Sweet flag 'Ogon'
Acorus gramineus 'Ogon' · Acoraceae
Fans of narrow, glossy leaves striped gold and green, like a small, evergreen iris. It thrives in wet soil and shallow water and is not a true grass.
- Size
- 10 in tall, 12 in wide
- Zones
- 6 to 9
- Light
- Full sun to part shade
- Flowers
- Grown for its leaves
- Pets
- No toxicity recorded
- Job in a bed
- Edging
A bed built around sweet flag 'Ogon'
The planner designed this bed around sweet flag 'Ogon' when this page was made: a 12 × 6 ft (3.7 × 1.8 m) naturalistic planting in zone 6, part sun. It chose the other plants from the 708 that suit those conditions, and says below why sweet flag 'Ogon' stands where it does.
The plants
- 1 Sweet flag 'Ogon' × 7, chartreuse leaves
- 2 Green-and-gold × 31, yellow
- 3 Swamp milkweed 'Ice Ballet' × 3, white
- 4 Blue wood aster × 3, lavender
- 5 Globe arborvitae 'Danica' × 1, green leaves
- 6 Camassia × 5, blue
- 7 Surprise lily × 3, pink
Why this plant
- Part of the matrix. The low fabric of grasses and groundcovers that the taller plants come up through.
- Grown for leaf, not flower. So is globe arborvitae 'Danica'. Leaf lasts all season, where a flower lasts a few weeks.
- Part of the bed's structure. Shrubs and grasses keep their shape when the perennials die down. So does globe arborvitae 'Danica'.
Why here
- On the front edge. At 10 in it frames the bed without hiding it, and it is in leaf all season. It finishes 51% of the edge.
- 7 plants in 2 runs (4 and 3). Runs of different lengths make the edge a frame, not a ruled line.
Why now
- Here for its leaves, all year. They cover the 18 weeks between early March and late November when nothing on the plan is in flower.
- One of two evergreens. They are what the bed has to show from November to March.
Planned as a naturalistic planting: low grasses and groundcovers, the matrix, make up 65% of the planted ground. The scheme leans cool (lavender, blue and pink) and uses yellow for warmth, with white to calm things between them. Green-and-gold repeats along the bed to tie it together.
The planner's own design check: 10 Excellent, 7 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 sweet flag 'Ogon' goes in a border
At 10 in it belongs at the front of a bed. In the planner's ten height classes it is low (6 to 12 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).
Bright gold all year, in a place too wet for most gold-leaved plants. The fans make a tidy edging beside water. It scorches if it dries out.
- Gold edging for moist soil and pond sides
- Evergreen colour in part shade
- Containers
What to plant with sweet flag 'Ogon'
Plants recorded as good partners for it, and what each pairing does:
- Black mondo grass.
- Blue star creeper: adds the flowers, late May to early August; low enough (3 in) to stand in front of it; happy in the same moist soil.
- Hosta 'Halcyon': bold leaves against its fine ones; tall enough (18 in) to stand behind it; happy in the same moist soil.
Questions about sweet flag 'Ogon'
Does sweet flag 'Ogon' need sun or shade?
Sweet flag 'Ogon' 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 soil that stays evenly moist, of average fertility, and plenty of water. It copes with soil that stays wet.
What zones does sweet flag 'Ogon' grow in?
USDA zones 6 to 9. It is hardy to zone 6, which means it survives winter nights down to about 0 °F (−18 °C).
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
How far apart should sweet flag 'Ogon' be planted?
10 in (25 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 12 in (30 cm), so a group knits into one patch.
It grows 10 in (25 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many sweet flag 'Ogon' plants do I need?
At 10 in apart, set out in staggered rows:
- 17 to fill 10 square feet (about 1 m²)
- 13 for a single row 10 ft (3 m) long
- 55 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 seven in two groups.
Is sweet flag 'Ogon' 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 sweet flag 'Ogon'?
Sweet flag 'Ogon' comes from Japan, Korea and eastern Asia. These North American natives come closest to doing its job:
- Sedge 'Bunny Blue': the same job in a bed and the same size; medium leaves, not fine.
- Coral bells 'Firefly': the same job in a bed and the same size; flowers late May to late July, medium leaves, not fine.
Matched the way the planner's Swap button matches plants: the same job in a bed, then size, then flowering time.
Do deer eat sweet flag 'Ogon'?
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.
What does sweet flag 'Ogon' look like in winter?
Sweet flag 'Ogon' keeps its chartreuse and variegated leaves all winter, so it is one of the plants that hold a bed together from November to March, when the perennials have gone.
In these guides
Every fact on record
- Type
- Grass
- Size
- 10 in (25 cm) tall, 12 in (30 cm) wide
- Plant
- 10 in (25 cm) apart
- Height class
- Low (6 to 12 in)
- Place in the bed
- Front
- Flowers
- None: grown for its foliage
- Leaves
- Fine texture, evergreen; chartreuse, variegated
- Shape
- Arching, clumping
- Hardy in
- USDA zones 6 to 9
- Light
- Full sun, part sun, part shade
- Soil
- Average, evenly moist
- Water
- High
- Feeding
- None needed
- Family
- Acoraceae
- Comes from
- Japan, Korea and eastern Asia
- Stands up to
- Wet soil, erosion
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.