Common dog-violet

Common dog-violet: how do you recognise it?

Habit

Low rosettes 5–10 cm tall and up to 30 cm wide, without runners; the flower stems grow from the leaf axils, not from the centre.

Leaves

Heart-shaped, 2–4 cm, on long stalks, with a finely scalloped edge. Dark purplish green in the purple form.

Flower

Blue-violet, 1.5–2.5 cm, with a thick, pale to whitish spur notched at the tip. Unscented. Flowers from March to May.

Fruit

A three-valved capsule that splits and shoots out the seeds. Ants then carry them further.

Roots

A short, branched rootstock with fine roots.

Flowering: March–May · Plants: March–April and September–October

Why grow it?

• An early bloomer: blue-violet flowers from March to May in partial and full shade.
• Food plant for the caterpillars of several fritillary butterflies, and early nectar for bees and bumblebees.
• A loose, natural ground cover under shrubs, at the foot of a hedge or among ferns.
• Native and very easy: no feeding, no pruning, and it fills small bare patches by itself.
• The purple-leaved form adds colour to a shady corner all year round.

Common dog-violet: where does it grow best?

• Partial to full shade, under deciduous trees, shrubs or on the north side of a hedge. In full sun only if the soil does not dry out.
• Sand, loam or clay, acid to chalky, preferably with some humus from fallen leaves.
• Normally moist soil; it dislikes waterlogging and long drought in the sun.
• Plant 20–25 cm apart for a closed carpet after a few years.

Light

Partial shade and shade

Soil type

Sand, loam or clay

Acidity

Not fussy

Moisture

Normal

Size

0.1 m tall, 0.3 m wide

Hardiness

Hardy (to -30 °C)

Goes well with

• Wood anemone: White flowers in the same weeks and the same shade under deciduous trees.
• Primrose: Pale yellow flowers as a cheerful contrast with the violet.
• Sweet woodruff: Small white stars and fresh green leaves as a neighbouring ground cover.
• Ferns: Their fronds unfurl as the violet flowers and fill the space in summer.
• Greater stitchwort: White starry flowers at the foot of the same hedge.

Common dog-violet: when and how to plant it?

Plant in March–April and September–October.

1. Plant in March–April or in September–October.
2. Loosen the soil and mix in some leaf mould, especially under trees where the soil is poor and dry.
3. Set the plants at the same depth as in the pot; the centre of the rosette stays just above the soil.
4. Leave 20–25 cm between plants, in groups among other woodland plants.
5. Firm in and water well straight away. Keep the soil moist for the first weeks.

Care

Water

Water in the first spring and in dry spells. After that it looks after itself in shade.

Feeding

Not needed. Fallen leaves and a thin layer of leaf mould in autumn are enough.

Mulching

A layer of leaf mould keeps the soil moist, but do not cover the rosettes themselves.

Seedlings

Keep them where they are welcome and pull out the rest while they are small.

Caterpillars

Nibbled leaves in spring may be the work of fritillary caterpillars: let them be.

Tip: Let it self-seed freely in a shady border or under a hedge: a carpet forms by itself. The purple-leaved form, often sold as Viola labradorica, adds extra colour.

Common dog-violet: when to prune it?

When: It is not pruned. A little tidying in late winter is enough.

How:

• In February–March, remove brown, dead leaves by hand before the new leaves and flowers appear.
• Leave the spent flowers if you want it to self-seed.
• Pull out unwanted seedlings rather than cutting.

Pruning calendar and basic rules

Propagation

Seed

Pick the capsules as soon as they turn upright and light brown, and let them split open in a paper bag. Sow at once in a pot of seed compost left outdoors; the seed germinates after the winter cold.

Division

After flowering or in September: lift an older clump and split it into pieces, each with a rosette and roots.

Moving seedlings

Lift self-sown plants with a small root ball in spring or autumn and replant them elsewhere.

Common dog-violet: how does it get through the winter?

Hardy to −30 °C.

• Fully hardy, to about −30 °C: no protection is needed in Belgium.
• Some of the leaves remain in winter. Leave fallen tree leaves around the plants, but not thickly over the rosettes.
• In a pot: stand it in shade against a wall; it tolerates frost, but the pot must not become waterlogged.

Diseases and pests

• Slugs: Eat holes in the young leaves and flowers. Pick them off in the evening; in a wildlife garden, hedgehogs, toads and thrushes help.
• Red spider mite: Dull, finely speckled leaves, sometimes with fine webbing, in hot, dry summers. A cooler spot and watering help.
• Leaf spot and rust: Small brown spots or orange pustules on the leaves, mainly in damp weather. Remove affected leaves and do not plant too close together.
• Too many seedlings: It self-seeds freely, even in gravel and between paving. Pull them out while small or move them.

Through the year

• February: Remove brown leaves.
• March: Flowering starts. Plant.
• April: Full flower. Bees and bumblebees on the flowers.
• May: Last flowers. Look out for fritillary caterpillars.
• June: Pick ripe capsules and sow.
• July: Water in dry spells.
• September: Divide and plant. Move seedlings.
• October: Plant. Add a thin layer of leaf mould.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Butterflies

Nectar for butterflies.

Did you know?

• The caterpillars of several fritillary butterflies live on wild violets. Without violets these butterflies cannot breed.
• The ripe capsule shoots out its seeds. Each seed carries a small fatty appendage, so ants take them to their nest and spread them further.
• Unlike sweet violet, it has no scent. That is why it is called dog-violet in English: a violet of lesser worth, without perfume.