How to grow Hyssop

Hyssopus officinalis

Hyssop (Hyssopus officinalis) — a hardy, semi-evergreen herb of the mint family with a woody base, narrow aromatic leaves and spikes of purple-blue flowers from June to September that bees and butterflies love. The leaves have a strong minty, sage-like flavour, so use them sparingly. Its essential oil can cause convulsions, so hyssop is not for people with epilepsy, and hyssop tea is best avoided in pregnancy.

Checked against sources: October 3, 2026

Quick facts

Type	Herb
Family	Lamiaceae
Light	Full sun
Soil pH	7–8
Frost	tolerates light frost
Soil for sowing	from 10 °C
Germination	14 days
Seedlings ready	42 days
Sowing to harvest	90 days
Where it grows	Open ground, At home

When to plant

Sow for seedlings about 8 weeks before planting out.

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

The first harvest comes about 90 days after the shoots appear.

Frost dates · When to plant

Care

Open ground

Stage	Watering	Temperature	Feeding
Germination	every 2 days	—	—
Seedlings	every 3 days	—	—
Growth	every 7 days	—	—
Harvest	every 10 days	—	—

At home

Stage	Watering	Temperature	Feeding
Germination	every 2 days	—	—
Seedlings	every 3 days	—	—
Growth	every 4 days	—	organic, 30 days into the stage
Harvest	every 4 days	—	—

Growing notes

Light

Full sun; in partial shade it grows leggy. In hot summers a little afternoon shade helps.

Soil

Light, free-draining, preferably chalky soil, pH 7.0–8.0. It copes with poor, dry and sandy soil, but in soggy soil the roots rot.

Care

Sow indoors in March–April about 5 mm deep — seedlings come up in two to three weeks — or straight outside after the last frost, and plant out about 45 cm apart once frosts are over. Water new plants regularly until they root in; after that hyssop tolerates drought, though pots need watering in hot weather. Let the top 2–3 cm of soil dry out between waterings. It needs little feeding; pot plants welcome an occasional liquid seaweed feed. Pick leaves as needed before flowering, and cut flowering tops for drying as the flowers begin to open. Cut plants back in mid-spring and remove faded flowers to keep them bushy. Divide every 3–4 years and replace plants after about five years. It is fully hardy and needs no winter cover. For a pot, pick one at least 35 cm deep and wide.

Pests and diseases of Hyssop

Scale insects

Sources

Figures checked against these sources.