Sweet woodruff

Questions about sweet woodruff

Does sweet woodruff need sun or shade?

Sweet woodruff grows in part shade (2 to 4 hours of sun, mostly in the morning) and shade (less than 2 hours of direct sun, or bright dappled light). It is one of the few that also put up with deep shade.

It wants soil that stays evenly moist, of average fertility, and a good soak in dry spells.

What zones does sweet woodruff grow in?

USDA zones 4 to 8. It is hardy to zone 4, which means it survives winter nights down to about −20 °F (−29 °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 sweet woodruff flower in my zone?

In zone 5 it flowers early May to early June. As a spring flower it moves about a week for every zone: earlier where it is warmer, later where it is colder.

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 sweet woodruff 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 8 in (20 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.

How many sweet woodruff 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 26 in six groups.

Is sweet woodruff 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 sweet woodruff?

Sweet woodruff comes from North Africa, Asia, Europe. These North American natives come closest to doing its job:

• Creeping woodland phlox: the same job in a bed, the same size, the same flowering time and the same colour; medium leaves, not fine, wants average soil.
• Foamflower: the same job in a bed, the same size, the same flowering time and the same colour; medium leaves, not fine.
• Woodland strawberry: the same job in a bed, the same size and the same colour; flowers early May to late August, medium leaves, not fine.

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

Do deer eat sweet woodruff?

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 sweet woodruff spread?

It spreads sideways, by runners or roots; the risk of it taking over is moderate. Spreads by creeping roots to form a carpet in moist shade. Easy to pull, but it will wander into its neighbours.

What flowers after sweet woodruff?

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

• Lady's mantle: from late May to early July, 18 in tall.
• Astilbe: from late June to mid July, 24 in tall.
• Cranesbill 'Rozanne': from early June to early October, 18 in tall.

What does sweet woodruff look like in winter?

Sweet woodruff 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.