Phacelia

( fas - SEEL - ee - uh )

At-A-Glance Information

This genus of flowering annuals, commonly known as Scorpionweed or Heliotrope, needs little to moderate water and full sun to perform well. These flowers will attract beneficial insects to your garden, and are easy to grow. Flowers come in varying shades of blue, and bloom in springtime. Use Phacelia plants in mixed beds, borders, in container plantings, and as part of pollinator or native landscapes. Take care when planting these flowers in your garden, as all plant parts can cause an allergic rash to form on exposed skin.

Phacelia Species and Varietals

The genus Phacelia is a member of the plant family Boraginaceae and includes around 200 distinct species. The genus name is derived from the Greek word for 'cluster' or 'bundle', referring to the grouping of flowers. Phacelia grows best in zones 1-3 and 7-24. To find your zone, click here: Zone Map.

Phacelia anelsonii (Aven Nelson's Phacelia)
These plants are native to Utah, Nevada, and California. They are typically found growing in scrub or woodland habitats, and the species is named for botanist Aven Nelson. These annual plants reach up to 20 inches tall when in bloom, and produce lavender-purple to white flowers in a coiling cyme.

Phacelia argentea (Sand Dune Phacelia, Silvery Phacelia)
This species is native to the coastline of southwestern Oregon and northwestern California. It prefers to grow in sandy habitats in coastal areas, and produces a 18-inch tall plant with white to cream-colored flowers. The common name for this species was given due to the silvery sheen of the foliage on these plants.

Phacelia bolanderi (Bolander's Phacelia, Bolander's Scorpionweed, Blue-Flowered Grape Leaf, Caterpillar Flower)
These plants are native to Oregon and California coastlines, named for California botanist Henry Nicholas Bolander. These plants bear attractive, purple-lavender-blue flowers and strongly toothed leaves that resemble those of Grape (Vitis). They are commonly in flower during the warmer months of summertime.

Phacelia californica (California Phacelia, California Scorpionweed)
These wildflowers, native to California and Oregon, typically are found growing in chaparral, woodland, coastal, and grassland habitats. They can be either decumbent or erect, and reach up to 35 inches at maturity. Leaves are up to 8 inches long, and flowers are white to pale blue or lavender. These are a great food source for the endangered Mission Blue Butterfly.

Phacelia campanularia (California Desert Bluebells, California Bluebell, Desert Scorpionweed, Desert Canterbury Bells, Desertbells)
This native to the California desert areas reaches 6-18 inches tall and wide, with coarse grey-green leaves. Springtime flowers are deep blue and bell-shaped and have white dots at the base of each petal.

Phacelia cicutaria (Caterpillar Phacelia, Caterpillar Scorpionweed)
Native to California, Nevada, and Baja California, these plants grow mainly in chaparral habitats (frequently in areas that have recently burned). These upright annuals reach between 2 feet tall and have deeply lobed foliage. They are sometimes cultivated as ornamentals in native, wildlife, and pollinator gardens, and are great drought-tolerant flowers.

Phacelia crenulata (Notch-Leaf Scorpion-Weed, Notch-Leaved Phacelia, Cleftleaf Windheliotrope, Heliotrope Phacelia)
These plants are native to the southwestern United States, and western-central South America. These aromatic plants reach up to 32 inches tall when in bloom, and flowers are dark purple to violet in color. Inflorescences are coiled, like the tail of a scorpion, hence the common name Scorpion Weed.

Phacelia dalesiana (Howellanthus dalesianus) (Scott Mountain Phacelia, Howell's Phacelia)
These plants produce a few decumbent stems that are glandular and hairy in texture, and reach up to 6 inches long when mature. Inflorescences are small and curving, holding white flowers that have purple streaking towards the throat. The common name for this plant honors the John Thomas Howell.

Phacelia divaricata (Divaricate Phacelia)
Endemic to California, where it grows in the hills and mountain ranges around the San Francisco Bay Area, these annual herbaceous plants produce green foliage. Leaves are oval and either lobed or smooth-edged. Flowers are pale lavender and are bell or funnel-shaped.

Phacelia minor (Whitlavia, Wild Canterbury Bells)
These plants are native to southern California and Baja California, and is an annual herbaceous plant that reaches between 8 and 24 inches tall when in bloom. One-sided inflorescences hold many bell-shaped deep blue to lavender or purple flowers with protruding stamens. Anthers are white.

Phacelia purshii (Miami Mist, Scorpionweed, Purple Scorpionweed)
These plants are native to eastern and central North America, and reach between 12 and 18 inches tall when in bloom. Leaves are green and alternate, and flowers are light blue, violet, lavender, or almost white, with fringed lobes. Blooms are present on plants from April through June each year, and attract a bevy of pollinators.

Phacelia sericea (Silky Phacelia, Blue Alpine Phacelia, Purple Fringe)
These plants are native to subalpine and alpine elevations in western North America. The specific epithet sericea means 'silky', referring to the fine hairs on the leaves and stems of plants. Flowers are dark purple and have protruding stamens with yellow anthers. Individual plants reach about 2 feet tall when mature and in bloom.

Phacelia tanacetifolia (Lacy Phacelia, Tansy-Leaf Phacelia, Blue Tansy, Purple Tansy, Fiddleneck)
Native to northern Mexico as well as the deserts of southern California, this species reaches 1-4 feet tall and 1.5 feet wide. The plants have fernlike leaves and flowers are lavender-blue and bloom in coiled clusters at stem tips. They are very attractive to bees and other insects.

Caring for Phacelia

Phacelia can be purchased as a start from a reputable nursery, though plants are typically direct-sown in the garden after the last frost of the year passes by. Sow seeds 1/8 to 1/4 inch deep in compost-rich soil. Seedlings will emerge in 7-14 days. It is recommended to sow every 2-3 weeks in the spring to have successive blooms. These plants do best when massed together in a full sun to partial shade area of the garden. Ideally, they should be receiving between 6 and 8 hours of sun every day for the best blooms. For areas with warm temperatures, make sure these flowers get some afternoon shade when temperatures are at their peak (typically between 2 and 3 PM). Ensure that soil is well-draining, moderately fertile, and has a pH of between 6.0 and 7.5 (slightly acidic to neutral). Water new plantings regularly as they establish a strong root system. At maturity, Phacelia plants are considered to be somewhat drought tolerant, though they do appreciate regular waterings to avoid browning foliage. Phacelia flowers do not need to be fertilized or pruned, though to discourage re-seeding, make sure to cut back before they set seed. Because they are annuals, they are either pulled at the end of the year or left in place to enrich the soil for the following growing season.

Propagation

Phacelia is best grown from seed. To propagate your Phacelia flowers, follow the instructions below:

Propagating Phacelia by Seed

Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. If you don't have any potting medium on hand, you can make some. Just mix together equal parts (by volume) moss peat and horticultural-grade sand or grit sand. You will also, after a few weeks, need individual 3-inch pots for each seedling that grows.
Harvest your seeds. The seed pods are pretty easy to spot, they're left behind after flowers have faded. Once they have dried out and begun to split open, you can harvest the seeds inside. Cut them off of the plant, placing them in a paper bag. Harvest as many as you can, and place the paper bag in a dry, cool, dark area. They will begin to split open and release the seeds contained inside. Once they have been released, take them out of the bag and put them in a container so you can work with them.
Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 7-14 days from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.