Pothos ( Epipremnum aureum), also known as Devil’s Ivy, is a popular houseplant cherished for its resilient nature and cascading vines. While primarily recognized as an indoor specimen, pothos can flourish outdoors if specific environmental conditions are met. This allows gardeners in suitable climates to extend its lush foliage beyond their homes.
Suitability for Outdoor Growth
Pothos originates from tropical islands, influencing its outdoor cultivation needs. For year-round outdoor viability, it thrives in USDA Plant Hardiness Zones 10 to 12, where temperatures consistently remain above freezing. Gardeners in Zone 9 might find success, though plants in this zone face risks during occasional cold snaps.
Optimal growth occurs when temperatures are between 70 to 90 degrees Fahrenheit (21-32°C), ideally not dropping below 50 degrees Fahrenheit (10°C) at night. Temperatures below 40 degrees Fahrenheit (4°C) are detrimental, and freezing temperatures are fatal. Higher humidity levels are beneficial for vigorous growth.
Light exposure is another factor. Outdoors, pothos prefers bright, indirect light or partial shade, mimicking its natural understory. Direct, harsh sunlight can scorch its leaves. Too little light can lead to stunted growth and a loss of variegation. Gradual acclimatization is recommended when moving a houseplant outdoors to prevent shock.
Cultivating Outdoor Pothos
Both in-ground and container planting options are viable, depending on your climate. Containers offer flexibility for those in borderline zones, allowing plants to be moved indoors when temperatures drop.
Pothos requires well-draining soil to prevent root rot. For container-grown plants, use a high-quality potting mix with ingredients like coco coir, orchid bark, perlite, and sphagnum peat moss. When planting in the ground, amend heavy garden soil with organic matter such as compost or peat moss to improve drainage and nutrient content. A slightly acidic soil pH, between 6.0 and 7.0, is preferred for optimal nutrient absorption.
Watering practices for outdoor pothos differ from indoor routines due to increased evaporation. Allow the soil to dry out partially between waterings, typically when the top one to two inches feel dry to the touch. More frequent watering may be necessary during warmer, drier periods, sometimes daily in summer. Reduce watering frequency during cooler months or periods of dormancy.
During the active growing season (spring through summer), apply a balanced liquid fertilizer with an NPK ratio like 10-10-10 or 20-20-20. This can be applied monthly, often diluted to half strength to prevent over-fertilization. Slow-release fertilizer pellets can also be used.
Protecting and Managing Outdoor Pothos
Cold protection is important where temperatures might occasionally dip below ideal ranges. For container-grown plants, bring them indoors when overnight temperatures consistently fall below 50 degrees Fahrenheit (10°C). In-ground plants in marginal zones can be covered with frost cloths or temporary shelters during cold snaps.
Pest management is an ongoing concern for outdoor plants, as they are more susceptible to infestations. Common pests include aphids, mealybugs, and spider mites, which feed on plant sap. Regular inspection of leaf undersides helps detect infestations early. Organic control methods, such as insecticidal soap or neem oil, can manage these pests. A strong stream of water can also dislodge aphids and spider mites.
Preventing disease involves maintaining appropriate cultural conditions. Root rot, indicated by yellowing leaves and stunted growth, is caused by overwatering or poorly draining soil. Ensuring the soil dries between waterings and providing good air circulation helps mitigate this risk. Fungal leaf spots can also occur; remove affected leaves and improve air circulation to prevent their spread.
Managing vigorous growth is important, especially given pothos’ climbing nature. Pruning controls the plant’s size and shape while promoting bushier growth. Regular trimming prevents leggy vines and encourages new foliage. Pothos naturally climbs using aerial roots; providing supports like trellises or allowing it to climb walls or trees can guide its growth and create striking vertical displays.
Safety and Environmental Considerations
Pothos contains calcium oxalate crystals, making it toxic if ingested by pets or humans. These crystals can cause irritation, burning, and swelling of the mouth, lips, and throat, along with digestive upset. While ingestion is not fatal, it can lead to significant discomfort, including excessive drooling, vomiting, and difficulty breathing. Place outdoor pothos in areas inaccessible to children and pets.
The plant’s robust growth and adaptability contribute to its potential to become an invasive species in tropical and subtropical regions. In warm, frost-free climates, particularly in USDA Zones 10-12, pothos can escape cultivation and outcompete native vegetation. Its ability to climb and blanket structures, including trees, can block sunlight and disrupt local ecosystems. Responsible cultivation, such as keeping it in containers, is important to prevent its spread and protect local biodiversity.