Anthuriums, with their vibrant, waxy blooms and striking foliage, add a tropical touch to any setting. While commonly grown indoors, these plants, native to the rainforests of Central and South America, can thrive outdoors in suitable climates, particularly USDA Zones 10-12. Growing anthuriums outside requires careful attention to their specific environmental needs to ensure their health and continuous display of color.
Choosing the Right Outdoor Spot
Selecting the right outdoor location is paramount for anthurium success, directly impacting their growth and flowering. Mimicking their natural rainforest habitat is key.
Light Requirements
Anthuriums flourish in bright, indirect light outdoors. They need about six hours of filtered sunlight daily to support healthy growth and abundant blooms. Direct, intense sunlight can quickly scorch their leaves, leading to browning and damage, so placing them under a tree canopy or on a covered patio is ideal. Insufficient light can result in stunted growth and a lack of flowers. If the plant appears leggy or struggles to bloom, it may need a brighter, yet still indirect, location.
Temperature and Humidity
These tropical plants prefer consistent temperatures, ideally ranging between 65°F and 85°F (18°C and 30°C). Temperatures below 60°F (15°C) can damage anthuriums, causing slowed growth, wilting, and potential leaf browning. High humidity, ideally between 60% and 80%, is equally important, reflecting their rainforest origins. In drier outdoor environments, grouping plants together or placing them near water features can help elevate ambient humidity.
Essential Outdoor Care Practices
Consistent outdoor care practices are crucial for maintaining vigorous anthuriums, supporting their health and promoting continuous flowering.
Soil and Potting
Anthuriums require a well-draining, airy potting mix that prevents waterlogging, which can lead to root rot. A suitable mix often includes components like pine or fir bark, perlite, and coco coir. These provide good aeration and drainage while retaining some moisture. If planting in containers, ensure they have adequate drainage holes. For in-ground planting, amending the soil with organic materials like peat moss or compost improves drainage and provides essential nutrients.
Watering Techniques
Outdoor anthuriums generally need more frequent watering than indoor plants due to increased exposure to sun and wind. Check the soil moisture before watering, allowing the top layer to dry slightly but never letting the soil become completely dry. Water thoroughly until excess water drains from the pot’s bottom, ensuring the entire root zone is hydrated. Adjust watering frequency based on weather conditions, such as increased watering during hot, dry spells and reduced watering during cooler or rainy periods.
Fertilization
During their active growing season, anthuriums benefit from regular fertilization. A balanced liquid fertilizer, such as a 20-20-20 NPK ratio, supports overall plant health and growth. For enhanced flowering, a fertilizer with a higher phosphorus content (e.g., 1:2:1 ratio) can be beneficial, applied at a reduced strength, typically quarter strength, every week or every other month. Avoid over-fertilization, as it can harm the plant; signs include yellow spotting on leaves.
Pruning
Pruning anthuriums outdoors helps maintain their shape, removes spent blooms, and improves air circulation within the plant. This can be done at any time of the year as needed. Use clean, sterile pruning shears to remove any discolored or dead leaves, cutting them at their base. Faded flowers should also be cut down to the base of their stems to encourage new blooms and redirect the plant’s energy. Removing suckers from the plant’s base can prevent them from drawing energy away from the main plant.
Protecting Your Anthurium Outdoors
Safeguarding anthuriums from outdoor threats and preparing for seasonal changes ensures their longevity and vibrancy.
Pest and Disease Management
Outdoor anthuriums can attract common pests like aphids, spider mites, mealybugs, thrips, and scale insects. Regularly inspecting plants helps in early detection. Environmentally friendly control methods include washing leaves with a strong stream of water to dislodge pests or applying insecticidal soap or neem oil. Good air circulation and proper watering practices help prevent fungal issues such as anthracnose, bacterial blight, and root rot, which thrive in wet, humid conditions. If root rot is suspected, remove the plant from its pot, trim affected roots, and repot in fresh, well-draining soil.
Cold Weather Protection and Bringing Indoors
Anthuriums are sensitive to cold and will be damaged by temperatures below 60°F (15°C), dying if temperatures drop to 40°F (4°C). In regions where temperatures fall below this threshold, grow anthuriums in containers so they can be moved indoors for colder months. Before bringing plants inside, thoroughly inspect them for pests and clean foliage to prevent indoor infestations. Gradually transition the plants from outdoor to indoor conditions to minimize shock, placing them in a warm, brightly lit indoor area, ideally with high humidity.