Phacelia plants are hardy annuals that reach from 30 to 60 cm (1 to 2 feet) 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 – Silky Phacelia by Brewbooks; creative commons.
Phacelia incana (Hoary phacelia) by Matt Lavin; creative commons.
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.
It is best to grow Heliotrope and California bluebells outdoors from seeds. Sow about 6 mm (1/4 inch) 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 (54 to 61°F).
Smaller species of Phacelia should be grown about 15 cm (6 inches) apart, and larger varieties spaced at 25 to 30 cm apart (10 to 12 inches).
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, California Fuchsia, California Pitcher Plant, and Mertensia plants.