 meters) wide.
Flowers
Appearance: Thryallis produces small, bright yellow, trumpet-shaped flowers. They are borne in clusters and bloom continuously or sporadically throughout the growing season.
Bloom Time: Flowers primarily from late spring through fall, with the peak in summer.
Hardiness Zone
USDA Hardiness Zones: Thryallis is hardy in zones 9-11. It can tolerate some frost but may die back in colder climates.
Landscaping Use
Hedge or Screen: Its dense growth makes it an excellent choice for hedges or screens.
Accent Plant: Use it as a focal point in garden beds due to its vibrant blooms.
Container: It can also be grown in large containers or pots, especially in cooler climates where it can be moved indoors during the winter.
Ground Cover: In warmer regions, it can be used as a low-maintenance ground cover.
Additional Tips
Pests and Diseases: Generally resistant to pests and diseases, but keep an eye out for aphids or spider mites. Ensure good air circulation to prevent fungal issues.
Mulching: Applying mulch around the base can help retain soil moisture and regulate temperature.
Temperature Sensitivity: In regions where it’s not frost-tolerant, consider growing it as an annual or in a container so it can be protected from extreme temperatures.
With its vibrant color and adaptable nature, Thryallis is a great addition to many garden styles, providing year-round visual interest in warmer climates.