Leadwort

Questions about leadwort

Does leadwort need sun or shade?

Leadwort 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 ordinary well-drained soil, of average fertility, and little watering once settled. Once settled in, it stands drought.

What zones does leadwort grow in?

USDA zones 5 to 9. It is hardy to zone 5, which means it survives winter nights down to about −10 °F (−23 °C).

Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.

When does leadwort flower in my zone?

In zone 5 it flowers early August to early October. As a summer flower it moves about half a week for every zone: earlier where it is warmer.

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 leadwort be planted?

12 in (30 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 18 in (45 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 leadwort plants do I need?

At 12 in apart, set out in staggered rows:

• 12 to fill 10 square feet (about 1 m²)
• 11 for a single row 10 ft (3 m) long
• 38 to fill a 4 × 8 ft bed on its own

In a mixed border, plant it as threes and fives, along the front and just behind it.

In the bed above, the planner used 11 in three groups.

Is leadwort 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 leadwort?

Leadwort comes from North-Central and Southeast China. These North American natives come closest to doing its job:

• Creeping woodland phlox: the same job in a bed, the same size and the same colour; flowers late April to late May.
• Woodland strawberry: the same job in a bed and the same size; flowers early May to late August, white, not blue.
• Robin's plantain 'Lynnhaven Carpet': the same job in a bed; 4 in shorter, flowers early May to late May.

Matched the way the planner's Swap button matches plants: the same job in a bed, then size, then flowering time.

Do deer eat leadwort?

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.

Will leadwort spread?

It spreads sideways, by runners or roots; the risk of it taking over is moderate. Spreads steadily by underground stems into a dense mat. It is easy to contain with an edge.

What flowers after leadwort?

Leadwort is over by early October. These start as it finishes and carry the same spot on, so it never goes flat:

• Japanese onion 'Ozawa': from early October to early November, 10 in tall.
• Chrysanthemum 'Sheffield Pink': from late September to early November, 2½ ft tall.
• Tatarian aster 'Jindai': from early October to early November, 4 ft tall.

What does leadwort look like in winter?

Leadwort dies down to the ground and there is nothing to see until spring. The old stems can be cut in autumn, or left until spring as shelter for overwintering insects.

Is leadwort good for bees and butterflies?

Leadwort is visited by pollinators, butterflies and hummingbirds.