Ixora is a popular tropical flowering shrub, cherished for its vibrant clusters of red, pink, orange, or yellow blooms. This plant is a heavy feeder, requiring a consistent and rich supply of nutrients to maintain its glossy green foliage and continuous flowering. Ixora is high-maintenance regarding its feeding schedule and soil requirements, particularly its preference for acidic conditions, which impacts its ability to absorb necessary nutrients. A precise and regular fertilization regimen is necessary for the plant to thrive.
Recommended NPK Ratios and Fertilizer Types
Ixora nutrition relies on the proper balance of Nitrogen (N), Phosphorus (P), and Potassium (K), represented by the NPK ratio. Ixora requires a fertilizer relatively high in Phosphorus (the middle number), which promotes flower bud development. A ratio such as 8-10-10 or a slightly more bloom-focused formula encourages heavy flowering without causing excessive foliage growth. Balanced NPK formulas like 20-20-20 or 10-10-10 are also effective when applied regularly during the growing season, as consistent feeding is more important than a single heavy application.
Gardeners can choose between slow-release granular products and water-soluble liquid feeds. Slow-release granular fertilizers feed the plant gradually over several months, reducing the risk of nutrient burn and providing a steady supply, making them preferred for established landscape shrubs. Water-soluble liquid fertilizers provide an immediate and easily absorbed nutrient boost, ideal for container-grown Ixora or quickly addressing deficiencies. Since liquid feeds are absorbed quickly, they allow for more frequent application, typically every two to four weeks during active growth.
Essential Micronutrients and Deficiency Correction
Ixora requires highly acidic soil, ideally with a pH range between 5.0 and 5.5. In alkaline soil (high pH), essential micronutrients become chemically locked up and unavailable to the roots, even if present in the soil. Iron (Fe) and Manganese (Mn) are the two most frequently affected micronutrients.
The most visible sign of deficiency is chlorosis, where new leaves turn yellow while the veins remain green, a classic symptom of iron deficiency. A lack of Phosphorus (P) and Potassium (K) can cause reddish-purple spots on older leaves. Standard NPK fertilizers cannot solve this problem because the issue is nutrient availability rather than presence.
To correct these deficiencies, the soil pH must be lowered, or nutrients must be applied in an immediately absorbable form. Using fertilizers formulated for acid-loving plants helps maintain the necessary low pH. For a quick remedy, especially for iron deficiency, applying chelated iron is recommended. Chelated forms of iron and manganese remain soluble and available to the plant even in higher pH soil, offering a fast-acting solution to reverse chlorosis.
Optimal Timing and Application Techniques
The Ixora should be fed regularly throughout its active growing season, generally from early spring through late autumn. In-ground plants typically require a monthly application of fertilizer. Potted Ixora may need feeding every two to four weeks because nutrients leach out more quickly from containers. As temperatures drop in late fall and winter, the feeding schedule should be reduced or halted entirely to allow the plant to enter a resting phase.
Proper application technique is important to prevent fertilizer burn. Always saturate the soil with water before applying any fertilizer, especially concentrated liquid feeds or granular products, to hydrate the roots and dilute the salts. Granular products should be spread evenly around the plant’s drip line (the outer edge of the foliage) and kept a few inches away from the central stem. After application, lightly water the area again to move the nutrients into the root zone.