Snow in Summer (Cerastium tomentosum) is a perennial groundcover known for its profuse white blooms, creating the illusion of fresh snowfall. Its distinctive silvery, woolly foliage adds ornamental value even when not in bloom. This spreading plant is a popular choice for various garden applications, including container gardening, where its cascading habit is appealing.
Setting Up Your Potted Snow in Summer
Pot Selection and Drainage
Choosing the right container is key for potted Snow in Summer. Terracotta pots are recommended for their porous nature, which allows for better air circulation and prevents overly wet soil. The pot size should accommodate the plant’s spreading habit; a larger bowl or a pot with a diameter of at least 8-10 inches is beneficial. Ample drainage holes at the bottom are essential, as poor drainage leads to root rot.
Soil Requirements
Snow in Summer thrives in well-draining, gritty soil, mimicking its native rocky alpine environments. Standard garden soil is too heavy and retains too much moisture for containerized plants. Create a suitable potting mix by combining equal parts of general-purpose potting soil with coarse sand or perlite to enhance drainage and aeration. This lean, well-draining medium prevents waterlogging, which harms the plant’s root system.
Light Needs
Optimal light conditions promote vigorous growth and abundant flowering. Snow in Summer performs best in full sun, requiring at least six to eight hours of direct sunlight daily. Full sun promotes the brightest silver foliage and maximizes bloom production. While it tolerates partial shade, this can result in less robust growth, fewer flowers, and an increased risk of fungal problems.
Daily Care for Potted Snow in Summer
Watering
Potted Snow in Summer needs consistent watering, as containerized plants dry out more quickly than those in the ground. While drought-tolerant once established, potted specimens require consistent moisture, especially during hot, dry periods. Allow the top inch or two of soil to dry out completely between waterings to prevent overwatering and root rot. Water deeply and slowly until water drains from the pot’s bottom.
Fertilizing
Snow in Summer prefers lean soil and does not require heavy fertilization. Over-fertilizing can lead to excessive foliage growth at the expense of flowers, or harm the plant. If the plant shows signs of underperformance, apply a very light, balanced, slow-release fertilizer or one high in phosphorus in early spring, just before blooming. For healthy plants in well-prepared soil, additional feeding is unnecessary.
Pruning and Deadheading
Regular pruning maintains the plant’s compact form, prevents legginess, and encourages more blooms. After the main flush of blooms in late spring to early summer, shear back spent flower stems. This practice tidies the plant, promotes new growth, and prevents self-seeding. Remove any dead or damaged stems to improve plant health and air circulation.
Winterizing Potted Snow in Summer
Preparing potted Snow in Summer for colder months ensures its survival. Although hardy in USDA Zones 3-8, containerized plants are more susceptible to freezing temperatures than those in the ground due to less root insulation. In regions with harsh winters, move pots to a sheltered location, such as an unheated garage, shed, or covered patio, for protection. For added insulation, wrap pots with burlap, bubble wrap, or place them inside larger containers filled with insulating material like straw or shredded leaves. During winter dormancy, the plant’s watering needs decrease; reduce watering to prevent root rot, ensuring the soil remains mostly dry. A period of cold dormancy benefits overall plant health.
Addressing Common Challenges
Common issues when growing Snow in Summer in pots often link to environmental conditions or care practices. Leggy growth, characterized by stretched stems and sparse foliage, indicates insufficient light. Move the pot to a full sun location to resolve this. Sparse blooming can also be a symptom of inadequate light or over-fertilization, which encourages leafy growth instead of flowers. Adjusting light levels and reducing fertilizer application can improve flowering. Yellowing leaves often signal overwatering or poor soil drainage, leading to root suffocation. Check soil moisture before watering and ensure the potting mix and container provide excellent drainage.