Not all Grevillea species are suited for container growth. Smaller or dwarf varieties, such as Grevillea rosmarinifolia or Grevillea lanigera, thrive in pots due to their compact size and adaptability. Larger species, like Grevillea robusta, may struggle with restricted root space. Select cultivars with slower growth rates and manageable heights (under 1.5 meters) to ensure long-term success in containers.
Grevilleas require well-draining pots to prevent root rot. Choose containers with ample drainage holes, preferably made of terracotta or breathable fabric to promote air circulation. A pot size of 30–50 cm in diameter is ideal for most dwarf varieties, allowing room for root expansion. Avoid overly large pots, as excess soil can retain moisture and harm the plant.
Grevilleas demand fast-draining, slightly acidic to neutral soil (pH 5.5–6.5). A mix of native Australian plant potting soil, coarse sand, and perlite (3:1:1 ratio) mimics their natural habitat. Avoid heavy clay or water-retentive mixes, as Grevilleas are highly susceptible to root diseases in soggy conditions. Adding a layer of mulch (e.g., gravel or pine bark) on top helps regulate moisture and temperature.
These sun-loving plants need at least 6 hours of direct sunlight daily. Place pots in a north or west-facing position (in the Southern Hemisphere) for optimal light exposure. In hotter climates, provide partial afternoon shade to prevent leaf scorch. Rotate the pot occasionally to ensure even growth, as Grevilleas may lean toward light sources.
Water deeply but infrequently, allowing the top 2–3 cm of soil to dry between waterings. Overwatering is a common killer—check drainage holes to ensure excess water escapes. Reduce frequency in winter or during rainy periods. Use rainwater or low-phosphorus tap water, as Grevilleas are sensitive to high phosphorus levels.
Feed sparingly with a low-phosphorus, slow-release fertilizer (e.g., native plant formula) in early spring and autumn. Over-fertilization can cause leaf burn or excessive leggy growth. Organic alternatives like composted tea tree mulch can provide gentle nutrients. Avoid high-nitrogen fertilizers, which may reduce flowering.
Regular light pruning after flowering encourages bushier growth and prevents legginess. Remove dead or crossing branches to improve air circulation. Pinch back tips of young plants to promote branching. Sterilize tools before use to prevent disease spread. Avoid heavy pruning, as Grevilleas may not regenerate from old wood.
Watch for aphids, scale, or spider mites, especially in dry conditions. Blast pests with water or use insecticidal soap. Root rot (from overwatering) and fungal leaf spots are common issues—ensure proper airflow and avoid wetting foliage. Isolate infected plants promptly to prevent spread.
Repot every 2–3 years or when roots circle the pot’s base. Gently loosen root balls and trim any dead roots before transferring to a slightly larger container with fresh soil. Spring is the best time for repotting to minimize stress. After repotting, water lightly and avoid fertilizing for 4–6 weeks.
In winter, protect pots from frost by moving them to sheltered areas or wrapping containers with hessian. Reduce watering in cooler months. During hot summers, increase monitoring for dehydration—leaf wilting or browning indicates stress. Adjust positioning seasonally to balance light and temperature needs.
