Hyssop
Hyssopus officinalis
Bee-loved blue-flowered herb — a classic guard against the cabbage moth.
- Type
- Herb · Perennial
- Botanical family
- Mixed / other
- Foliage color
- Green
- Flower color
- Blue
- Sunlight
- Full sun
- Watering
- Low
- Soil
- Light, free-draining
- Feeding
- Leave it hungry; it does better on lean soil than on a fed one.
- USDA zones
- 4a–9b
- Frost tolerant
- Yes
- Flowering
- June
- Pruning
- Trim it after flowering, then prune hard in spring.
- Sow indoors
- 42 days before the last spring frost
- Sow direct
- at the last spring frost
- Plant out
- at the last spring frost
- First harvest
- 60 days after the last spring frost
- Harvest ends
- at the first fall frost
- Mar–Apr Bud Break
- Apr–May Spring Growth
- May–Jun Harvest
- Jun–Sep Flowering
- Sep–Nov Growing
- Nov–Dec Leaf Fall
- Jan–Mar Leaf Fall
- Plant spacing
- 11.8 in
- In-row spacing
- 11.8 in
- Between rows
- 15.7 in
- Square-foot density
- 1 per square
- Root system
- Fibrous
- Working depth
- 12–24 in
- Can reach
- 3 ft down where the soil allows
- Spread
- 16–24 in across, about 1–1.5× the width of the plant
- Shallowest pot
- 12 in of soil
A dense mass of roots through the topsoil with a few running deeper after water. Work the bed to a spade’s depth before planting and it will find everything it needs without much help.
The habit is Hyssop’s own; the figures are what that habit usually comes to at this size, not a measurement of this species. Roots follow the soil either way: a compacted pan, a high water table or heavy clay stops them well short of any of it, and deep open ground lets them go further.
- When
- Pick leafy tips from late spring, with the main harvest just as flowering begins in mid-summer, when the aromatic oils in both leaf and flower peak. Cut mid-morning on a dry day once dew has gone.
- What to look for
- Semi-evergreen stems dense with narrow dark leaves, strongly camphor-minty when crushed, and spikes of deep-blue (or pink/white) flowers just opening — flowers and leaves are both used.
- How to harvest
- Snip the top 10cm of flowering shoots with scissors or shears, cutting above leafy growth and never into the bare woody base. A general shear of the top third at flowering doubles as the annual tidy the shrub needs anyway.
- How often
- Light continual picking through summer plus one main flowering-time cut; a second, smaller flush often follows. Stop cutting by early autumn so growth hardens before winter; replace woody plants every 4–5 years.
- Storing the crop
- Fresh sprigs keep about a week in the fridge. Hyssop dries well — hang bunches in a dark, airy place and strip leaves and flowers into airtight jars, where the pungency keeps for around a year for teas and (sparing) culinary use.
- Generally trouble-free No notable pest or disease problems when grown in the right conditions — one of the easy ones.
Lavender, Sage, Cabbage, Grapevines
Good neighbors
Keep apart
Its blue flower spikes are so rich in nectar that beekeepers prize hyssop honey.
Green-leaved herbs, like this one.
The Cottage Garden Companion — the gardener's herbarium at cottagegardencompanion.com