Cerastium Tomentosum [Ker-RAS-tee-um Toh-men-TOH-sum] belongs to Caryophyllaceae family and is native to Europe and western parts of Asia.
This herbaceous flowering plant is typically distinguished from the rest of its genus-species by its felty or tomentose foliage.
Known by its common name, Snow in Summer, this plant looks stunning even when it is not blooming.
It produces a beautiful white flower color from May to June.
The abundance of white blooms which sprouts in this plant give resembles a blanket of snow, hence the common name.
This plant also has other common names, including:
- Wooly Mouse-Ear Chickweed
- Snow Plant
- Jerusalem Star
Cerastium Tomentosum Care
Size & Growth
This evergreen perennial grows around 5” – 11” inches tall.
It is rather dense, and its oval-shaped leaves are about 1” inch long.
The leaves are covered with entangled, frizzy, slivery, and silky hair.
This plant quietly grows all through the year and during April and May, it reaches its flowering cycle’s peak.
Flowering and Fragrance
During the blooming season, the foliage of this plant is completely covered with dense white flowers.
The flowering might also happen in small quantities during the summer season.
The flowers quickly blossoms during spring and cover the ground, spilling over low walls and flowing around rocks.
The flowers are silvery gray and star-like.
Gray foliage color.
Light & Temperature
The snow plant loves to be in the sun. It also tolerates partial or partial shade, but it is best to place in full sun for optimal growth rate.
During its germination process, it is best to keep this plant at 68° degrees Fahrenheit (20° C).
After germination, it grows well in temperatures between 68° – 77° degrees Fahrenheit (20° – 25° C).
United States hardiness zone 3 – 7 (USDA Zone).
Watering and Feeding
This plant is not drought-adapted and needs moisture regularly for consistent growth.
However, excessive water results in rotting. This plant is heat tolerant, so it is still able to grow in dry soil.
Feed snow in summer with high nitrogen fertilizer while planting, which gives this plant a good start.
Switch to a phosphorus fertilizer when bloom time is near.
Soil & Transplanting
Cerastium Tomentosum grows ideally in poor, yet well-drained soil type.
Opt for a loose soil which has good drainage to help this plant grow properly.
The soil must be kept moist while germinating.
Grooming and Maintenance
This plant is rather simple to grow and look after. Cut it back a few inches once the bloom period has passed.
Mow or shear back past flowers which have faded to encourage new growth. It should be divided after three years for fresh planting.
Cuttings should be taken during the early summer season in case of a higher requirement of plants.
Drought tolerant once matured.
How to Propagate Snow In Summer
Propagation of this plant is done with the help of seeds.
Snow in summer is seeded directly in the garden, or is also seeded indoors to transplant when needed.
It is best to sow the seeds during the early growing season and lightly cover with ⅛ inch of seas starting soil or fine garden soil.
The germination process of seeds is long and typically requires at least three weeks.
It is recommended to opt for seedling germination mat for indoor planting.
Propagation is also done through cuttings or plant division.
Cuttings should always be done during the late spring season.
It is ideal to space the plants 12” – 24” inches apart, so they have sufficient space to grow and spread.
These plants typically spread like a loose mat and fill out the empty spaces between the plants.
Once this plant reaches maturity, it quickly spreads around 12” – 18” inches wide.
Cerastium Pest or Diseases
If the snow in summer is placed under a well-shaded location or in high humidity climate, it will start damping off.
Similarly, if this plant is grown in prolonged wet soils or poor soil drainage, it might experience a severe rotting issue.
Cerastium Tomentosum is often a short-lived plant, which means dead patches start emerging after a few years.
The snow plant is invasive and spreads well beyond the garden space intended.
Ideally, the spread of this plant is control by utilizing border edging which should be dug about 3” – 5” inches below the soil surface.
Jerusalem Star Uses
This plant is used as ground cover in sunny areas.
It is a horticultural plant, perennial, rocky, mat-forming dense silver carpets.
It looks stunning when used as a bulb cover, edgings, in cottage gardens, border fronts, rock gardens, or dry stone walls.
It is ideally used in landscape design and is famous as border plantings.
It is also used for cascading over walls and banks to enhance the beauty of the garden.
Even before blooming, the silver-grey foliage of this plant looks stunning among other plants.