How to Grow Collinsia Plants in your Garden

Gardener's HQ Guide to Growing Innocence, Chinese Houses, and Blue Eyed Mary

Collinsia is a half hardy or hardy annual that reaches 30 to 60 cm in height.

It blooms in the middle of summer, with flowers of pink, blue or purple.

The flowers are often lip shaped, hence one of their common names – Bluelips; other names for Collinsia include Innocence, Blue-eyed Mary, and Chinese Houses.

It is a great plant to grow in borders even in containers.

Collinsia heterophylla
Collinsia heterophylla - Chinese houses by MiguelVieira; Creative commons.

Collinsia tinctoria
Collinsia tinctoria - Tincture Plant by Marlin Harms.

Collinsia Growing and Care Guide

Common Names: Chinese Houses, Blue Eyed Mary, Innocence, Tincture Plant.
Life Cycle: Hardy annual or half hardy annual.
Height: 4 to 24 inches (10 to 60 cm).
Native: North America.

Growing Region: Zones 3 to 10.
Flowers: Mid-spring to Summer.
Flower Details: Pink, violet, white. Towering inflorescences. Lobed. Snapdragon-like.
Foliage: Coarse. Lanceolate. Sometimes toothed.

Sow Outside: 1/4 inch (6mm). Continuous sowing from early spring. Can also be planted in autumn in mild climates. Spacing 3 to 12 inches (8 to 30 cm).
Sow Inside: Germination time: two to three weeks. Temperature 70°F (21°C). Six or seven weeks in advance. Transplant outdoors following the last frost.

Requirements: Full sunlight or light shade. Soil pH 5 to 8. Good drainage. Rich soil. Regular watering. Stake taller species. Deadhead.
Family: Plantaginaceae.
Miscellaneous: Used as a traditional medicinal plants by native Americans.

How to Grow Innocence, Chinese Houses and other Collinsia

Seeds of should be planted outside in their final location either before the last frost of spring or in the autumn.

Innocence should be grown in a sunny garden or a partially shaded one in hot areas; plant them about 20 cm apart.

Collinsia likes to grow in a soil of pH 5 to 8, that is moist but well drained, and fertile.

The germination of Collinsia normally takes about two to three weeks.

Caring for Innocence

In windy areas Collinsia should be staked. The plant should be dead-headed to encourage flowering and prevent the Innocence taking over the garden.

Common Questions

How many members does the Collinsia genus have?

The Collinsia genus is made up of about 20 species.

Do members of Collinsia make a good garden or landscaping plant?

Collinsia, known for its attractive, often bi-colored flowers, makes a beautiful addition to wildflower gardens and informal landscapes.

Which Collinsia species are most frequently grown by gardeners?

One popular species is Collinsia heterophylla (Chinese houses), grown for its charming tiered flowers.

Are members of the Collinsia plant genus fragrant?

While Collinsia species are not notably fragrant, they are highly valued for their beautiful and distinctive blooms.

What is the perfect location to grow Collinsia?

Collinsia thrives best in part shade and in well-drained soil, making it a good fit for woodland or semi-shaded gardens.

Is Collinsia invasive in the USA?

Currently, Collinsia is not classified as invasive in the USA.

How do I remove Collinsia plants from my garden?

Remove Collinsia by carefully uprooting the plants and ensuring all root fragments are removed to prevent regrowth.


The Collinsia genus, part of the Plantaginaceae family, is native to North America. Also known as blue-eyed Mary or Chinese houses, these annual plants are known for their opposite leaves and small, tube-like flowers in various colors that bloom in spring or early summer.

To grow Collinsia, plant them in a sunny to partially shaded location with well-drained soil. They can be grown from seeds sown in spring. Regular watering is necessary. They are often used in wildflower gardens, meadows, or as cut flowers for their delicate, colorful blooms.

I hope that you enjoyed this guide on how to grow Collinsia plants. You may also enjoy the following Gardener's HQ growing guides: How to grow Rhodochiton and Veronica plants.