Ornamental · Rosaceae
Great Burnet
Sanguisorba officinalis
Tall wands of dark red bottlebrush flowers that sway over the back of a damp, sunny border all summer.
Full sun
Every 3–7 days
USDA 4–8
2–3 ft · 0.8–0.9 m
Overview
Great burnet, Sanguisorba officinalis, brings real movement to the garden. Slim stems climb to 2.5 to 3 feet (76 to 91 cm) and break into dark red bottlebrush flower heads that dance over the back of a moist, sunny bed from late spring onward. It reads as airy and modern, and it earns its place fast.
This is a tough, cold-hardy perennial that asks for little once it settles in. Give it full sun and soil that stays evenly moist, and it returns year after year, spreading into a tidy clump of 2 to 3 feet (61 to 91 cm). Pollinators work the dark heads, and the upright form mixes beautifully with grasses and other damp-border plants.
Rated easy for good reason, it shrugs off serious pests and disease and rewards a light touch. Stake the tallest stems, keep the roots from drying, and snip spent blooms to rein in self-seeding. Do that and great burnet runs a long, dependable show.
Care
The short version: plant great burnet in full sun, keep the soil consistently moist, and skip the heavy feeding. Stake the tall stems early, cut back spent flowers to curb self-seeding, and divide only when a crowded clump starts to thin. It handles zones 4 through 8 and asks for very little once established.
Light
Aim for full sun, which gives the sturdiest stems and the strongest flowering. The plant takes partial shade in stride, but pile on too much shade and growth turns weak, leggy, and prone to leaning. Bright, open spots pay off every time.
Water
Keep the soil consistently moist and never let the root zone bake dry, especially through summer heat. This is a plant that loves damp ground and tolerates downright moist sites, so steady watering suits it well. Check the soil every few days and water before it dries, and it powers right along.
Soil
Plant into average, medium-moisture, well-drained soil and skip any fuss over pH; it is not picky there. Work compost into thin or poor ground to give roots something to grab, but go easy, since overly rich soil grows soft, floppy stems.
Temperature
This is a tough, cold-hardy perennial built for zones 4 through 8. It rides out winters down to about -29°F (-34°C) and takes summer warmth up to roughly 86°F (30°C) without complaint. No special protection is called for.
Humidity
Ordinary outdoor humidity is all it wants, so there is no target reading to chase. Steady soil moisture matters far more than the air, and dry roots tip their hand first: watch for browning leaf edges before you ever blame the humidity.
Feeding
Feed lightly and you will get the best of it. A single spring application of balanced general-purpose fertilizer, or a topdressing of compost, carries the plant through the season on average soil. Pour on more and you trade flowers for weak, leggy growth.
Pruning
Trim back spent flower stems to hold down self-seeding, then cut the whole plant to the ground in late fall or early spring for a clean restart. Stake the taller stems early in the season so a heavy rain or gust does not leave them sprawling.
Repotting
As a garden perennial, great burnet is rarely lifted and grows best left in place to build a clump. Divide only when crowding starts to thin the flowering or the center of the clump dies out, signaling it is time to rejuvenate.
Size & spacing
Expect a clump 2.5 to 3 feet (76 to 91 cm) tall with a spread of 2 to 3 feet (61 to 91 cm). Give each plant that much elbow room so the airy stems have space to wave without crowding their neighbors.
When to plant
Get a head start by sowing seed indoors from late winter to early spring, then move young plants outside once the last frost has passed. The dark red flower spikes open from May into early summer, and a few forms keep going later in the season.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: Late winter to early spring
- Plant: Spring after last frost
- Harvest: May to June (into late summer for some forms)
Hardiness
USDA hardiness zones: 4–8
Temperature: down to -34°C
Troubleshooting
Great burnet stays remarkably clean of serious pests and disease, so the handful of issues that crop up nearly always come back to where it sits and how wet the soil stays. Spot the early signs, apply a quick fix, and the planting keeps looking sharp.
Crisp brown rims creeping in on the foliage
Dry roots show up first at the leaf margins, so browning edges and tips usually mean the soil went thirsty during a hot, dry stretch. Steady moisture turns it around fast. Water to keep the ground evenly damp and lay down mulch, and fresh growth comes back clean and green.
Fix:
- Water to keep soil evenly moist
- Apply mulch to conserve soil moisture
When those tall blooming stems lean and tip
Great burnet sends up airy, top-heavy stems, and a strong rain or gust can knock the unsupported ones sideways while the crown keeps growing fine. Soil that runs too rich or a spot with too much shade pushes soft, stretched growth that bends easily. Slip supports in early and grow the plant in full sun, and those stems stand tall.
Fix:
- Install stakes or grow-through supports early in the season
- Site in full sun for sturdier stems
Surprise baby plants cropping up nearby
This perennial scatters seed happily, so spent flower heads left in place drop seed and spark a flush of young plants around the parent. Catch it early by snipping faded blooms before seed forms. Pull any volunteers you did not plan for, and the clump stays right where you want it.
Fix:
- Deadhead spent flowers before seed sets
- Remove volunteer seedlings by hand
Toxicity
Good news for animal households: great burnet is not toxic. It sits among the culinary burnets, and its close cousin salad burnet has been cleared as non-toxic to cats, dogs, and horses. A stray nibble is nothing to lose sleep over.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
A curious cat that bats at or chews a leaf has nothing to fear here, since no toxicity shows up for this burnet.
Dogs None
Dogs can sniff and sample the foliage without concern, as the plant carries no reported toxic effects.
Horses None
Horses grazing near a planting stay safe; nothing harmful has been recorded for them.
Rabbits Safe
Rabbits can nibble the leaves freely, with no toxic reaction to watch for.
Livestock Safe
Livestock browsing the plant face no known risk from it.
Birds Safe
Birds picking at seed heads or foliage come to no harm.
People Safe
People are clear too; this is a culinary burnet relative with no toxicity to flag.
No special handling precautions are required; the plant is not reported to be toxic.
Varieties
A couple of named selections deliver the same moody dark flowers in either a tidier or a taller package. Both are well worth tracking down.
Tanna
A neat, compact pick that holds to roughly 12 inches (30 cm), topped with deep maroon-red bottlebrush heads riding upright stems. Great for tucking into smaller spaces while keeping that signature dark color.
Red Thunder
A taller, freely branching form that throws up deep burgundy-red flowers from midsummer well into late summer. Pick this one when you want height and a long run of color at the back of the bed.
How to propagate
Multiplying great burnet could hardly be easier. Split an established clump or simply let the plant sow itself and pot up the volunteers.
DivisionEasy
Spring or early fall · One growing season
Division is the quick route. Lift the whole crown in spring or early fall, slice it into sections that each carry healthy roots, then replant into prepared, moisture-retentive soil. Every piece settles in over a single growing season.
SeedEasy
Spring · One to two seasons to flowering size
Since the plant sows itself so readily, seed is a breeze. Scatter collected or purchased seed in spring across average soil and watch it come up with little fuss. Young plants need one to two seasons to reach flowering size.
Myths
Great burnet and the salad burnet you cook with are one and the same plant.
They share a genus and a common name, yet they part ways from there. Great burnet is the taller ornamental perennial prized for its dark red flower spikes, while salad burnet, Sanguisorba minor, is the smaller, cucumber-flavored kitchen herb. Check the species name before you plant if flavor is what you are after.