Silverleaf phacelia
Phacelia hastata · Hydrophyllaceae
The gardener's calendar
Ideal time to plant silverleaf phacelia: set it out when the soil is neither frozen nor waterlogged, and water generously as it establishes.
ID card
- Foliage
- Deciduous
- Flowering
- Spring to summer (April-July)
- Mature size
- 12-24 inches tall
- Growth
- Fast
- Hardiness
- Tender (temperate to warm climate)
- Origin
- Western United States
- Soil type
- Well-draining, dry to moderately moist
Care
Light
Phacelia hastata thrives in full sun, ideally with at least 6 to 8 hours of direct light daily. It tolerates partial shade but will flower less abundantly. Avoid overly shaded areas that would delay flowering.
Watering
Water regularly during growth and flowering, keeping the soil lightly moist without waterlogging. Once established, the plant will tolerate dry periods better. Reduce watering in late summer, as this plant is annual or short-lived.
Soil and Preparation
Prepare soil rich in organic matter, well-draining and low in lime. A light addition of compost at sowing aids rooting. Avoid compacted soils that slow growth and encourage damping-off of seedlings.
Fertilizer
Diluted balanced fertilizer applied once monthly during growth supports flowering. Avoid excess nitrogen, which favors foliage at the expense of flowers. Moderate feeding suffices for this undemanding plant.
Pruning and Maintenance
No obligatory pruning, but pinching young plants encourages denser branching. Remove spent flowers to extend flowering. Leave a few flowers to set seed if you want natural reseeding the following year.
Diseases and Pests
Phacelia is generally robust. Monitor excess moisture, which favors damping-off or mildew. Aphids may occasionally appear; a water spray or mild insecticide suffices. Few serious problems reported under normal conditions.
Did you know?
Phacelia hastata is renowned for its interesting allelopathic properties: it naturally produces compounds that inhibit germination of other plants, making it an excellent cover crop to regenerate and clean soils between plantings. Its attractive flowers, heavily visited by pollinators, also make it a great asset for supporting bees and butterflies in the garden.
Where to buy it
Plant in spring or early autumn, avoiding spells of intense heat. Pick a plant with healthy foliage and roots that are not exposed. Best time: March, April, May, September.
Add this plant to my garden →Plants from the same family
- PhaceliaPhacelia tanacetifolia
- Virginia waterleafHydrophyllum virginianum
- Distant phaceliaPhacelia distans
- Baby blue eyesNemophila menziesii
- Caterpillar phaceliaPhacelia cicutaria
- CamelliaCamellia japonica
Tips generated and checked by Viridia — adapt them to your local climate.