Isotoma axillaris (Rock Isotome)
Botanical name: Isotoma axillaris
Common names: Rock Isotome, Showy Isotome, Blue Stars, Star Flowers
Family: Campanulaceae
Origin: Australia
USDA Zone: 10-11
Plant form: Small
Mature height: 2-5 ft
Sun exposure: Full sun or bright light indoor
Cold tolerance: Frost sensitive. Protect from freezing.
Watering: Moderate
Flower color: Pink; white and off-white; blue, lavender, purple
Suitable for: Outdoors in the suitable USDA zone; small gardens, containers, and indoor growingIsotoma axillaris is a small shrub that typically grows to a spreading clump 2-5 ft tall and 3-6 ft wide. It prefers a sunny location and moderate to regular watering. It can be grown in USDA zones 10-11.
The slender stems are lined with dark green, narrow, pinnatisect leaves. The foliage provides an interesting backdrop for the open star-shaped flowers, which come in shades of pink, blue, lavender, purple, white and off-white. The flowers attract pollinators such as bees and butterflies.
If you are growing Isotoma axillaris in a pot, they should be planted in a well-drained potting mix and kept in a sunny location. They will need regular watering and fertilizing. In areas with cold winters, bring the pot indoors before the temperature drops below 40 F (4 C). You can then move it back outside in spring after the frost danger has passed.
Isotoma axillaris is a great choice for adding texture and color to a garden border or rock wall. Best of all, it is easy to care for and will keep blooming from summer to fall.
