It can be quite aggressive in garden beds due to its spreading rhizomes.

Does it need fertilizer?

No, it actually prefers poor soil and will become floppy if overfed.

Plant guide

Western mugwort.

Artemisia ludoviciana

Pronounced ar-te-MEE-zee-uh loo-doh-vik-ee-AY-nuh

Also known as Cudweed, Cudweed Sagewort, Gray Sagewort, Louisiana Sagewort, Louisiana Wormwood, Louisiana-sage, Mugwort Wormwood, Prairie Sage

Silver Wormwood — Photo by aarongunnar (CC BY) via iNaturalist

Western mugwort is a hardy perennial known for its beautiful silvery foliage. It spreads by rhizomes and brings a lovely texture to any garden space. You will find it is quite tough and handles dry conditions well.

Another photo of Western mugwort — Photo by Chelsea (CC BY) via iNaturalist

At a glance

Care level: Easy
Plant type: Perennial herb
Light: Full sun
Indoor light: Direct sun
Water: Every 7 to 14 days
Mature size: 3 feet tall
Growth rate: Fast
Hardiness: USDA 3 to 9
Bloom time: Mid to late summer

Care

Plant this in a spot with plenty of sun and well draining soil to keep it happy. Watch for powdery mildew if the air circulation is poor. You can easily control its spread by removing unwanted rhizomes in the spring.

Watering: Allow the soil to dry out completely between waterings to prevent root rot.
Feeding: A light application of compost in the spring is usually all it needs.
Pruning: Cut the stems back to the ground in late winter or early spring to encourage fresh growth.
Repotting: If growing in a container, move it to a larger pot once it becomes root bound.
Soil: Sandy or rocky well draining soil
Soil pH: 6.0 to 8.0
Temperature: -35 to 35°C
Humidity: 20 to 50%
Drought tolerance: High
Lifespan: Perennial, typically 5 to 10 years
Fragrance: Light
Deer and rabbits: High

Safety

People: The plant contains thujone and should not be consumed as it can cause digestive upset or nervous system issues.
Pets: This plant is generally considered toxic to pets if ingested in large quantities.
Children: Keep away from small children as the foliage is bitter and potentially toxic if ingested.
Contact allergens: The foliage can cause mild skin irritation in sensitive individuals.
Airborne allergens: The pollen is a common allergen for those sensitive to Asteraceae family plants.
Edibility: This plant is not considered edible and can be toxic if ingested in large quantities.

How to identify it

Silvery gray lance shaped leaves
Leaves covered in fine white hairs
Aromatic foliage when crushed
Small inconspicuous flower heads
Spreading rhizomatous growth habit

Height: 0.3 to 0.9m
Spread: 0.6 to 1.2m
Leaves: silver, gray, deciduous
Flowers: yellow, cream, 0.2 to 0.5cm

Problems to watch for

Powdery mildew · A white fungal growth on leaves often caused by poor air circulation or high humidity.
Root rot · Occurs when the soil stays too wet for too long, leading to root decay.

By symptom

Plant problems by symptom

Check your western mugwort from a photo

Pocket Botanist looks at a photo of your plant and tells you what's wrong and what to try first.

Growing it

Propagation: division, cuttings, seed
When to plant: spring, fall
Overwintering: Cut the stems back to the ground in late autumn or early spring. It is very hardy and requires no special winter protection.
In containers: It grows well in large containers, but ensure the pot has excellent drainage to prevent rot.

Plant this in a contained area or with very vigorous neighbors to prevent it from outcompeting smaller, delicate flowers.

Grows well with

Purple Coneflower · They share similar drought requirements and look beautiful together.
Little Bluestem · The silver foliage of the artemisia contrasts perfectly with the blue tones of the grass.
Blanket Flower · Both plants thrive in hot, dry conditions and provide a classic prairie aesthetic.

Similar species

Silver Mound · It has a much more compact, mounded habit compared to the spreading nature of A. ludoviciana.

Science

Family: Asteraceae
Genus: Artemisia
Order: Asterales
Class: Magnoliopsida
Native range: Widespread across North America from Canada to Mexico.
Conservation: This plant is widespread and secure across its native range.

It is a pioneer species that quickly colonizes disturbed sites and dry prairies.

Value to wildlife: larval host plant, nectar source
Pollinators: bees, butterflies, moths
Uses: xeriscaping, pollinator gardens, silver foliage contrast, dried arrangements

Through the year

JFMAMJJASOND

Flowering

Fruiting

Foliage

Ecological indicators

Salinity: 3/9
Soil reaction: 6/9
Light: 8/9
Temperature: 5/9
Moisture: 2/9
Nutrients: 2/9

Taxonomy resolved against GBIF.

Questions people ask

Is it invasive?: It can be quite aggressive in garden beds due to its spreading rhizomes.
Does it need fertilizer?: No, it actually prefers poor soil and will become floppy if overfed.

Where the name comes from

Artemisia is named after the Greek goddess Artemis, while ludoviciana refers to the Louisiana territory where it was first collected.

Good to know

It is also known as Western Mugwort.
Native American tribes used the leaves for ceremonial smudging.
The plant spreads aggressively via underground rhizomes.
It thrives in poor, rocky soils where other plants struggle.

Also in

Keep your western mugwort growing

This page is a general guide. Save your plant in Pocket Botanist and you get care reminders timed for this plant, plus a care history that shows what worked.

Get the app

This guide was generated with AI on October 19, 2026 and checked against GBIF taxonomy. It is general information, not horticultural or veterinary advice. Read about how we build these guides.