Aaron's beard
Hypericum calycinum · Hypericaceae
A low, spreading groundcover with very large, golden flowers filled with a brush of long stamens. It grows in dry shade and poor soil, and runs underground.
- Size
- 14 in tall, 24 in wide
- Zones
- 5 to 9
- Light
- Full sun to part shade
- Flowers
- Late June to late August
- Pets
- Toxic (moderate)
- Job in a bed
- Carpet
A bed built around Aaron's beard
The planner designed this bed around Aaron's beard when this page was made: a 12 × 6 ft (3.7 × 1.8 m) English border in zone 6, part sun. It chose the other plants from the 708 that suit those conditions, and says below why Aaron's beard stands where it does.
The plants
- 1 Aaron's beard × 3, yellow
- 2 Blue moor grass × 8, purple
- 3 Leadwort × 15, blue
- 4 Purple milkweed × 3, purple
- 5 Swamp milkweed 'Ice Ballet' × 3, white
- 6 Inkberry 'Gem Box' × 1, dark green leaves
- 7 Meadow saffron × 7, pink
- 8 Daffodil × 5, orange
Why this plant
- The only yellow.
- Part of the bed's structure. Shrubs and grasses keep their shape when the perennials die down. So do blue moor grass and inkberry 'Gem Box'.
Why here
- Under the taller plants. It runs back between them as living mulch: there its job is to cover the soil, not to be looked at.
- 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 late June to late August.
- Part of the bed's peak. With purple milkweed and swamp milkweed 'Ice Ballet' in early July: 3 kinds at once. No week has more.
Planned as an English border: 8 of the 8 groups (100%) are drifts, longer along the bed than they are deep. The back corners are held by swamp milkweed 'Ice Ballet' and purple milkweed, the tallest plants on the plan. There is more leadwort than anything else, 15 plants in all.
The planner's own design check: 11 Excellent, 5 Good, 1 Satisfactory. It flags one thing to watch: Meadow saffron is highly poisonous to people, dogs, cats and horses. Aaron's beard spreads aggressively.
Open this bed in the planner Change its size, the sun or the style, move plants about, or swap one for another.
Where Aaron's beard goes in a border
At 14 in it belongs at the front of a bed. In the planner's ten height classes it is short (12 to 18 in).
Its job: carpet. A groundcover planted in threes and fives to cover the soil: along the front, and just behind it.
It will cover the most difficult dry bank, in sun or shade, and then keep going. Use it only where paving or mown grass stops it. Mow or shear it in early spring.
- Covering dry banks
- Groundcover under trees
- Contained areas only
What to plant with Aaron's beard
Plants recorded as good partners for it, and what each pairing does:
- Daylily: in flower together for seven weeks, from late June; tall enough (2½ ft) to stand behind it.
- Lilyturf: purple against yellow, opposite each other on the colour wheel, if you choose those colours, in flower together for three weeks; spires rising out of its mound.
- Hosta: its green leaves are a setting for the flowers, before and after; bold leaves against its medium ones; spires rising out of its mound.
Questions about Aaron's beard
Does Aaron's beard need sun or shade?
Aaron's beard grows in full sun (6 or more hours of direct sun a day), part sun (4 to 6 hours of sun, including some afternoon sun) and part shade (2 to 4 hours of sun, mostly in the morning).
It wants ordinary well-drained soil, of average fertility, and little watering once settled. Once settled in, it stands drought.
What zones does Aaron's beard grow in?
USDA zones 5 to 9. It is hardy to zone 5, which means it survives winter nights down to about −10 °F (−23 °C).
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
When does Aaron's beard flower in my zone?
In zone 5 it flowers late June to late August. As a summer flower it moves about half a week for every zone: earlier where it is warmer.
| Zone 5 | Late June to late August |
|---|---|
| Zone 6 | Late June to late August |
| Zone 7 | Late June to mid August |
| Zone 8 | Late June to mid August |
| Zone 9 | Mid June to early 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 Aaron's beard be planted?
18 in (45 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 24 in (60 cm), so a group knits into one patch.
It grows 14 in (35 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many Aaron's beard 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 threes and fives, along the front and just behind it.
In the bed above, the planner used three in one group.
Is Aaron's beard poisonous to dogs and cats?
Yes: moderate toxicity to people, dogs, cats and horses. All parts are poisonous if eaten, and can make the skin of animals blister in sunlight.
Rated from NC State Extension. Where references disagree, the more cautious rating is used.
Is there a pet-safe plant like Aaron's beard?
These come closest to doing what Aaron's beard does, and no toxicity is recorded for them:
- Lowbush blueberry: the same job in a bed and the same size; flowers early May to late May, white, not yellow.
- Strawberry 'Lipstick': the same job in a bed; 8 in shorter, flowers mid May to early September.
- Spotted dead nettle 'Beacon Silver': the same job in a bed; 8 in shorter, flowers early May to late July.
Matched the way the planner's Swap button matches plants: the same job in a bed, then size, then flowering time.
Do deer eat Aaron's beard?
They may. NC State does not list it as resistant to deer or rabbits. Where they visit, protect it, or plant it among ones they avoid.
Will Aaron's beard spread?
It spreads sideways, by runners or roots; the risk of it taking over is high. Spreads aggressively by underground runners and is hard to remove once established. It has escaped into the wild on the West Coast. Plant it only where it can be contained.
What flowers after Aaron's beard?
Aaron's beard 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.
- Japanese anemone: from mid August to early October, 3 ft tall.
- Sedum 'Autumn Joy': from mid August to mid October, 24 in tall.
What does Aaron's beard look like in winter?
Aaron's beard 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 Aaron's beard good for bees and butterflies?
Aaron's beard is visited by butterflies.
More Hypericum
- Golden St John's wort 'Sunburst' Hypericum frondosum 'Sunburst'
- Kalm's St John's wort Hypericum kalmianum
- St John's wort 'Hidcote' Hypericum 'Hidcote'
In these guides
- Plants for dry shade
- Garden plants toxic to cats
- Garden plants toxic to dogs
- Plants for butterflies
- Groundcover plants
- Shrubs under 4 feet for small gardens
Every fact on record
- Type
- Shrub (groundcover)
- Size
- 14 in (35 cm) tall, 24 in (60 cm) wide
- Plant
- 18 in (45 cm) apart
- Height class
- Short (12 to 18 in)
- Place in the bed
- Front
- Flowers
- Late June to late August; open bowls; yellow
- Leaves
- Medium texture, semi-evergreen; green
- Shape
- Mat-forming, spreading
- Hardy in
- USDA zones 5 to 9
- Light
- Full sun, part sun, part shade
- Soil
- Average, well-drained
- Water
- Low
- Feeding
- None needed
- Family
- Hypericaceae
- Comes from
- Southern Europe, Western Asia, Turkey
- Attracts
- Butterflies
- Stands up to
- Drought
Checked against NC State Extension. 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.