Sweetgrass vs Anise Hyssop - TreeTime.ca

Sweetgrass vs Anise Hyssop

Anthoxanthum nitens (Hierochloe odorata)

Agastache foeniculum

CUSTOM GROW

NOT AVAILABLE THIS SEASON - MIGHT RETURN

Sweetgrass
Anise Hyssop

Sweetgrass is a cool-season perennial grass best known for its sweet, vanilla-like fragrance. The scent comes from coumarin in the leaves, which is pleasant to humans but has a bitter taste that makes the plant less appealing to deer and other herbivores. As a cool-season grass, Sweetgrass grows most vigorously in spring and fall, slowing or even going dormant during the heat of summer.

It spreads quickly through creeping rhizomes and can be difficult to remove once established, so it is best planted in areas where its spread will not cause problems. Due to its deep, vigorous root system and preference for moist soils, Sweetgrass is especially useful for erosion control, soil stabilization, riparian plantings, and naturalization projects.

Note: Sweetgrass was formerly classified under the scientific name Hierochloe odorata and its subspecies. The subspecies found in Canada are currently considered two distinct species: Anthoxanthum hirtum, which is native across Canada, and Anthoxanthum nitens, which is native to Eastern Canada. Because these two species are alike and share many overlapping common names, they are often considered as only one species.

Anise Hyssop is a native perennial wildflower known for its fragrant spikes of small purple flowers. This plant is an excellent source of nectar and is highly attractive to a variety of bees and other pollinators. Deadheading spent flowers will encourage more blooms throughout the season.

Its aromatic leaves release an anise-like (licorice) scent when crushed. Both the leaves and seeds are edible and have been used in teas and as flavouring. Leaves can be harvested at any time, though the oil content is highest just past full bloom. Deer tend to avoid Anise Hyssop because of its strong-smelling leaves. This makes it a useful plant for positioning as a protective border around more vulnerable species.

Anise Hyssop spreads by seeds and rhizomes, but is less aggressive than other members of the mint family and is easy to remove if needed. Historically, it was planted in large numbers as a honey plant to support apiaries. Birds also feed on its seeds, adding to its ecological value.

As a perennial, it dies back to the crown each winter, it will regrow from the base in the spring. Avoid disturbing the crown during late winter to ensure healthy growth the following season.

Sweetgrass Quick Facts

Anise Hyssop Quick Facts

Zone: 1a
Zone: 3b
Height: 0.5 m (1.5 ft)
Height: 0.9 m (3 ft)
Spread: 0.5 m (1.5 ft)
Spread: 0.6 m (2.0 ft)
Light: partial shade, full sun
Light: partial shade, full sun
Moisture: normal, wet
Moisture: dry, normal
Growth rate: fast
Growth rate: fast
Life span: short
Life span: short
Growth form: arching to upright, colony-forming
Growth form: upright, clump-forming
Spreading: rhizomes - high, seeds - low
Spreading: seeds - high, rhizomes - medium
Maintenance: medium

Toxicity: toxic if large amounts ingested

Foliage: fragrant, bright green
Foliage: aromatic when crushed
Flowers: spikes of purple flowers
Bloom time: summer to fall
Hybrid: no
Hybrid: no
Catkins: no
Catkins: no


Native to: AB, BC, SK, MB, ON, QC, NS, NB, NL, YT, NT, NU, PE
Native to: AB, SK, MB, ON, NT
Other Names: bison grass, buffalo grass, holy grass, sweet grass, vanilla sweetgrass
Other Names: blue giant hyssop, giant hyssop, lavender hyssop