How to grow Stock

Matthiola incana · hoary stock, gillyflower, Brompton stock

Stock (Matthiola incana) — a cool-season flower of the cabbage family, a biennial or short-lived perennial grown as an annual, with dense spikes of single or double flowers in white, cream, pink, red, purple and yellow and a strong clove-like scent. It flowers from late spring and keeps going into autumn where summers are cool, but stops in the heat. The flowers are edible.

Checked against sources: October 3, 2026

Quick facts

Type	Flower
Family	Brassicaceae
Light	Full sun
Frost	tolerates light frost
Soil for sowing	from 10 °C
Germination	10 days
Seedlings ready	35 days
Where it grows	Greenhouse, Open ground, At home

When to plant

Sow for seedlings about 6 weeks before planting out.

It tolerates light frost: plant out in open ground about three weeks before your last spring frost.

In an unheated greenhouse everything moves about three weeks earlier.

Frost dates · When to plant

Care

Greenhouse

Stage	Watering	Temperature	Feeding
Seedlings	every 2 days	—	—
Growth	every 7 days	10…27 °C	balanced (NPK), at the start of the stage
Flowering	every 7 days	10…27 °C	balanced (NPK), 14 days into the stage

Open ground

Stage	Watering	Temperature	Feeding
Seedlings	every 2 days	—	—
Growth	every 7 days	10…27 °C	balanced (NPK), at the start of the stage
Flowering	every 7 days	10…27 °C	balanced (NPK), 14 days into the stage

At home

Stage	Watering	Temperature	Feeding
Seedlings	every 2 days	—	—
Growth	every 2 days	10…27 °C	balanced (NPK), at the start of the stage
Flowering	every 2 days	10…27 °C	balanced (NPK), 14 days into the stage

Growing notes

Light

Full sun; tolerates some light shade.

Soil

Average to humus-rich, evenly moist, well-drained soil, neutral or slightly alkaline — it does poorly in acid soil.

Care

Sow 6 mm deep at 18–24 °C, 5–8 weeks before planting out, or sow outdoors at the last frost date. For more double flowers, keep the seedlings at 4–7 °C for 3–4 days at the seed-leaf stage and keep the lighter green ones — the darker ones flower single. Plants are frost-hardy and need 2–3 weeks of cool weather (10–13 °C) to set buds, so plant them out early, 10–15 cm apart; do not pinch them. Keep the soil evenly moist. Feed at planting and again 6–8 weeks later, without extra nitrogen — it makes stems weak — and watch for brown leaf tips, a sign of potassium shortage. Above about 27 °C flowering stops, so sow again every two weeks for a longer show and give tall varieties netting or a stake. Aphids, thrips, flea beetles and diamondback moth caterpillars attack it; white mould appears in mild, wet weather.

Pests and diseases of Stock

Sources

Figures checked against these sources.