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How to Grow California Bluebells

Phacelia campanularia

Hardy Cool Season Continuous Harvest

When to Start

Direct sow outdoors as soon as soil reaches 8°C — typically early to mid spring. Hardy enough to tolerate light frosts.

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Growth Stages

Sow seeds
Germination ~10d
Flowering ~50d

Approximate days from start

Care Essentials

  • Rarely needs feeding. A light application of balanced fertilizer at sowing is sufficient. Overfeeding produces foliage at the expense of flowers.
  • California Bluebells thrive on neglect. They prefer poor, sandy soil and minimal watering once established. Direct sow where they are to grow as they resent transplanting.

Companion Planting

Growing Conditions

Min. soil temperature: 8°C+

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Spacing & Planting

Plant spacing 15 cm
Row spacing 25 cm
Mature height 35 cm
Mature spread 25 cm

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Care Guide

Feeding
Rarely needs feeding. A light application of balanced fertilizer at sowing is sufficient. Overfeeding produces foliage at the expense of flowers.
Watch for
  • Aphids
  • Powdery mildew

Pests & Diseases

Pest Aphids

Identification: Clusters of small green or black insects on shoot tips and flower buds, causing distorted growth and sticky honeydew

Organic treatment:
  • Blast off with a strong jet of water
  • Spray with insecticidal soap or fatty acid solution
  • Encourage natural predators such as ladybirds and lacewings
Chemical treatment:
  • Spray with a contact insecticide containing pyrethrin
Disease Powdery Mildew

Symptoms: White powdery coating on leaves and stems, especially in warm dry weather with cool nights

Treatment: Remove badly affected leaves. Improve air circulation by thinning overcrowded plants

Prevention: Space plants well for good airflow, water at soil level, avoid overhead watering

Growing Conditions

Min. soil temperature8°C
Base growth temperature5°C
Photoperiod sensitivityday neutral

Frequently Asked Questions

How far apart should I plant California Bluebells?
Plant California Bluebells 15cm apart with 25cm between rows.
Is California Bluebells frost hardy?
California Bluebells is classified as Hardy.

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