Orchid primrose

Questions about orchid primrose

Does orchid primrose need sun or shade?

Orchid primrose grows in 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 moist to wet soil, rich in organic matter, and plenty of water.

What zones does orchid primrose grow in?

USDA zones 5 to 8. It is hardy to zone 5, which means it survives winter nights down to about −10 °F (−23 °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 orchid primrose flower in my zone?

In zone 5 it flowers mid June to mid July. 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 orchid primrose be planted?

8 in (20 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 10 in (25 cm), so a group knits into one patch.

It grows 16 in (40 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.

How many orchid primrose plants do I need?

At 8 in apart, set out in staggered rows:

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

In a mixed border, plant it as one at a time, repeated along the bed at intervals; a slender one reads better as a clump of three.

In the bed above, the planner used five in five groups.

Is orchid primrose poisonous to dogs and cats?

Yes: mild toxicity to dogs, cats and horses. Can cause mild vomiting in pets if eaten.

Rated from the ASPCA. Where references disagree, the more cautious rating is used.

Is there a pet-safe plant like orchid primrose?

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

• Blue-eyed grass: the same size; an edging, not an accent, flowers mid May to late June.
• Horned violet: the same colour; an edging, not an accent, 10 in shorter.
• Shooting star: the same size; a drift, not an accent, 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.

What flowers after orchid primrose?

Orchid primrose is over by mid July. These start as it finishes and carry the same spot on, so it never goes flat:

• Lilyturf: from early August to mid September, 16 in tall.
• Black-eyed Susan: from mid July to mid September, 24 in tall.
• Japanese anemone: from mid August to early October, 3 ft tall.

What does orchid primrose look like in winter?

Orchid primrose 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.