Pest Information

Great Valley Phacelia

Great Valley Phacelia

  • Latin Name: Phacelia Ciliata
  • Common Name: Great Valley Phacelia
  • Other Names: One of many species of related plants, but only a few of which are troublesome as weeds.

Pest Details

Great Valley Phacelia


Native to California, and present in much of the state, where it can be a problem in alfalfa fields as well as some vegetable crops.


An annual weed that rapidly grows to a large, bushy appearance, up to 20 inches tall and very widely branched and spreading. Reproduction is from seeds.


Mature plants are extensively branched, but the weak branches often bend and recline on or near the ground. Stems are angled and covered with both a layer of soft hairs as well as many stiff hairs. Leaves occur on a short stalk and are usually alternate along the stem. Leaves are deeply lobed to create from 7 to 11 leaflets, each with toothed margins. Flowers are showy and pinkish to bluish with light centers. They grow in clusters at the ends of the stems, often with several flowers crowded together. The stem of the developing flower head is curved “fiddle-like”, and opens as the flowers mature.

Characteristicts Important to Control:

Annuals reproducing from seeds, and physical removal of individual plants is effective.

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