How to Grow Heartseases Canada

Quick Facts

Factor	Value
Drainage	Moist but well-drained; grows in any moderately fertile soil except waterlogged (RHS). NC State agrees: moist, well-drained preferred.
Lifecycle	Tufted annual, biennial or short-lived evergreen perennial with small tri-coloured flowers (purple, yellow and white, with "whiskery" markings) from spring to autumn. NC State: rapid growth rate, self-seeds and spreads via seed capsules holding up to 50 seeds each, though not considered particularly aggressive.
Edible parts	flowers
Documented problems	6 diseases, 8 pests

At a Glance

Diseases

Viola virus diseases (unspecified/unidentified)

low

RHS names "plant viruses" without further detail -- recorded at unspecified level.

Pansy leaf spot

low

Named directly by RHS.

Powdery mildew

low

Named directly by RHS ("powdery mildews").

Viola rust

low

RHS names "rust diseases" without a specific species.

Southern blight

moderate

Sclerotium rolfsii

Named directly by NC State ("southern blight of herbaceous ornamentals").

Black root rot

moderate

Named directly by NC State; RHS's UK guide does not mention it.

Pests

Glasshouse red spider mite (two-spotted spider mite)

low

Tetranychus urticae

Named directly by RHS ("glasshouse red spider mite").

Pansyworm (variegated fritillary)

moderate

Euptoieta claudia

Named directly by NC State: a caterpillar that feeds specifically on violets.

Aphids

low

Aphididae (various spp.)

Named directly by RHS.

Violet gall midge

moderate

Dasineura affinis

Named directly by RHS.

Thrips

low

Thysanoptera

Named directly by NC State ("thrips").

Caterpillars

low

Lepidoptera larvae

Named directly by NC State ("caterpillars") generically, alongside the specifically-named pansyworm below.

Snails

moderate

Gastropoda (snails, various spp.)

Named by both RHS and NC State.

Slugs

moderate

Gastropoda (slugs, various spp.)

Named by both RHS and NC State.

Growth Stages

Stage	BBCH	Notes
Sowing	0	RHS: propagate by seed sown in late winter or early spring. NC State: rapid growth rate, low maintenance; also propagated by division or stem cutting.
Establishment	3	Full sun or partial shade, moist but well-drained soil (RHS; NC State). NC State: water regularly but do not overwater; spacing under 12in given the plant's compact size.
Flowering	6	Flowers from spring to autumn (RHS); NC State gives a shorter spring-to-summer bloom window. Each seed capsule can hold up to 50 seeds, letting the plant self-seed and spread, though NC State notes it is not particularly aggressive.
Harvest and maintenance	8	RHS: cut back after flowering. NC State: flowers are edible with a slight minty flavour, best used sparingly as a garnish.

Harvest & Storage

When to pick: Flowers from spring to autumn (RHS); NC State notes the flowers are edible with a slight minty flavour.

Storage

Use fresh, sparingly, as a garnish (NC State).

What the research guides add

Heartsease is the wild ancestor of the garden pansy, and NC State describes it as short-lived but a reliable self-seeder.

• An annual, biennial or short-lived perennial wildflower, 3 to 10 inches tall and 3 to 12 inches wide, and the parent plant of modern pansy hybrids. (NC State Extension)
• It grows best in full sun and moderately fertile, moist, well-drained soil, and should be watered regularly but not overwatered. (NC State Extension)
• It blooms from spring to summer, is usually short-lived but freely reseeds, and each capsule can hold up to 50 seeds, although it is not particularly aggressive. (NC State Extension)
• The flowers are edible in small amounts but have little flavour, and are sometimes used as garnishes. (NC State Extension)

Heartsease in Canada: climate data

Frost dates and frost-free days are the median values for the stations in Environment and Climate Change Canada climate normals with the highest data-quality rating (1981–2010 normals).

Sources for this section

• NC State Extension: Viola tricolor (Plant Toolbox)

Section researched and checked on 25 October 2026 by the SoilCommander Editorial Team. How we check facts: editorial policy.

Sources

The full list of 2 sources behind this guide (North Carolina State University Extension (Plant Toolbox), Royal Horticultural Society) is in the references of our UK guide to heartsease; they describe the plant itself, which is the same wherever it grows.