Rock rose 'Wisley Primrose'
Helianthemum 'Wisley Primrose' ·
A spreading, evergreen mat of grey-green leaves, covered for weeks in early summer with soft primrose-yellow flowers like tiny single roses.
- Size
- 10 in tall, 24 in wide
- Zones
- 5 to 8
- Light
- Full sun
- Flowers
- Late May to mid July
- Pets
- Not checked
- Job in a bed
- Carpet
A bed built around rock rose 'Wisley Primrose'
The planner designed this bed around rock rose 'Wisley Primrose' when this page was made: a 12 × 6 ft (3.7 × 1.8 m) English border in zone 6, full sun. It chose the other plants from the 715 that suit those conditions and its dry soil, and says below why rock rose 'Wisley Primrose' stands where it does.
The plants
- 1 Rock rose 'Wisley Primrose' × 9, yellow
- 2 Sea thrift × 8, pink
- 3 Little bluestem 'The Blues' × 3, tan
- 4 False sunflower 'Summer Nights' × 3, yellow
- 5 Silver sage × 1, silver leaves
- 6 Butterfly weed × 3, orange
- 7 Star of Persia × 3, purple
- 8 Schubert's allium × 3, pink
Why this plant
- The only open bowls. The others are globes, spires, daisies and others. Shape reads at a distance, where colours blur.
- A classic partner for sea thrift. Both are on this plan. A pairing gardeners have proved outranks a general rule.
Why here
- Under the taller plants. It runs back between them as living mulch: there its job is to cover the soil, not to be looked at.
- 9 plants in 2 groups (5 and 4). Seen again further along, the same plant ties the bed together.
- Beside sea thrift. A recognised partner: the planner puts such plants together where it can.
Why now
- In flower for 7 weeks. From late May to mid July.
- Part of the bed's peak. With sea thrift, star of Persia and Schubert's allium in late May: 4 kinds at once. No week has more.
- One of two evergreens. They are what the bed has to show from November to March.
Planned as an English border: 5 of the 6 groups (83%) are drifts, longer along the bed than they are deep. For contrast, the bold leaves of silver sage sit beside the fine leaves of rock rose 'Wisley Primrose'. The most in flower at one time is 4 kinds, from late May.
The planner's own design check: 11 Excellent, 6 Good. It flags one thing to watch: Nothing on this plan is highly poisonous or an aggressive spreader.
Open this bed in the planner Change its size, the sun or the style, move plants about, or swap one for another.
Where rock rose 'Wisley Primrose' goes in a border
At 10 in it belongs at the front of a bed. In the planner's ten height classes it is low (6 to 12 in).
Its job: carpet. A groundcover planted in threes and fives to cover the soil: along the front, and just behind it.
Each flower lasts a day and there are hundreds. It thrives on a hot, dry, limy bank where little else will. Trim it after flowering to keep it dense.
- Dry, sunny banks
- Wall tops and rock gardens
- Evergreen edging in gravel
What to plant with rock rose 'Wisley Primrose'
Plants recorded as good partners for it, and what each pairing does:
- English lavender 'Hidcote': purple against yellow, opposite each other on the colour wheel, in flower together for four weeks; spires rising out of its mound; tall enough (18 in) to stand behind it.
- Sea thrift: in flower together for three weeks, from late May; happy in the same dry soil.
- Blue fescue: its blue-green leaves are a setting for the flowers, before and after; happy in the same dry soil.
Questions about rock rose 'Wisley Primrose'
Does rock rose 'Wisley Primrose' need sun or shade?
Rock rose 'Wisley Primrose' grows in full sun (6 or more hours of direct sun a day).
It wants dry, sharply drained soil, on the lean side, with no feeding, and little watering once settled.
What zones does rock rose 'Wisley 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 rock rose 'Wisley Primrose' flower in my zone?
In zone 5 it flowers late May to mid July. As a spring flower it moves about a week for every zone: earlier where it is warmer, later where it is colder.
| Zone 5 | Late May to mid July |
|---|---|
| Zone 6 | Late May to mid July |
| Zone 7 | Mid May to early July |
| Zone 8 | Early May to early July |
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 rock rose 'Wisley Primrose' be planted?
18 in (45 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 24 in (60 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 rock rose 'Wisley Primrose' plants do I need?
At 18 in apart, set out in staggered rows:
- 5 to fill 10 square feet (about 1 m²)
- 7 for a single row 10 ft (3 m) long
- 17 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 nine in two groups.
Is there a native plant like rock rose 'Wisley Primrose'?
Rock rose 'Wisley Primrose' is not native to North America. These North American natives come closest to doing its job:
- Woolly yarrow: the same job in a bed, the same flowering time and the same colour; 6 in narrower, not evergreen.
- Seaside daisy: the same job in a bed and the same size; flowers late May to late August, lavender, not yellow.
- Three-toothed cinquefoil: the same job in a bed and the same flowering time; 4 in shorter, 6 in narrower.
Matched the way the planner's Swap button matches plants: the same job in a bed, then size, then flowering time.
What flowers after rock rose 'Wisley Primrose'?
Rock rose 'Wisley 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.
- Ornamental onion 'Millenium': from mid July to late August, 18 in tall.
What does rock rose 'Wisley Primrose' look like in winter?
Rock rose 'Wisley Primrose' keeps its grey-green leaves all winter, so it is one of the plants that hold a bed together from November to March, when the perennials have gone.
More Helianthemum
- Rock rose Helianthemum nummularium
- Rock rose 'Henfield Brilliant' Helianthemum 'Henfield Brilliant'
In these guides
- Low plants for the front of a border
- Groundcover plants
- Evergreen perennials, ferns and grasses
- Silver and grey-leaved plants
Every fact on record
- Type
- Perennial (groundcover)
- Size
- 10 in (25 cm) tall, 24 in (60 cm) wide
- Plant
- 18 in (45 cm) apart
- Height class
- Low (6 to 12 in)
- Place in the bed
- Front
- Flowers
- Late May to mid July; open bowls; yellow
- Leaves
- Fine texture, evergreen; grey-green
- Shape
- Mat-forming, clumping
- Hardy in
- USDA zones 5 to 8
- Light
- Full sun
- Soil
- Lean, dry and sharply drained
- Water
- Low
- Feeding
- None needed
Not yet checked against an outside reference: its figures rest on general horticultural knowledge. Flowering times are for zone 5: later in colder zones, earlier in warmer ones. Toxicity and spread information is a general gardening guide, not veterinary or medical advice, and invasive status varies by region. If a person or pet eats a plant, contact poison control or a vet. Check your local invasive species list before planting anything with a spread warning.