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Sweet John

Dianthus barbatus (dy-AN-thus bar-BAY-tus)

Family: Caryophyllaceae Non-native Herbaceous (1-3 ft)

Dianthus barbatus (Sweet William) is a biennial or short-lived perennial that is often grown as an annual. It thrives in loamy, slightly alkaline soil in sun or partial shade in hot summer climates. The flowers grow in rounded, dense clusters. Colors range from white through intense red and purple, often bicolor. There are many cultivars available, including double-flowered and dwarf forms. The epithet ' barbatus' refers to the barbed or beard-like growth arising from the petals. It is sometimes offered as a potted florist plant. It is susceptible to crown rot and rust, particularly in poorly-drained soils. and can be bothered by snails and slugs, particularly in shaded areas. This plant has poison characteristics: low toxicity only if eaten and minor skin irritation iasting only for a few minutes.

Source: NC State Extension Gardener Plant Toolbox ↗ NC State Extension Gardener Plant Toolbox, 63 attributes.

How it fits the guild

Guild layer 4 - Herbaceous (1-3 ft) Optimal soil pH Neutral (6.0-8.0)
See companions & conflicts ↓

Companions & Conflicts

Curated pairwise relationships between this plant and others in the library — who feeds whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.

No curated interactions recorded for this species yet.

Also noted by NC State

Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.

Fills a similar niche Clematis integrifolia Dianthus caryophyllus Dianthus chinensis x barbatus

Full plant profile

Growing Conditions
Plant type
Annual; Herbaceous Perennial; Poisonous
Life cycle
Annual; Biennial; Perennial
USDA zones
3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b
Light
Full sun (6 or more hours of direct sunlight a day) | Partial Shade (Direct sunlight only part of the day, 2-6 hours)
Soil texture
High Organic Matter; Loam (Silt); Sand
Soil pH
Neutral (6.0-8.0)
Soil drainage
Good Drainage | Moist
Available space
Less than 12 inches; 12 inches-3 feet
NC region
Coastal; Mountains; Piedmont
Mature size
Height: 1 ft. 0 in. - 2 ft. 0 in. | Width: 0 ft. 6 in. - 1 ft. 0 in.
Growth rate
Medium
Maintenance
Medium
Canopy layer
4 - Herbaceous (1-3 ft)
Form & Appearance
Habit / form
Dense; Erect; Rounded
Leaf color
Blue; Gray/Silver; Green
Leaf type
Simple
Leaf arrangement
Opposite
Leaf shape
Elliptical; Lanceolate; Oblong
Leaf margin
Entire
Leaf feel
Smooth
Leaf size
3-6 inches long
Hairs present
No
Leaf detail
Narrow lance-shaped leaves that are often grayish-green or blue-green to 4" long. Several oblong-lanceolate basal leaves, 4-10 pairs of cauline leaves. Short-stalked to stalkless
Flower color
Pink; Purple/Lavender; Red/Burgundy; Variegated; White
Flower value
Fragrant; Good Cut; Showy
Flower form
Cyme; Head; Umbel
Flower shape
Wheel
Flower size
1-3 inches
Flower detail
Flowers 5-parted with a frilled margin, often fragrant, shades of pink, red, often bicolor with white.
Bloom time
Spring
Fruit color
Black; Brown/Copper
Fruit type
Capsule
Fruit size
< 1 inch long, < 1 inch wide
Fruit detail
The capsule is 1-celled, opening by 4 valves, the fruit is dry and splits open when ripe with numerous, shield-shaped blackish-brown seeds.
Wildlife & Ecology
Native status
Non-native
Origin
European Mountains (Pyrenees, Carpathians, Balkans)
Wildlife value
Pollinated by Bees, Lepidoptera (Moths & Butterflies).
Attracts
Bees; Butterflies; Hummingbirds; Moths; Songbirds
Play value
Attractive Flowers; Attracts Pollinators; Colorful; Fragrance
Food & Medicine
Fruit type
Capsule
Landscape Use
Landscape location
Meadow; Patio; Recreational Play Area; Rock Wall; Slope/Bank; Small Space; Walkways
Landscape theme
Butterfly Garden; Cottage Garden; Cutting Garden; Pollinator Garden
Design feature
Border; Mass Planting; Small groups
Garden tags
#poisonous #pollinator plant #annual flowers #hummingbird friendly #cottage garden #red flowers #showy flowers #cutting garden #rounded #well-drained soil #bicolor #neutral pH #white flowers #purple flowers #pink flowers #colorful #fragrant flowers #loamy soils tolerant #moist soil #humidity tolerant #heat tolerant #HS302 #biennial #butterfly friendly #problem for dogs #problem for horses #problem for cats #full sun tolerant #bee friendly #upright form #rich soils #dense growth #partial shade tolerant #rabbit resistant #short lived
Problems & Resistance
Problems
Poisonous to Humans; Problem for Cats; Problem for Dogs; Problem for Horses
Resistant to
Deer; Heat; Humidity; Rabbits
Particularly resistant to
Deer and rabbit resistant
Propagation
Division; Seed
Poison severity
Low
Poison parts
Leaves
Poison symptoms
No reports of ingestion. Skin irritation reported from contact with clove pinks and vomiting.
Toxic principle
Triterpenoid saponins
Contact dermatitis
Yes
Toxicity summary
Low severity poison; parts: Leaves; contact dermatitis

Planted at Hunnicutt

Nobody’s planted this one yet.