European columbine

Questions about European columbine

Does European columbine need sun or shade?

European columbine 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 a good soak in dry spells.

What zones does European columbine grow in?

USDA zones 3 to 8. It is hardy to zone 3, which means it survives winter nights down to about −30 °F (−34 °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 European columbine flower in my zone?

In zone 5 it flowers mid May to late 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 European columbine be planted?

14 in (35 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 2½ ft (75 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.

How many European columbine plants do I need?

At 14 in apart, set out in staggered rows:

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

In a mixed border, plant it as a group of three or five, with a second group further along in the other number.

In the bed above, the planner used five in one group.

Is European columbine poisonous to dogs and cats?

Yes: mild toxicity to people, dogs and cats. Seeds and roots can cause stomach upset if eaten, and the sap may irritate skin.

Is there a pet-safe plant like European columbine?

These come closest to doing what European columbine does, and no toxicity is recorded for them:

• Balloon flower: the same job in a bed; 6 in shorter, flowers early July to mid August.
• Coneflower 'White Swan': the same job in a bed and the same size; flowers early July to early September, white, not purple.
• Rose turtlehead: the same job in a bed and the same size; flowers mid August to late September, pink, not purple.

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

Will European columbine spread?

It seeds itself about; the risk of it taking over is moderate. Self-seeds freely, and seedlings vary in colour. Cut the stems before the seed ripens to limit them.

What flowers after European columbine?

European columbine is over by late June. These start as it finishes and carry the same spot on, so it never goes flat:

• Astilbe: from late June to mid July, 24 in tall.
• Black-eyed Susan: from mid July to mid September, 24 in tall.
• Butterfly weed: from late June to early August, 24 in tall.

What does European columbine look like in winter?

European columbine 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.