Giant feather grass
Stipa gigantea · Poaceae
From a low, evergreen tuft of narrow leaves, stems shoot up to two metres and open into great, shimmering heads of golden oats that last all summer.
- Size
- 6½ ft tall, 3½ ft wide
- Zones
- 5 to 8
- Light
- Full sun
- Flowers
- Mid June to early August
- Pets
- No toxicity recorded
- Job in a bed
- Specimen
A bed built around giant feather grass
The planner designed this bed around giant feather grass when this page was made: a 12 × 6 ft (3.7 × 1.8 m) naturalistic planting 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 giant feather grass stands where it does.
The plants
- 1 Giant feather grass × 1, tan
- 2 Winter heath × 8, pink
- 3 Blanket flower 'Arizona Sun' × 5, red
- 4 Stiff goldenrod × 3, yellow
- 5 Little bluestem 'The Blues' × 4, tan
- 6 Eastern bee balm × 3, pink
- 7 Ornamental onion 'Purple Sensation' × 5, purple
- 8 Grecian windflower × 6, blue
Why this plant
- The only airy sprays. The others are bells, daisies, flat plates and others. Shape reads at a distance, where colours blur.
- Part of the bed's structure. Shrubs and grasses keep their shape when the perennials die down. So do winter heath and little bluestem 'The Blues'.
Why here
- Anchors a back corner. At 6½ ft it is the tallest plant here, and the tallest close the ends of the bed, where they stand in front of nothing.
- A step in the back row. Next to little bluestem 'The Blues' (3 ft): no two neighbours there are the same height, so the back steps up and down like a skyline.
- One plant, alone. A feature plant is seen as an object, and needs clear ground around it.
Why now
- In flower for 9 weeks. From mid June to early August.
- Part of the bed's peak. With blanket flower 'Arizona Sun' and eastern bee balm in mid June: 3 kinds at once. No week has more.
- Stands through winter. Left uncut, it holds its shape until March, when the perennials have gone.
Planned as a naturalistic planting: low grasses and groundcovers, the matrix, make up 44% of the planted ground. Cool colours (pink, purple and blue) with red and yellow as the warm notes, and tan to calm things between them. Giant feather grass and stiff goldenrod anchor the back corners of the bed: the tallest plants on the plan stand there.
The planner's own design check: 10 Excellent, 6 Good, 1 Needs revision. Its weakest point is height and scale: Heights average about 12 in at the front, 20 in in the middle and 3½ ft at the back. Along the back row the heights step up and down, between 2½ ft and 6½ ft, and no two neighbours are the same height. 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 giant feather grass goes in a border
At 6½ ft it belongs at the back of a bed. In the planner's ten height classes it is very tall (5 to 6½ ft). It is airy enough to see through, so it can also come forward and veil what is behind it.
Its job: specimen. A feature plant with a shape of its own. It stands alone with room around it, and repeats only at a distance.
The golden oats glow when lit from behind, and you see straight through them, so it can be planted near the front. It needs sun, space and good drainage.
- A tall, transparent specimen
- Catching the evening light
- Dry, sunny borders and gravel
What to plant with giant feather grass
Plants recorded as good partners for it, and what each pairing does:
- English lavender 'Hidcote': in flower together for six weeks, from late June; spires rising out of its mound; low enough (18 in) to stand in front of it.
- Russian sage: in flower together for five weeks, from mid July; spires rising out of its mound; low enough (4 ft) to stand in front of it.
- Sea holly: in flower together for six weeks, from early July; low enough (3 ft) to stand in front of it; happy in the same dry soil.
Questions about giant feather grass
Does giant feather grass need sun or shade?
Giant feather grass 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 giant feather grass grow in?
USDA zones 5 to 8. It is hardy to zone 5, which means it survives winter nights down to about −10 °F (−23 °C).
Above zone 8 it struggles: the zones measure winter cold, but a plant's top zone usually means the summers are too hot or the winters too mild for it to rest.
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
When does giant feather grass flower in my zone?
In zone 5 it flowers mid June to early August. As a summer flower it moves about half a week for every zone: earlier where it is warmer.
| Zone 5 | Mid June to early August |
|---|---|
| Zone 6 | Mid June to early August |
| Zone 7 | Early June to early August |
| Zone 8 | Early 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 giant feather grass be planted?
3 ft (90 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 3½ ft (100 cm), so a group knits into one patch.
It grows 6½ ft (200 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many giant feather grass plants do I need?
At 3 ft apart, set out in staggered rows:
- 1 to fill 10 square feet (about 1 m²)
- 4 for a single row 10 ft (3 m) long
- 4 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as one, with clear ground around it: a feature plant is seen as an object, and a group of them is a thicket.
In the bed above, the planner used one in one group.
Is giant feather grass 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 giant feather grass?
Giant feather grass comes from Iberian Peninsula, Morocco. These North American natives come closest to doing its job:
- Deer grass: the same job in a bed and the same colour; 2½ ft shorter, 4 in wider.
- Switchgrass 'Cloud Nine': the same job in a bed and the same size; flowers early August to early October, pink, not tan.
- White false indigo: the same job in a bed; 2½ ft shorter, flowers late May to late June.
Matched the way the planner's Swap button matches plants: the same job in a bed, then size, then flowering time.
Do deer eat giant feather grass?
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 giant feather grass?
Giant feather grass is over by early August. These start as it finishes and carry the same spot on, so it never goes flat:
- Switchgrass 'Northwind': from early August to early October, 5½ ft tall.
- Little bluestem 'Standing Ovation': from early August to mid September, 3½ ft tall, to stand in front of it and cover its fading stems.
- Lilyturf: from early August to mid September, 16 in tall, to stand in front of it and cover its fading stems.
What does giant feather grass look like in winter?
Giant feather grass 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 giant feather grass good for bees and butterflies?
Giant feather grass is visited by songbirds.
In these guides
- Pet-safe plants for a sunny border
- Plants that feed garden birds
- Tall perennials and grasses for the back of a border
- Silver and grey-leaved plants
Every fact on record
- Type
- Grass
- Size
- 6½ ft (200 cm) tall, 3½ ft (100 cm) wide
- Plant
- 3 ft (90 cm) apart
- Height class
- Very tall (5 to 6½ ft)
- Place in the bed
- Back, or further forward: it is airy enough to see through
- Flowers
- Mid June to early August; airy sprays; tan
- Leaves
- Fine texture, semi-evergreen; grey-green
- Shape
- Mounding, clumping
- Hardy in
- USDA zones 5 to 8
- Light
- Full sun
- Soil
- Lean, dry and sharply drained
- Water
- Low
- Feeding
- None needed
- Family
- Poaceae
- Comes from
- Iberian Peninsula, Morocco
- Attracts
- Songbirds
- Stands up to
- Deer, 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.