Rue

Appalachian-Blue Ridge forests

Arizona Mountains forests

Atlantic coastal pine barrens

Blue Mountains forests

Canadian Aspen forests and parklands

Central Pacific Northwest coastal forests

Central Tallgrass prairie

Central-Southern Cascades Forests

Chilean Matorral

What it needs

Conditions

Light

Full sun

Water

Low water

Spacing

18"

Habit

Evergreen, woody-based sub-shrub with distinctive aromatic, fern-like, blue-green foliage and clusters of small mustard-yellow flowers in summer. Drought-loving and easy in hot, dry, full sun with sharp drainage; it rots on heavy, wet, or rich soil, and a hard spring cutback keeps it dense rather than woody and leggy. Honest, load-bearing caveats: it is PHOTOTOXIC — sap plus sunlight causes blistering skin burns, so handle only with gloves and covered skin, especially on bright days — and it is TOXIC if eaten and a historical abortifacient, so it should NOT be eaten today; grow it as an ornamental for the blue foliage. It is also a larval food plant for swallowtail butterflies.

Care tips

•

Give it full sun and SHARP drainage in lean, gritty, or poor soil — a raised bed, gravel garden, or sunny slope — and keep it dry; heavy, wet, or rich ground will rot it.

•

ALWAYS wear gloves and cover your skin when handling, pruning, or weeding around it, ideally on a dull day: rue is phototoxic and its sap plus sunlight causes blistering burns.

•

Cut it back hard in spring, into living growth, to keep it dense and blue rather than woody and leggy at the base.

Lifecycle

Planting

Plant in spring in full sun and lean, free-draining, even gritty or poor soil; a raised bed, gravel garden, or sunny slope suits it, and heavy, wet, or rich ground will rot it. Space about 18 inches apart, and wear gloves and cover your skin when handling — rue is phototoxic. RHS rates the species fully hardy (H5).

Transplanting

Move young, container-grown plants in spring, keeping the root ball intact and wearing gloves; established plants resent disturbance, so it is easier to start a fresh plant from a cutting than to lift and relocate an old one.

Early growth

Water lightly to establish through the first season, then taper off — once rooted it is strongly drought-tolerant and far happier kept dry than wet. Avoid feeding; lean conditions keep the foliage compact and well-coloured.

Maturity

Reaches roughly 2-3 feet tall and 1.5-2 feet wide and flowers in summer. Cut it back hard in spring, into living growth, to keep it dense and blue rather than woody and bare at the base — always wearing gloves and covering your skin, and ideally on a dull day, because the sap is phototoxic in sunlight.

Propagation

Easily raised from seed or from softwood or semi-ripe cuttings in summer, which root readily and renew this woody sub-shrub; named blue forms such as 'Jackman's Blue' are kept true from cuttings. Handle all propagation with gloves.

Similar plants

Browse lateral options with similar roles, light needs, size, or native-range overlap; these are not filtered for a better climate fit.

Achillea filipendulina

Fern-leaf yarrow

A tall, sun-loving, drought-tolerant perennial in the daisy family, grown for its broad, flat-topped corymbs of tiny golden-yellow flowers held on stiff stems above finely divided, aromatic gray-green ferny foliage. Native to the Caucasus, Iran, and Afghanistan and long naturalized in gardens worldwide, it forms a tidy upright clump (rather than running like common yarrow) and is one of the most reliable, low-care pollinator and cut-flower plants for hot, dry, full-sun borders.

Perennial

Full sun

Low water

Zones 3a-9b

Climate: moderate

Pollinator

Border

Structure

Filler

Verbena bonariensis

Tall verbena

An airy, see-through ornamental in the vervain family (Verbenaceae), native to South America and naturalized across the warm southeastern United States. NC State Extension describes an erect plant 2-5 feet tall on thin but strong red-marked green stems, topped from summer into fall by dense, flat-topped clusters of small tubular purple-lavender flowers held well above mostly basal, lance-shaped, serrated dark-green leaves. A perennial in USDA zones 7-11 (grown as an annual in colder climates), it is fast-growing, drought and deer tolerant, and a magnet for bees, butterflies, and hummingbirds — though it self-sows freely and some sources have labeled it invasive.

Perennial

Full sun / Part sun

Low water

Zones 7a-11b

Climate: moderate

Border

Pollinator

Filler

Structure

Artemisia absinthium

Wormwood

An aromatic, woody-based perennial grown above all for its finely divided, silky silver-grey foliage and pungent, bitter scent. Native across Europe, North Africa, and western and central Asia and widely naturalized beyond it, it carries small, dull-yellow flowers in nodding sprays in late summer above a soft mound of intricate, dissected leaves. It is the classic silver-foliage plant for contrast in a sunny, well-drained border. Note: this is the famous bitter herb of absinthe and vermouth, and it contains thujone, which is toxic in quantity, so it is grown for its foliage and never for eating.

Perennial

Full sun

Low water

Zones 4a-9b

Climate: moderate

Border

Filler

Structure

Kerria japonica

Japanese kerria

A cheerful, easy deciduous shrub of the rose family grown for two seasons of interest: bright golden-yellow flowers in mid-spring and slender, arching kelly-green stems that stay green through winter for a real cold-season feature. The single five-petaled species is pretty, but the double, pompom-flowered form "Pleniflora" is by far the most widely grown. Notably shade-tolerant — it actually flowers best in part shade, since full sun bleaches the blooms. The honest catch is its spread: it suckers and runs underground into a widening thicket, so site it where it has room to colonise or be ready to dig out the suckers. Despite the common name, POWO (Kew) places its native range in China, not Japan; it has simply been cultivated in Japan for a very long time. Grown purely for ornament — it is not a food plant.

Shrub

Part shade / Full sun

Moderate water

Zones 4a-9b

Climate: moderate

Border

Filler

Structure

Dryopteris marginalis

Marginal wood fern

A native evergreen fern with leathery dark blue-green fronds in upright vase-shaped clumps. Among the most drought-tolerant native ferns — useful for drier-shade settings where most other ferns fail. The "marginal" name refers to sori (spore clusters) carried at the leaflet margins. Evergreen through winter in zones 5+; reliably long-lived (20-30+ years).

Perennial

Part shade

Moderate water

Zones 3a-8b

Climate: broad

Filler

Border

Structure

Salvia rosmarinus

Rosemary

A Mediterranean-native evergreen aromatic woody subshrub long known as Rosmarinus officinalis (reclassified to Salvia rosmarinus in 2017 based on molecular phylogenetics). Highly drought-tolerant once established; pale-blue spring flowers; foliage harvested year-round in mild climates as the canonical Mediterranean culinary herb. Borderline-hardy in zones below 7 — overwintered indoors or treated as annual outside zones 8-10.

Herb

Full sun

Low water

Zones 8a-10b

Climate: narrow

Border

Edible

Structure

Sources & citations

Cite this page

For lesson plans, articles, or research that uses this page. To cite a single upstream fact instead, use its specific source listed below.

Plotwright. (2026, May 17). Rue (Ruta graveolens). Retrieved 2026, June 25, from https://plotwright.com/plants/ruta-graveolens

Sources for every fact

Every fact on this page traces to a source. 18 fields cited - 18 source-backed.

Plants of the World Online (POWO)

Botanical research database

Backs 17 fields

Identity

Summary

Plant type

Light

Moisture

Hardiness

Heat zone

Size

Spacing

Habit

Design roles

Seasonal interest

Growth stages

Lifecycle

Regional guidance

Success tips

Designer notes

Wikimedia Commons

Photo

Backs 1 field

Image

RHS Find a Plant

Botanical research database

GBIF

Botanical research database

Wikipedia (ecoregion articles)

Botanical research database