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Perennials
Trachystemon orientalis
giant borage
BoraginaceaeEurope, Asia
At a Glance
TypePerennial
HabitSpreading
FoliageDeciduous
Height18–24 inches (45–60 cm)
Width24–48 inches (60–120 cm)
Maturity3 years
Growing Zones
USDA Hardiness Zones
5 - 9Zone 5
Zone 6
Zone 7
Zone 8
Zone 9
These zones indicate the coldest temperatures this plant can typically survive.
Frost Tolerancehardy
Key Features
Attracts Pollinators
Deer Resistant
Drought Tolerant
Maintenancevery low
Overview
Trachystemon orientalis, commonly called giant borage or Abraham-Isaac-Jacob, is a robust, rhizomatous herbaceous perennial in the family Boraginaceae, native to moist, shaded woodland margins, stream banks, and the understory of deciduous forests in eastern Bulgaria, northern Turkey, and the western Caucasus. It belongs to a monotypic genus and is the largest-leaved hardy member of the borage family reliably grown in Pacific Northwest gardens. The flowers appear first — emerging in late winter to early spring (February–March) on branched, leafless, bristly-hairy stems 8–14 inches (20–35 cm) tall — well before the foliage. The flowers are small (0.5 inch / 1.2 cm across), violet-blue with a distinctive white-fringed corolla tube and five reflexed petals, borne in coiled, scorpioid cymes. Following flowering, enormous, broadly heart-shaped, rough-hairy leaves emerge — 10–16 inches (25–40 cm) long — and expand rapidly to form a dense, smothering, weed-suppressing groundcover canopy 18–24 inches (45–60 cm) tall by midsummer. The leaves persist as a handsome, bold-textured groundcover through the summer and autumn before dying back. An underused and exceptionally tough shade groundcover for the Pacific Northwest, where it tolerates deep, dry shade under large conifers — a notoriously challenging planting situation.
Native Range
Native to moist deciduous woodland understory, forest margins, and stream banks in eastern Bulgaria (Strandzha region), northern Turkey (Pontic region), and the western Caucasus, growing in humus-rich, moist to moderately dry soils under deciduous tree canopy. Not native to North America.Suggested Uses
Giant borage is one of the most effective groundcovers for the shaded Pacific Northwest garden, combining very early violet-blue flowers with spectacular, bold-textured, weed-suppressing foliage. Outstanding for large-scale planting under mature trees and conifers where dry shade and root competition defeat most other plants. Effective on shaded slopes and in awkward, difficult-to-maintain positions. The enormous, textured leaves create strong contrast with fine-leaved woodland plants. Combines effectively with Epimedium, Symphytum, and Lamium in a robust, low-maintenance shade groundcover tapestry. Allow 3–4 feet (90–120 cm) per plant.How to Identify
Appearance
Size & Dimensions
Height1'6" - 2'
Width/Spread2' - 4'
Reaches mature size in approximately 3 years
Colors
Flower Colors
purple
blue
Foliage Colors
green
Fall Foliage Colors
yellow
Bloom Information
Bloom Period
~4 weeksJ
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Spring
Detailed Descriptions
Flower Description
Violet-blue; small, 0.5 inch (1.2 cm), reflexed petals with white-fringed corolla tube; in coiled cymes on bare stemsFoliage Description
Broadly heart-shaped, enormously large (10–16 inches / 25–40 cm), rough-hairy, prominently veined, mid-greenGrowing Conditions
Sun Requirements
Partial Shade
Full Shade
Tolerates up to 4 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Soil Requirements
pH Range5.5 - 7.5(Neutral)
357912
Soil Types
loamclaypeatsand
Drainage
average
Water & Climate
Water Needs
Low
Frost Tolerance
hardy
Time to Maturity
2–3 years
Drought Tolerance
Drought tolerant when established
Care & Maintenance
Care Guide
Plant in partial to full shade in any reasonably fertile, moist to moderately dry soil. Giant borage is one of the toughest shade groundcovers available for Pacific Northwest gardens — it tolerates deep, dry shade under conifers, invasive tree roots, and other difficult conditions that defeat most shade perennials. Incorporate organic matter at planting and water during the first season to establish. Once established, largely self-sufficient. The spreading rhizomes form a dense colony — allow adequate space or contain by edging. Remove any dead leaves in early spring before flowering. Well-suited to large-scale difficult shade planting, underplanting large trees and conifers, and shaded slopes where little else will grow.Pruning
Cut or rake away the dead foliage in late autumn or early spring before the flowers emerge. No other pruning required. The rhizomes spread steadily; define boundaries by edging in spring. Division can be done in early spring to propagate or check spread.Pruning Schedule
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early spring