How to Grow Phacelia Plants

Gardener's HQ Guide to Growing Heliotrope and California Bluebell

Phacelia plants are hardy annuals that reach from 30 to 60 cm in height.

Phacelia have a bush nature and carry heart shaped leaves; sometimes toothed.

They bloom in the summer when they carry blue or lavender bell shaped flowers.

Some of the common names for Phacelia include California Bluebell, Heliotrope, and Wild Heliotrope.

Phacelia sericea
Phacelia sericea – Silky Phacelia by Brewbooks; creative commons.

Phacelia incana
Phacelia incana (Hoary phacelia) by Matt Lavin; creative commons.

Phacelia Plant Growing and Care Guide

Common Names: Heliotrope, Wild Heliotrope, Scorpionweed, California Bluebell, Wild Canterbury Bells. Phacelia: Sand dune; Southern Sierra; Stinging; Weasel; Caterpillar; Alpine; Hiddenflower; Skyblue.
Family: Phacelia.
Life Cycle: Hardy annual. Hardy perennial.
Height: 8 to 30 inches (20 to 75 cm).
Native: Americas.
Growing Region: Zones 3 to 10.
Flowers: Summer.
Flower Details: Blue, violet, white. Bell-shaped.
Foliage: Herbaceous. Lanceolate. Oval. Cordate. Toothed.
Sow Outside: 1/4 inch (6 mm). Before the last frost. In warm areas can be sown in early autumn. Spacing 4 to 16 inches (10 to 40 cm). Germination time: two to four weeks in the dark. Temperature 55°F (13°C).
Sow Inside: No
Requirements: Full sunlight. Good drainage. Soil pH 6.5 to 7. Average soil. Can survive in dry soils. Pinch tips.

How to Grow California Bluebell, Heliotrope and other Phacelia Plants in the Garden

It is best to grow Heliotrope and California bluebells outdoors from seeds. Sow about 6 mm deep before the last frost of spring.

California bluebells, Heliotrope, and other Phacelia plants like to grow in sunny areas of the garden and likes a soil of pH 6.5 to 7. The soil type is not too important. It typically takes from two to four weeks for the seeds to germinate once the temperature reaches 12 to 16 degrees Celsius. Smaller species of Phacelia should be grown about 15 cm apart and larger varieties 25 to 30 cm apart.

Caring for California Bluebell - Phacelia

Once growing strongly young California Bluebells / Phacelia plants should be pinched back at the tips to facilitate branching. Phacelia species are tolerant of dry weather so only need to be watered in extremely dry conditions.

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