Bougainvillea, with its vibrant, papery bracts, brings tropical color. While commonly seen thriving outdoors, cultivating this striking plant indoors is gaining interest. Successfully growing bougainvillea can be a rewarding endeavor, transforming indoor spaces.
Essential Indoor Care
Providing proper environmental conditions is essential for indoor bougainvillea. This plant requires substantial direct sunlight to flourish and produce colorful bracts. Place it within two meters of a south-facing window or in a conservatory, ensuring at least six hours of direct sun daily. Insufficient light leads to spindly growth and reduced flowering, as the plant prioritizes vegetative growth over bloom production.
Watering practices for bougainvillea differ, as they prefer slightly drier conditions. Allow the top half of the soil to dry out between waterings. Overwatering quickly leads to root rot, yellowing leaves, and bud or flower loss. Persistent droughts cause rapid flower or foliage drop. During active growth, keep the soil relatively moist, but in colder months, reduce watering significantly.
The appropriate soil mix for bougainvillea is well-draining and slightly acidic (pH 5.5-6.0). A suitable potting mix ensures good drainage. Bougainvillea performs well when its roots are somewhat restricted, preferring to be slightly pot-bound. When repotting, choose a container only one size larger.
Bougainvillea prefers warm temperatures, 60-70°F (15-21°C) for active growth and blooming. It tolerates temperatures down to 30°F (-1°C) for short periods, but sustained temperatures below 40°F (4°C) cause leaf yellowing and drop. While bougainvillea tolerates lower humidity, occasional misting or placing a humidity tray nearby helps in dry indoor environments.
Regular fertilization supports robust growth and abundant blooms during the growing season. During flowering, feed fortnightly with a potassium-based fertilizer. After flowering, apply a general “Houseplant” fertilizer monthly. Avoid over-fertilizing, which can cause root burn, and cease feeding during dormancy.
Encouraging Abundant Blooms
Achieving prolific blooms on indoor bougainvillea requires specific strategies. High light intensity is paramount; insufficient sunlight results in vegetative growth, producing leaves rather than colorful bracts. A south-facing window with at least 6-8 hours of direct, intense sunlight daily encourages vibrant bracts.
Fertilizer choice plays a role in bloom encouragement. A higher phosphorus content is beneficial for flower production. During the blooming cycle, apply a high-phosphorus, bloom-boosting fertilizer every 2-3 weeks to enhance flowering. Excessive nitrogen leads to leafy growth at the expense of blooms.
Strategic water stress can encourage bract production. Bougainvillea, being drought-tolerant, responds to periods of slight dryness by initiating blooms. Allowing the soil to dry out considerably between waterings, to the point where leaves might slightly wilt, can trigger a blooming cycle. After this controlled dry period, a thorough watering prompts new growth and subsequent flowering.
Pruning and Training for Indoors
Pruning is important for managing indoor bougainvillea, helping maintain a suitable size and shape. Regular maintenance pruning involves deadheading spent bracts and removing yellowed or dying leaves.
Shaping pruning, often done after a flowering flush, controls the plant’s form and density. Since bougainvillea blooms on new wood, trimming promotes fresh growth and more blooms. Hard pruning, cutting branches back by about a third, can be done in late winter or early spring before new growth begins to stimulate a vigorous flush of blooms.
Training techniques can transform bougainvillea into various forms for indoor display. These versatile plants can be trained to climb trellises or shaped into a small shrub or tree. Winding wayward stems back into the plant helps maintain a compact appearance and prevents sprawling.
Troubleshooting Common Issues
Indoor bougainvillea can experience several common problems. Leaf drop is a frequent concern, often caused by changes in climate, such as sudden temperature fluctuations or reduced light. Overwatering or underwatering can also lead to leaf loss.
Yellowing leaves signal an imbalance in care. Overwatering leads to root rot and yellowing; underwatering causes dehydration and yellowing. Nutrient deficiencies, such as a lack of nitrogen, magnesium, or iron, can also cause yellow foliage.
Lack of blooms often points to insufficient light or nutrient imbalance. Bougainvillea requires abundant direct sunlight to produce colorful bracts; without it, the plant primarily grows foliage. Over-fertilizing with high-nitrogen products can suppress flowering, as energy is directed towards leafy growth instead of blooms.
Pests like spider mites, mealybugs, and aphids can infest indoor bougainvillea. Inspect the plant regularly, especially the undersides of leaves, to detect infestations early. Treat affected plants with insecticidal soap or neem oil.
Winter Care and Dormancy
In temperate climates, bougainvillea typically enters dormancy during cooler, darker winter months. This natural adaptation conserves energy due to reduced light and lower temperatures. During this time, the plant commonly sheds many or all of its leaves.
To prepare the plant for winter, move it to a cool, frost-free location, such as a basement or garage (40-50°F / 4-10°C). During dormancy, drastically reduce watering to once or twice a month. Suspend fertilizing entirely, as the plant is not actively growing.
Alternatively, if a bright, sunny spot like a south-facing window is available, bougainvillea can be kept actively growing indoors throughout winter. The plant may still experience some leaf drop due to lower light intensity. Watering should be reduced compared to summer, but not as severely as if forced into full dormancy.
As spring approaches, gradually re-acclimate the plant to brighter conditions. Increased watering and a balanced fertilization schedule encourage new growth. Once frost danger passes, move the bougainvillea outdoors to benefit from intense sun, leading to vibrant blooms.