Snow-in-Summer Plant Care: How to Grow the White Perennials

Snow-in-summer (Cerastium tomentosum) is a winter-hardy member of the Caryophyllaceae plant family that produces white flowers in late spring or early summer. Gardeners know this plant by other names, too, including silver carpet or mouse-ear chickweed. These common names stem from its white blooms and the fuzzy texture of its low-growing leaves.

Landscapers sometimes use snow-in-summer’s silvery-green foliage to frame more vibrant blooms in cottage gardens or as ornamental ground cover along pathways.

With their white flowers and silvery foliage, snow-in-summer plants can provide visual contrast in your landscaping or garden. Here are a few things to keep in mind if you want to grow snow-in-summer:

• Choose a sunny spot. Grow this plant type in sunny areas of your flower garden—snow-in-summer should receive at least eight hours of direct light per day. Partial shade combined with high humidity and poor soil will significantly increase the chances of root rot and other fungal diseases developing.
  
• Maintain seed spacing. Landscapers use snow-in-summer plants for ground cover because they grow to a maximum height of one foot before spreading horizontally. Since these summer plants are self-seeding, patches will grow thicker every year. To avoid overcrowding, sow your seeds roughly eight to twelve inches apart. Germination will begin in early spring, the year after you plant the seeds.
• Plant the seeds in a dry soil type. Some gardeners plant snow-in-summer along stone walls or rock gardens since these growing environments provide good drainage. You can also group these perennials with other summer flowers or garden plants that require full sun and well-draining soil.
• Plant the seeds in temperate climates. Endemic to the coastal regions of Europe and North America—areas that experience cool, dry summers—these plants are durable, deer-resistant, and drought-tolerant. Snow-in-summer thrives best in US Department of Agriculture (USDA) Hardiness Zones 3–7.
• Practice propagation control. These plants have an extremely rapid growth rate and a short bloom time. If you do not prune the spent blooms and flower stems, they will self-seed and grow thicker the next growing season. While this is desirable to some extent, overcrowding could lead to stunted new growth and a higher probability of plant disease and insect infestation. Take care to balance your pruning with the available space for expansion.

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