How to Grow Parnassia Plants

Guide to Growing Grass of Parnassus and Bog-Star

Parnassia is a hardy perennial that reaches from 20 to 45 cm in height.

They bloom in the summer, carrying white saucer shaped flowers. It has attractive heart shaped leaf foliage.

One of the common names for Parnassia is Grass of Parnassus.

Parnassia palustris
Parnassia palustris by DenaliNPS.

Growing and Care Guide

  • Common Names: Grass of Parnassus, Bog-Star
  • Life Cycle: Hardy perennial.
  • Height: 8 to 24 inches (20—60 cm).
  • Native: Northern Hemisphere (alpine and mountain regions).
  • Growing Region: Zones 3 to 5 (Parnassia palustris to zone 9).
  • Flowers: Summer.
  • Flower Details: Upturned saucers. Five-petaled. White. Green veins.
  • Foliage: Green. Cordate. Up to 4 inches (10 cm).
  • Sow Outside: Surface. Late summer using fresh seed. Germination time: one to six months. Seeds should be sown into flats. Sink the flat into the ground in an area that offers shade, preferably close to a wall that faces north. Provide a glass/plastic covering. Keep an eye on the flats to ensure that the soil remains moist and to check if seedlings have emerged. Once plants have developed five true leaves, repot into peat pots. Relocate pots to a lightly shaded area. Water from below to keep moist. Transplant to their final location in autumn. Spacing: 7 to 8 inches (27—20 cm).
  • Requirements and care: Full sunlight or light shade. Poor drainage/Swampy. Soil pH 6—7. Rich soil. Regular watering to maintain soil moisture. Spring mulch. Propagate: by dividing once blooming has completed.
  • Family: Celastraceae.
  • Closely Related Species: Bittersweet plants and Staff Vines.
  • Miscellaneous: The name of the plant was given by Mt. Parnassus farmers in Greece, whose cattle were very fond of eating it.

How to Grow Grass of Parnassus

When growing Grass of Parnassus from seed it is best to grow outdoors in its final location. The plants like to grow in swampy (or very moist) conditions and are able to grow in a sunny or lightly shaded part of the garden. Ideally the soil should be ever so slightly acidic to neutral (pH 6 to 7) and rich.

The Parnassia seeds should be sown on the surface of flats using fresh seed at the end of summer. The flats should then be sunk into a shady part of the garden.

Germination can take from one to six months. Once the Grass of Parnassus seedlings have grown to a stage where they have five leaves they should be transplanted into peat pots and relocated to an area of light shade; the pots should be watered from below.

In the autumn the plants can be transplanted into the garden at about 15 to 20 cm apart.

Caring for Parnassia

It is easy to look after Parnassia, they like the soil to be moist or swampy so water regularly. Additionally the plants should be mulched in the spring to keep the plants cool.

It is recommended to divide the plants every three or four years to maintain vigour. If you require more grass of Parnassus plants then they can be propagated by division immediately after flowering has finished.

I hope that you enjoyed this guide on how to grow Parnassia plants. You may also enjoy the following Gardener's HQ growing guides: How to grow Euonymus-fortunei and Dioscorea plants.