Epiphyllum, often called orchid cacti, are unique epiphytic cacti cherished for their striking, often fragrant, blooms. Native to Central and South American rainforests, these epiphytic cacti grow on other plants, absorbing moisture and nutrients from their environment. Proper fertilization supports their health and encourages abundant flowering, mimicking their natural nutrient uptake.
Selecting the Ideal Fertilizer
Epiphyllums thrive with a specific nutrient balance, differing from typical desert cacti. They generally prefer fertilizers with lower nitrogen (N) and higher phosphorus (P) and potassium (K) to promote flowering over excessive foliage growth. A common recommendation is a 2-10-10 or 0-10-10 NPK ratio, especially for encouraging blooms. After the blooming season, a more balanced formulation like 10-10-10 or 5-5-5 can be used to support overall plant health.
Both synthetic and organic fertilizers are effective, each with distinct characteristics. Synthetic fertilizers offer readily available nutrients for a quick boost, but risk salt buildup and over-fertilization. Organic options, like fish emulsion or seaweed extract, release nutrients slowly as microorganisms break them down, improving soil health and reducing burn risk. While safer against over-feeding, organic nutrient levels can be less precise.
Micronutrients are important for Epiphyllum health, even in small quantities. These include elements like iron, boron, manganese, zinc, copper, and molybdenum, which contribute to various plant functions. While specific micronutrient requirements for Epiphyllums are not always detailed, a complete fertilizer formulated for flowering plants or orchids often includes these trace elements.
Establishing a Fertilization Routine
A consistent fertilization routine is important for Epiphyllums, tailored to their growth and dormancy cycles. During their active growing season, typically from early spring through fall, Epiphyllums benefit from regular feeding. Some growers feed every two weeks during this period, while others opt for monthly applications.
Dilution is important to prevent root burn, as Epiphyllums naturally grow in low-nutrient environments. Use fertilizer at half or one-third of the strength suggested on the product label. For instance, if using a 20-20-20 fertilizer, dilute it to half strength and apply weekly when conditions allow.
Apply diluted fertilizer by watering it into the soil to ensure nutrients reach the roots efficiently. Water the plant thoroughly with plain water before fertilizing, especially with liquid formulations, to prevent root shock and improve absorption. During winter dormancy, suspend or significantly reduce fertilization to allow the plant to rest and prepare for the next blooming cycle.
Addressing Fertilization Problems
Incorrect fertilization can lead to visible issues in Epiphyllums. Over-fertilization, or “fertilizer burn,” occurs when excessive salts accumulate, drawing water from roots. Symptoms include yellowing and wilting of lower leaves, browning of leaf margins and tips, stunted growth, and sometimes a white crust on the soil surface. If these signs appear, stop fertilizing immediately and thoroughly flush the soil with plain water to leach out excess salts.
Conversely, under-fertilization can result in poor growth and a lack of blooms. Signs of nutrient deficiency include yellowing leaves, slow growth, or a general decline in vigor. For example, overall pale yellowing of older leaves can indicate a nitrogen deficiency, while stunted growth with purple discoloration might suggest a lack of phosphorus. If observed, review the fertilization routine and gradually increase appropriate nutrient application.
Environmental factors can mimic nutrient problems; consider the plant’s overall care. For instance, shriveled or limp stems often indicate underwatering, not necessarily a nutrient issue. Similarly, yellowing leaves can also result from overwatering. Adjusting watering practices, ensuring proper drainage, and providing adequate light are all part of maintaining a healthy Epiphyllum and preventing fertilization-related problems.