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lacy phacelia

Phacelia tanacetifolia · Hydrophyllaceae

lacy phacelia (Phacelia tanacetifolia)
Photo: (c) Pavel Komkov, some rights reserved (CC BY) · CC BY · via iNaturalist

lacy phacelia (Phacelia tanacetifolia) is a annual herbaceous plant in the Hydrophyllaceae family. It is native to North America. USDA records it as hardy in zone 12 and warmer, down to about 52°F.

At a glance

Typeforb-herb USDA
Lifecycleannual USDA
Native statusnative USDA
Mature height4 ft USDA
Lightfull-sun USDA
Water needmedium USDA
Growth raterapid USDA
Soil pH6.4–8.6 USDA
BloomMarch–April USDA
Flower colorBlue USDA
Hardiness zones12 and warmer USDA
Guild layerherb-layer Derived
Nursery availabilityContracting Only USDA

USDA quoted from the USDA PLANTS database · Derived computed by a fixed rule from those columns. No value on this page is estimated.

Growing conditions

It needs full sun. USDA rates it as having moderate water needs. Its drought tolerance is rated medium. It tolerates saturated, poorly drained ground well (USDA rates its anaerobic tolerance high). It is recorded on soils from pH 6.4 to 8.6 — a broad range that spans acidic through mildly alkaline ground. Its cold limit is zone 12.

Size and growth

At maturity it reaches about 4 ft, making it roughly waist to chest height. It grows quickly.

Bloom period

USDA records a bloom period of March through April. Flowers are blue.

A flowering date, not a pollinator rating.

Foliage, flower and season

Summer foliage is green, medium in texture. Its flowers are conspicuous. Its active growth period is spring.

What the site needs to provide

USDA records it across sites receiving 8 to 18 inches of annual precipitation. The low end of that band is genuinely arid, so it has a wide tolerance for dry country. It needs at least 100 frost-free days to finish its season. It roots to at least 10 inches. Fertility requirement: low — no feeding needed on ordinary garden soil.

Propagating it

Seed is the only propagation method USDA lists. Division and cuttings are not listed as options. USDA records no cold-stratification requirement, so seed should germinate without a chilling period. Its seed spreads at a slow rate. It does not spread vegetatively, so it will stay where you put it.

Resilience and wildlife

Its fire tolerance is rated medium. Its growth form is recorded as single crown.

Role in a guild

Herb layer. In a layered planting this is the herbaceous middle — perennials and grasses that fill the space between ground cover and shrubs. The layer is derived by a fixed rule from growth habit and mature height.

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Tags

deciduousdrought-tolerantwet-tolerantclay-tolerantsandy-soilnativefull-sunfast-growing

Related plants

Others in Phacelia

Similar role and hardiness

Where this data comes from

Every value on this page comes from the USDA PLANTS database record for symbol PHTA, or is computed from those values by a fixed rule. Nothing here is estimated or model-generated. Where USDA publishes no value, this page omits the claim rather than filling the gap.

Read our full data sources and methodology.

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