Best Fertiliser for Rubber Plants: How to Feed, Grow & Maintain Ficus elastica Indoors

Rubber plants (Ficus elastica) are one of the most popular indoor houseplants in Australia, prized for their glossy, oversized leaves and architectural growth habit. While they are relatively low maintenance, a well-fed rubber plant will reward you with faster growth, richer colour, and fuller foliage—especially when grown in pots indoors.

Rubber Plant Overview – Growth Habit & Characteristics

Native to Southeast Asia, Ficus elastica belongs to the fig family and has been a household staple for generations. It grows upright, with thick, oval-shaped leaves that can range in colour from deep green to burgundy or variegated cream and green. Key facts:

Botanical name: Ficus elastica
Common names: Rubber plant, rubber tree, rubber fig
Height: Can reach 1–3 m indoors; much taller in tropical gardens
Growth: Upright, woody stem with aerial roots; slow to moderate grower

Rubber plants are well suited to bright indoor spaces and add a lush, sculptural quality to living rooms, offices, and balconies. With consistent care and the right fertiliser, they develop thick, healthy leaves and sturdy stems.

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How to Grow & Maintain Rubber Plants Indoors

Ficus elastica grows best in bright, indirect light and prefers warm, stable indoor conditions. It is relatively tolerant of dry air but can slow down in cooler or low-light environments. With proper soil, watering, and occasional pruning, it can thrive for years in the same container.

Light: Bright, filtered light is ideal. Avoid harsh afternoon sun which can scorch leaves.
Soil: Use a well-draining indoor potting mix enriched with perlite or coco coir.
Watering: Let the top 4–5 cm of soil dry out between watering. Water less often in winter.
Temperature: Best range is 18–26 °C. Keep away from air conditioners or cold drafts.
Pruning: Can be pruned to control height and encourage branching. Always cut above a node.

Rubber plants enjoy being slightly root-bound, so only repot when roots circle the base. Clean leaves monthly to remove dust and enhance photosynthesis.

The Best Fertiliser for Rubber Plants

Rubber plants are heavy foliage producers and benefit from regular feeding during the growing season. The goal is to provide a balanced, complete nutrient profile to support lush, glossy leaves without overstimulating vertical growth.

What Nutrients Do Rubber Plants Need?

Nitrogen (N): Essential for strong leaf and stem development
Phosphorus (P): Supports root health, especially in containers
Potassium (K): Helps regulate water use and cell development
Micronutrients: Iron, magnesium, manganese to prevent yellowing and weak new growth

Fertilising Schedule

Spring to early autumn: Feed every 3–4 weeks with a diluted liquid fertiliser
Late autumn to winter: Stop feeding during dormancy unless actively growing under lights

Recommended product: Use CompleteGrow’s Indoor Plant Food Concentrate, which provides a safe and balanced liquid feed ideal for large-leaf indoor plants. It’s low-odor, easy to mix, and formulated for consistent foliage colour and gentle feeding that won’t burn roots.