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How to Grow Polyantha Primrose – Polyantha Primula

Primrose Primula vulgaris

Polyanthus primrose is a tender semi-evergreen hybrid perennial that produces single blossoms or umbels of up to 20 flowers in spring. Polyanthus primroses are often called English primroses.

Polyantha or English primroses are widely hybridized and cultivated. There are many cultivars and strains widely available at garden centers and nurseries. Polyantha primroses are often listed as the Polyanthus Group of primroses and also as Primula x poloyanthus. Polyanthus primroses are crosses between various hardy primroses.

Hybrid polyanthus primroses along with the primrose species Primula vulgaris are often called English primrose. There is a separate entry on this website for Primula vulgaris and also for Primroses in general.

Polyantha primroses form low 8 to 12 inch (20-30cm) wide rosettes of evergreen to semi-evergreen, rough-textured leaves. In mid-spring, clusters of showy 1- to 2-inch-wide flowers bloom on 6-inch (15cm) tall stems in a wide range of colors including pale to deep yellow, red, orange, violet-blue, white, and pink–often with yellow eyes.

Polyantha primroses are hardy to Zone 3. Florist’s types are usually less hardy.

Polyantha primrose in garden
Polyantha primrose

Get to Know Polyantha Primrose

  • Plant type: Perennial usually grown as an annul
  • Growing Zones and range: Zones 5 to 8; grow as an annual or perennial depending on the climate; grow as an annual in Zones 3 to 7
  • Hardiness: Hardy to Zone 5, -20°F (-29°C)
  • Height and width: 6 to 12 inches (15-3-cm) tall; 8 to 12 inches (20-30cm) wide
  • Flowers: Brilliant large flowers in clusters; colors include yellow, red, blue, white, purple
  • Bloom time: Winter blooms in mild winter regions; early spring in most regions; bloom time is about 6 weeks; summer in cool-summer regions.
  • Uses: Winter and early spring bedding
  • Botanical name: Primula x polyanthus
  • Common name: Polyantha primrose
  • Family: Primulaceae
  • Origin: Bogs and marshlands in the Northern Hemisphere

Where to Plant Polyantha Primrose

  • Plant polyantha primrose in full sun in Zones 3-6; plant in light shade in Zones 7-10.
  • Grow polyantha rose in humus-rich, moisture-retentive but well-drained soil.
  • Primroses grow best in cool climates and regions with cool summer. In warm summer regions, grow primroses in a spot that is shaded during the warmest part of the day.
  • Growing indoors, give primroses a light, cool, airy windowsill.
  • The optimal soil pH for primroses is 6.5.

Primrose Uses and Companions

  • Primroses can be used in beds and borders.
  • Plant primroses in a naturalistic setting, cottage garden, or along a stream or bog.
  • Good garden companions for English primrose include Aquilegia, Dicentra, Epimedium, Mertensia Polygonatum.
Primula primrose
Primula primrose

When to Plant Polyantha Primrose

  • Set polyantha primrose in the garden when the soil is workable in spring. In mild-winter regions set plants in the garden in winter.
  • Plant in early spring in Zones 3-7. Plant in late autumn in Zones 8-10 for winter bloom.
  • Start primroses indoors in early spring for transplanting out in late spring.

Planting and Spacing Polyantha Primrose

  • Start primroses indoors in a sterile seed starting mix. Sow seeds 1/8 inch deep or press the seed into the medium.
  • Transplant seedlings into separate small pots when 2 true leaves have appeared. Repot into a 5 inch (13cm) pot when the roots are full.
  • Set primroses in the garden when plants are fully rooted after hardening off.
  • Space polyantha primroses 8 to 12 inches ( 20-30cm) apart.

How to Water and Feed Polyantha Primrose

  • Give polyantha primroses ample moisture; keep the soil evenly moist but not wet. Water primrose regularly during dry spells.
  • Fertilize polyantha primrose with slow-release, all-purpose fertilizer added to the soil at planting time.
Polyanthus Primrose
Polyanthus Primrose

Polyantha Primrose Care

  • Discard spent plants when hot weather arrives.

Polyantha Primrose Pests and Diseases

  • Primroses are susceptible to aphids, spider mites, weevils, and slugs.
  • Diseases that attack primrose include gray mold, root rot, rust, and leaf spots.
  • To avoid disease, avoid wetting flowers and foliage.

Polyantha Primrose Propagation

  • Polyantha Primrose seeds germinate in 7 to 15 days at 60° to 65°F (15-18°C). Plants will be large enough for transplanting in 25 to 35 days. Flowers usually appear 20 to 25 weeks after sowing.

Polyantha Primrose Cultivars

  • There are many strains and cultivars of polyantha primrose. Large-flowered strains include Clarke’s, Concorde, Barnhaven, Pacific, Santa Barbara.

Also of interest:

How to Grow Primrose

Portulaca

How to Grow Portulaca — Moss Rose

Primrose vulgaris

How to Grow Primula vulgaris–English Primrose