Snow-in-summer is a perennial flower that gets its common name from its blooming habit. It blooms profusely in the early summer, with a blanket of notched pristine white flowers that suggest a fresh snowfall. But the name does not tell the whole story. This ground cover, a member of the carnation family, is just as admired for its delicate, woolly, silver leaves as for its charming flowers. These leaves spread a mat of foliage from which flower stems rise in late spring/early summer. Snow-in-summer spreads quickly by reseeding and by producing runners when grown in favorable conditions. Newly germinated seedlings should be planted in early spring.
Moderate-growing snow-in-summer makes an excellent ground cover for dry, sunny areas. It is deer resistant and often used in rock gardens or as a cover to fill in after spring bulbs are finished. It also can be used to fill in pockets in stone walls.
|Botanical Name||Cerastium tomentosum|
|Common Name||Snow-in-summer, silver carpet, mouse ear, chickweed|
|Plant Type||Herbaceous perennial|
|Mature Size||6-2 in. tall, 9-12 in. wide|
|Sun Exposure||Full sun|
|Soil Type||Dry, sandy, well-draining|
|Hardiness Zones||3-7 (USDA)|
Snow-in-summer are perennial flowers that perform superbly well along the coast of Maine (United States). This fact suggests that they are reasonably salt-tolerant and that they enjoy the cooling breezes coming off the Atlantic, which moderate summertime temperatures.
This plant spreads quickly, so plant them at least 1-foot apart to stave off overcrowding. To avoid rampant spreading, shear the flower stems off after flowering is complete and before seeds can be dropped. (Carefully clean up what you've cut away, just in case some of those seeds are ready to do their thing!) Some cultivars are more compact and less likely to spread uncontrollably.
While considered fussy in some regions, in other areas snow-in-summer has a reputation for being a fairly invasive plant. Be careful to keep this plant within its boundaries and not allow it to naturalize into surrounding areas. It takes vigilance, but it's worth the effort.
This plant prefers full sun conditions: Snow-in-summer can develop fungal problems in the shade. You can avoid this by giving it the light it needs.
Snow-in-summer thrives in well-draining soil but adapts to most soil types except those that are damp and poorly draining which can cause root rot.
This plant prefers relatively dry conditions and has a good tolerance for short periods of drought. It will not do well where frequent rainfall or watering keeps the ground soggy.
Temperature and Humidity
Snow-in-summer is suitable for growing in USDA hardiness zones 3-7. This is a plant that likes relatively cool, dry summers, and it will be very short-lived if planted in hot, humid climates.
This plant generally does not need any type of special feeding; it prefers rather poor soils. If you feel your snow-in-summer isn't performing the way you'd hoped, a fertilizer that's high in phosphorous, right before your plant blooms, might just be the thing.
After they have dumped their "snowfall" of white blooms in early summer, trim away the faded blooms and some of the foliage to keep snow-in-summer plants looking attractive for the rest of the summer. Remember, snow-in-summer is grown as much for the glorious silvery carpet of the foliage as for their attractive flowers. Trimming can be done easily with a lawnmower set high or with a string trimmer.
Where desired, the roots of snow-in-summer can be divided and replanted to create new plants. Division is best done immediately after the plants have concluded blooming. Self-seeded volunteers can also be dug up and transplanted.
How to Grow Snow-in-Summer From Seed
It's also super-easy to grow snow-in-summer from seed. Simply sow the seed directly into your flowerbeds in early spring, and loosely cover with about 1/8-inch garden or potting soil. Germination should occur in two to three weeks; know that new plants won't bloom until their second year.
Varieties of Snow-in-Summer
- 'Silberteppich': features a more compact flowerhead and is slower spreading
- 'YoYo': produces abundant blooms
- ‘Silver Carpet’: offers frosty, white foliage, and is a more compact plant
- 'Columnae': boasts features similar to 'Silver Carpet' but it is a lower plant, forming 4-inch mounds
- 'Melaleuca decora': has puffy, frilly white flowers and long, narrow leaves
- 'Bridal-wreath Spiraea': offers pom-pom like flowers and attracts butterflies
High humidity or too much shade can foster damping-off disease and other fungal problems. Root rot can be a problem in soil that is too moist. Keeping your snow-in-summer in a drier area, with well-draining soil, will solve these problems.