Hyssop
Hyssopus officinalis · Lamiaceae
A neat, aromatic, semi-evergreen subshrub with spikes of blue, pink or white flowers in midsummer. An old herb-garden edging plant that bees love.
- Size
- 20 in tall, 18 in wide
- Zones
- 4 to 9
- Light
- Full sun
- Flowers
- Early July to late August
- Pets
- No toxicity recorded
- Job in a bed
- Edging
A bed built around hyssop
The planner designed this bed around hyssop when this page was made: a 12 × 6 ft (3.7 × 1.8 m) cottage garden in zone 6, full sun. It chose the other plants from the 715 that suit those conditions and its dry soil, and says below why hyssop stands where it does.
The plants
- 1 Hyssop × 3, blue
- 2 Winter heath × 5, pink
- 3 Cheddar pinks 'Tiny Rubies' × 13, pink
- 4 New England aster 'Alma Pötschke' × 3, pink
- 5 Hyssop 'Blue Boa' × 5, purple
- 6 Silver sage × 1, silver leaves
- 7 Schubert's allium × 4, pink
- 8 Hyacinth × 12, yellow
Why this plant
- The only blue.
Why here
- At the back. At 20 in it is the step between Cheddar pinks 'Tiny Rubies' (4 in) in front and hyssop 'Blue Boa' (3 ft) behind: each is seen over the one before.
- A step in the back row. Next to New England aster 'Alma Pötschke' (3½ ft) and hyssop 'Blue Boa' (3 ft): no two neighbours there are the same height, so the back steps up and down like a skyline.
- 3 plants in one group. Massed, one kind reads as a single shape. Scattered, it would look spotty.
Why now
- In flower for 9 weeks. From early July to late August.
- Part of the bed's peak. With New England aster 'Alma Pötschke' and hyssop 'Blue Boa' in late August: 3 kinds at once. No week has more.
Planned as a cottage garden: 30 of the 30 plants (100%), bulbs aside, stand alone or in groups of no more than five, small enough for the kinds to mingle. Neither end outweighs the other: the visual weight is split 51 to 49, left to right. Cheddar pinks 'Tiny Rubies' is planted in three places along the bed, which gives it rhythm.
The planner's own design check: 11 Excellent, 6 Good. It flags one thing to watch: Nothing on this plan is highly poisonous or an aggressive spreader.
Open this bed in the planner Change its size, the sun or the style, move plants about, or swap one for another.
Where hyssop goes in a border
At 20 in it belongs in the middle of a bed. In the planner's ten height classes it is medium short (18 to 24 in).
Its job: edging. A low, neat plant used in short runs of three or five along the front to finish the edge (or, in a formal bed, in one even row).
It clips like lavender into a low, informal hedge and tolerates more cold. Cut it back hard in spring to keep it dense.
- A low hedge for a herb garden
- Edging a sunny path
- Pollinator gardens
What to plant with hyssop
Plants recorded as good partners for it, and what each pairing does:
- English lavender 'Hidcote': in flower together for four weeks, from early July; a low mound at the foot of its spires; happy in the same dry soil.
- Culinary sage: a low mound at the foot of its spires; happy in the same dry soil.
- Common thyme: flowers first, late May to late June, so the spot is never empty; a low mound at the foot of its spires; low enough (10 in) to stand in front of it.
Questions about hyssop
Does hyssop need sun or shade?
Hyssop grows in full sun (6 or more hours of direct sun a day).
It wants dry, sharply drained soil, on the lean side, with no feeding, and little watering once settled. Once settled in, it stands drought.
What zones does hyssop grow in?
USDA zones 4 to 9. It is hardy to zone 4, which means it survives winter nights down to about −20 °F (−29 °C).
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
When does hyssop flower in my zone?
In zone 5 it flowers early July to late August. As a summer flower it moves about half a week for every zone: earlier where it is warmer.
| Zone 4 | Mid July to early September |
|---|---|
| Zone 5 | Early July to late August |
| Zone 6 | Early July to late August |
| Zone 7 | Late June to late August |
| Zone 8 | Late June to late August |
| Zone 9 | Late June to mid August |
Worked out from Hopkins' bioclimatic law: spring arrives about four days later for each degree of latitude north, and one zone is roughly two degrees. A warm spring or a cold one moves any garden two weeks either way.
How far apart should hyssop be planted?
18 in (45 cm) apart, from the middle of one plant to the middle of the next. That is about its full width, so each plant keeps its own outline.
It grows 20 in (50 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many hyssop plants do I need?
At 18 in apart, set out in staggered rows:
- 5 to fill 10 square feet (about 1 m²)
- 7 for a single row 10 ft (3 m) long
- 17 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as runs of three or five along the front (or one even row, in a formal bed).
In the bed above, the planner used three in one group.
Is hyssop poisonous to dogs and cats?
No toxicity is recorded for dogs, cats, horses or people, according to NC State Extension.
"Not toxic" is not "edible": a pet that eats a lot of any plant can be sick.
Is there a native plant like hyssop?
Hyssop comes from Southern and eastern Europe, Northern Africa, West Asia. These North American natives come closest to doing its job:
- Threadleaf coreopsis 'Moonbeam': the same job in a bed, the same size and the same flowering time; belongs at the front, not in the middle, yellow, not blue.
- Yarrow: a drift, not an edging, 4 in taller.
- Tennessee coneflower: a drift, not an edging, 4 in taller.
Matched the way the planner's Swap button matches plants: the same job in a bed, then size, then flowering time.
Do deer eat hyssop?
Mostly not. NC State lists it as resistant to deer. No plant is proof against a hungry deer in a hard winter, but this one is low on the menu.
What flowers after hyssop?
Hyssop is over by late August. These start as it finishes and carry the same spot on, so it never goes flat:
- Garden chrysanthemum: from mid September to late October, 24 in tall.
- Bottle gentian: from late August to early October, 20 in tall.
- Garlic chives: from late August to mid September, 20 in tall.
What does hyssop look like in winter?
Hyssop holds some of its leaves into winter, more in a mild year or a sheltered spot, and they look tired by March. Cut the old ones off as new growth starts.
Is hyssop good for bees and butterflies?
Hyssop is visited by bees, butterflies and hummingbirds.
In these guides
- Plants for slopes and banks
- Deer-resistant perennials for full sun
- Drought-tolerant perennials for full sun
- Pet-safe plants for a sunny border
- Plants for hummingbirds
- Plants for butterflies
- Plants for bees
- Plants with spires: vertical accents
- Plants with blue flowers
- Plants for a white garden
Zone guides: Zone 4 · Zone 5 · Zone 6 · Zone 7 · Zone 8 · Zone 9
Every fact on record
- Type
- Perennial
- Size
- 20 in (50 cm) tall, 18 in (45 cm) wide
- Plant
- 18 in (45 cm) apart
- Height class
- Medium short (18 to 24 in)
- Place in the bed
- Middle
- Flowers
- Early July to late August; upright spires; blue, pink, white
- Leaves
- Fine texture, semi-evergreen; dark green
- Shape
- Upright, clumping
- Hardy in
- USDA zones 4 to 9
- Light
- Full sun
- Soil
- Lean, dry and sharply drained
- Water
- Low
- Feeding
- None needed
- Family
- Lamiaceae
- Comes from
- Southern and eastern Europe, Northern Africa, West Asia
- Attracts
- Bees, butterflies, hummingbirds
- Stands up to
- Deer, drought, poor soil, erosion
Checked against NC State Extension and VASCAN (plants of Canada). Flowering times are for zone 5: later in colder zones, earlier in warmer ones. Toxicity and spread information is a general gardening guide, not veterinary or medical advice, and invasive status varies by region. If a person or pet eats a plant, contact poison control or a vet. Check your local invasive species list before planting anything with a spread warning.