Persicaria odorata
Common Name: Asian mint 
Type: Herbaceous perennial
Family: Polygonaceae
Native Range: Southeastern Asia
Zone: 9 to 11
Height: 0.50 to 1.50 feet
Spread: 0.50 to 1.50 feet
Bloom Time: August to September
Bloom Description: White
Sun: Full sun to part shade
Water: Medium to wet
Maintenance: Medium
Suggested Use: Annual, Herb
Flower: Showy
Attracts: Butterflies
Tolerate: Rabbit, Deer, Wet Soil

Culture

Winter hardy to frost free areas of USDA Zones 9-11 where it is best grown in consistently moist to wet, moderately fertile soils in full sun to part shade. Plants prefer boggy soils including ones with some standing water. Best in part shade, but tolerates full sun as long as ample soil moisture and good air circulation are present. Plants grow best in warm and humid tropical to sub-tropical areas. Plants begin to struggle when temperatures dip below 45 degrees F. Pots can be brought indoors in fall for overwintering, but overwintering can sometimes be difficult because of the need to provide moist and humid growing conditions. Rather than try to overwinter indoors, it is an option to simply (1) purchase bunches of this herb in early spring from local Asian grocery stores where it is sold very inexpensively, (2) place stems in water until roots show, and finally (3) plant the rooted stems in a wet location or pot. First harvest of leaves occurs about 2 months after spring planting. Plant tips will root at the tips, rapidly forming colonies. Infrequently flowers in areas not having tropical weather conditions.

Noteworthy Characteristics

Persicaria odorata, commonly known as Vietnamese coriander or Vietnamese mint, is an herbaceous tender perennial of the knotweed family that typically grows to 6-18” tall. It is native to Southeast Asia. Leaves are used extensively in Vietnamese cooking to flavor soups, stews, and salads. Leaves have a coriander-like smell and a spicy, pungent, hot peppery flavor. Additional common names for this plant include rau ram, Laska leaf, Cambodian mint, daun kesom, phak phai and chi krasang tomhom. Reddish-green stems are clad with broad-ovate to triangular-ovate green leaves (to 2-4” long) which are spotted with chestnut-hued markings. Leaf undersides are tinged with burgundy-red. Campanulate white flowers (each to 1 1/4” long) bloom in late summer, but bloom infrequently occurs in cool climates.

Young leaves are used raw or cooked as a flavoring. Add young leaves to mixed salads or cook (sometimes as a late addition) with rice or vegetables, soups or stews (flavoring is destroyed by prolonged cooking).

Leaves are less frequently used as a diuretic, antipyretic, digestive tonic, or anti-aphrodisiac. Juice prepared from the crushed leaves was at one time taken as an antidote for treating poisonous snake bites.

Genus name comes from the Latin persica meaning peach-like and sagittata meaning barbed or arrow-shaped in reference to the shape of the leaves.

Specific epithet comes from Latin in reference to the aromatic and flavorful leaves.

Problems

No serious insect or disease problems.

Garden Uses

Where winter hardy, this plant may be grown in herb gardens for cultivation of its edible leaves. Mass as a ground cover in open woodland or cottage gardens. Moist borders. Containers. Where not winter hardy it may be overwintered indoors or grown as an annual.