Big bluestem
Andropogon gerardii
A prairie grass that stands upright right through winter, so long as the soil stays lean — feed it and it falls over.
- Type
- Grass · Perennial
- Botanical family
- Mixed / other
- Foliage color
- Blue-green
- Sunlight
- Full sun, and nothing less.
- Watering
- Drought-tolerant once it has its roots down.
- Feeding
- Do not feed it.
- Frost tolerant
- Yes
- Flowering
- August
- Pruning
- Cut back to 15 cm in late February.
- Apr–Aug Spring Growth
- Aug–Oct Flowering
- Oct–Dec Growing
- Dec–Dec Winter Dormancy
- Jan–Apr Winter Dormancy
- Plant spacing
- 2 ft 6 in
- In-row spacing
- 2 ft 6 in
- Between rows
- 3 ft 1 in
- Square-foot density
- Not suited to SFG
- Root system
- A dense fibrous mat
- Working depth
- 24 in–6 ft
- Can reach
- 8 ft down where the soil allows
- Spread
- 2.5–5 ft across, about 1–2× the width of the plant
- Shallowest pot
- 12 in of soil
Thousands of fine roots knit the top of the soil into a turf, which is what holds a bank together and what makes an established clump so hard to lift. Prairie grasses send a few roots far below the mat as well.
A tallgrass prairie species, and the roots are most of the plant: two metres of them, which is what built the deep black soils of the plains and what makes an established clump effectively drought-proof.
Figures recorded for Big bluestem itself. 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.
- Leaf spot Leaf spot.
- Rust Rust in humid air.
- Lodging — rich soil buys height the stems cannot hold up.
Echinacea, Rudbeckia, Liatris, Ratibida
Grasses, like this one.
The Cottage Garden Companion — the gardener's herbarium at cottagegardencompanion.com