The Royal Red Plant, a cultivar of Philodendron erubescens, is a highly sought-after tropical houseplant prized for its striking, deep burgundy-red foliage. Unlike many green philodendrons, the ‘Royal Red’ maintains a vibrant color on both new and mature leaves, making it a dramatic addition to any indoor collection. This guide provides instructions for cultivating this attractive plant successfully, covering its preferred environment and routine maintenance needs.
Ideal Growing Environment
The rich, saturated color of the Royal Red Philodendron depends heavily on receiving sufficient bright, indirect light throughout the day. Placing the plant near an east or west-facing window often provides the optimal balance without exposing the leaves to harsh, direct midday sun. Intense, unfiltered sunlight can cause the red pigments to fade or lead to scorch marks on the leaf surfaces. Insufficient light, conversely, will cause the deep red coloration to revert to a duller green.
This plant thrives in stable temperatures, ideally maintained between 65°F and 80°F (18°C–27°C). Temperatures below 55°F (13°C) for extended periods can cause chilling damage and inhibit growth, so keep it away from cold drafts. High atmospheric moisture is beneficial, with 60% relative humidity being the preferred range. Increase localized humidity by placing the potted plant on a shallow pebble tray filled with water or by grouping it closely with other moisture-loving plants.
Potting and Soil Requirements
The physical substrate for a Royal Red must be highly porous and well-draining to prevent waterlogging, which is a common cause of root disease. A suitable aroid mix should contain components that promote aeration, such as orchid bark, coarse perlite, and a small amount of coco coir or peat moss. This chunky composition allows oxygen to reach the roots while still retaining a suitable level of moisture. Heavy, dense standard potting soil should be amended or avoided entirely.
Repotting should occur when the plant exhibits signs of being root-bound, such as roots circling the drainage holes or growth slowing. Select a pot only one to two inches larger in diameter than the previous one to avoid excessive soil volume. Providing a vertical structure like a moss pole encourages larger leaf growth and better overall form, as the Royal Red naturally climbs. The aerial roots will attach to the moist support, aiding in stability and nutrient uptake.
Essential Watering and Feeding Schedule
Effective watering involves thoroughly saturating the potting medium until water flows freely from the drainage holes. Before watering again, allow the top inch or two of the soil to completely dry out, which prevents the roots from sitting in stagnant moisture and risking fungal issues. Frequency varies based on environmental conditions, but typically requires watering once every seven to ten days during the active growing season.
The plant’s metabolic activity slows during the cooler winter months, necessitating a reduction in watering frequency. During this dormant period, allow the soil to dry out closer to halfway down the pot depth before rewetting.
To support robust foliage growth, the Royal Red benefits from regular feeding with a balanced, liquid houseplant fertilizer. Look for a formula where the NPK ratio is relatively even, such as a 10-10-10 or similar general-purpose nutrient blend.
Fertilization should be applied only during the spring and summer peak growing period. Dilute the liquid fertilizer to half the strength recommended on the product label to prevent nutrient burn and salt accumulation. Application should occur monthly, coinciding with a watering session to distribute the nutrients evenly. Cease all feeding completely during the autumn and winter.
Addressing Common Issues and Pruning
Leaf discoloration often signals a maintenance imbalance; yellowing leaves typically indicate overwatering, while crispy brown tips are a sign of low humidity. Regular inspection of leaf undersides helps identify pests like mealybugs, which resemble cottony masses, and spider mites, which leave fine webbing. Treating minor infestations promptly with a horticultural oil, such as neem oil, or a gentle insecticidal soap is the most effective measure.
Pruning is valuable for maintaining the plant’s shape and encouraging denser, bushier growth habits. Use clean shears to remove leggy vines or damaged foliage, making the cut just above a leaf node on the stem. Healthy stem cuttings can be used for propagation, allowing the grower to easily start new Royal Red plants.