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 is a clump-forming perennial from the rose family, grown for the deep red, bottlebrush flower heads that rise on slender stems above its ferny foliage. It belongs to a group of edible burnets, and its smaller cousin, salad burnet, is the one cooks reach for. This taller species earns its place as an ornamental, holding its color through early summer.
It asks very little. Give it full sun and steady moisture and it settles into zones 4 through 8 without fuss, shrugging off pests and disease. The one habit to watch is its eagerness to scatter seed, which can fill a bed with young plants if you let the flowers ripen.
Plants reach 2.5 to 3 feet (76 to 91 cm) tall and spread into a tidy clump. The wiry stems can lean after rain, so a little support keeps the display upright. Beyond that, it's about as low-maintenance as a flowering perennial gets.
Care
The short version: full sun and consistently moist, well-drained soil, with stakes for the tall stems and deadheading to keep the self-seeding in check.
Light
Plant great burnet in full sun for the sturdiest stems and the best flowering. It will take partial shade, but plants grown in too much shade turn weak and leggy and lean over more.
Water
Keep the soil consistently moist and don't let the root zone dry out, especially through summer heat. It's happy in damp ground and even tolerates moist sites, so check it every few days and water before the soil goes dry.
Soil
Average, medium-moisture, well-drained soil suits it fine, with no need to chase a particular pH. Work in some compost on poor ground, but avoid making the soil too rich, which only grows soft, floppy stems.
Temperature
This is a tough, cold-hardy perennial for zones 4 through 8, riding out winters down to about -29°F (-34°C) and summers up to roughly 86°F (30°C). No special protection is needed across that range.
Humidity
Ordinary outdoor humidity is all it asks, so there's no figure to aim for. What matters far more is steady soil moisture, since dry roots show up as browning leaf edges long before the air does.
Feeding
Feed lightly in spring, once a season, with a balanced general-purpose fertilizer or a topdressing of compost. That's plenty on average garden soil, and going heavier just encourages weak, leggy growth.
Pruning
Cut back the spent flower stems to hold down self-seeding, then cut the whole plant to the ground in late fall or early spring. Stake the taller stems early so they don't sprawl after rain or wind.
Repotting
This is a garden perennial that's rarely lifted, growing best left in place to form a clump. Divide it only when the crowd thins the flowering or the center of the clump starts dying out.
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 room so the airy stems have space to show.
When to plant
Great burnet runs on the seasons. Start seed indoors in late winter to early spring, set plants out after the last frost, and the dark red flower spikes open from May into early summer, lasting later on some forms.
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 free of serious pests and disease, so its few problems trace back to siting and water. Read the early signs below and a quick fix keeps the planting looking its best.
Browning along the leaf edges and tips
Browning at the margins almost always means the soil has dried out, and it gets worse through hot, dry stretches of summer. This plant wants its roots damp. Water to keep the soil evenly moist and lay down mulch to hold that moisture, and the new growth comes back clean.
Fix:
- Water to keep soil evenly moist
- Apply mulch to conserve soil moisture
Tall flower stems flopping or bending over
Those wiry stems carry their dark flower heads high, and top-heavy growth sends them sprawling after a hard rain or a gust of wind while the crown below stays fine. Rich soil or too much shade only makes the stems softer and leggier. Set stakes or a grow-through support early in the season and keep the plant in full sun so it grows sturdy from the start.
Fix:
- Install stakes or grow-through supports early in the season
- Site in full sun for sturdier stems
Volunteer seedlings popping up around the clump
Great burnet self-seeds freely, so spent flower heads left to ripen will scatter young plants across the bed. It is easy to manage once you know the cause. Deadhead the flowers before the seed sets, and pull any volunteers you don't want while they're still small.
Fix:
- Deadhead spent flowers before seed sets
- Remove volunteer seedlings by hand
Toxicity
Good news for households with pets and children: great burnet is not toxic. It belongs to a group of culinary burnets, and the closely related salad burnet is cleared as non-toxic to cats, dogs, and horses, so a stray nibble is nothing to worry about.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Nothing to worry about here. A cat that nibbles a leaf or flower head won't run into any toxin from this plant.
Dogs None
Safe around dogs. The genus is grown and eaten by people, and a curious dog can mouth the foliage without harm.
Horses None
No toxin reaches horses from great burnet, and its close salad burnet cousin is cleared as non-toxic for them.
Rabbits Safe
Rabbits can graze the leaves freely. This is a culinary burnet with no reported toxicity to small grazers.
Livestock Safe
Cattle, goats, and sheep are in no danger from it, since the foliage carries no toxic compounds.
Birds Safe
Backyard birds and poultry can peck at the plant without any risk from a toxin.
People Safe
Safe for people. Burnets are a culinary group, and the young foliage has long been used in the kitchen.
No special handling precautions are required; the plant is not reported to be toxic.
Varieties
A couple of named selections give you the same dark flowers in a tidier or taller package. These are the ones worth seeking out.
Tanna
A compact selection that tops out near 12 inches (30 cm), carrying deep maroon-red bottlebrush flower heads on upright stems.
Red Thunder
A taller, strongly branching form with deep burgundy-red flowers that bloom from midsummer into late summer.
How to propagate
Great burnet is easy to multiply, whether you split an established clump or simply let it sow itself.
DivisionEasy
Spring or early fall · One growing season
The simplest way to make more is to divide an established clump in spring or early fall. Lift the whole crown, cut it into sections with healthy roots, and replant into prepared, moisture-retentive soil. Each division settles in over a single growing season.
SeedEasy
Spring · One to two seasons to flowering size
Great burnet self-seeds freely, so seed is just as easy. Sow collected or bought seed in spring in average soil and it comes up readily. Give the young plants one to two seasons to reach flowering size.
Myths
Great burnet is the same plant as culinary salad burnet.
They share a genus and a common name, but they aren't the same plant. Great burnet is the taller ornamental perennial grown for its dark red flower spikes, while salad burnet (Sanguisorba minor) is the smaller, cucumber-flavored herb you cut for the kitchen. Check the species name before you plant for flavor.