Blue Daze (Evolvulus glomeratus) is a low-growing perennial groundcover known for its vibrant, true-blue flowers. It adds consistent color to gardens and containers during warmer months. While it thrives in ample sunlight and heat, specific care strategies are needed for its survival through cooler periods.
Understanding Blue Daze’s Winter Needs
Blue Daze is a tropical perennial, highly sensitive to cold and susceptible to damage when temperatures drop below freezing. Its growth significantly slows in colder weather compared to its vigorous activity during warm seasons. In USDA Hardiness Zones 9 through 11, Blue Daze can survive outdoors year-round. Outside these zones, winter protection is necessary.
Outdoor Winter Protection
In mild winter climates, such as warmer parts of Zone 8 or sheltered areas of Zone 7, Blue Daze can be overwintered outdoors. Apply a 4 to 6-inch layer of organic mulch around the plant’s base, extending beyond its drip line, to insulate the root system from freezing temperatures.
During brief cold snaps or when temperatures dip below freezing, cover plants with a frost cloth or old blankets for warmth. Remove coverings once temperatures rise above freezing to allow air circulation and sunlight. Planting near a south-facing wall or under a protective overhang also provides natural shelter. These methods are most effective for short-duration cold events, not prolonged freezes.
Indoor Winter Care
In colder climates, bringing Blue Daze indoors for winter is the most reliable method for its survival. Indoors, the plant needs bright, indirect light. Supplemental grow lights can be beneficial if natural light is insufficient.
Reduce watering significantly during winter, allowing the top inch or two of soil to dry completely before rewatering. Overwatering is a common issue and can lead to root rot. Maintain a stable indoor temperature, ideally between 60°F and 70°F (15°C and 21°C), and avoid cold drafts. Address low indoor humidity by placing the plant on a pebble tray or by occasional misting.
Blue Daze does not require fertilization during this slowed growth period; resume feeding when active growth resumes in spring. Regularly inspect for common indoor pests like spider mites, mealybugs, or whiteflies, as early detection allows for prompt treatment and prevents widespread infestations.
Transitioning Back Outdoors in Spring
Once the danger of frost has passed and nighttime temperatures consistently remain above 50°F (10°C), Blue Daze can transition back outdoors. This process, known as hardening off, is important for plants overwintered indoors. Begin by placing the plant in a shaded, sheltered outdoor location for a few hours daily, gradually increasing its exposure to direct sunlight over 7 to 14 days.
This gradual acclimatization helps the plant adjust to harsher outdoor elements like stronger light, wind, and fluctuating temperatures, preventing shock and leaf scorch. After hardening off, move the Blue Daze to its permanent outdoor location for the growing season. Ensure proper watering and care as it resumes vigorous growth.