Kalanchoe plants are popular houseplants, appreciated for their vibrant, long-lasting blooms and succulent foliage. While generally low-maintenance, providing the right nutrients through fertilizer is important for their sustained health, vigorous growth, and abundant flowering. Proper fertilization helps these resilient plants thrive.
Understanding Kalanchoe Fertilizer Needs
Kalanchoe plants benefit from a balanced supply of essential nutrients to support their growth and flowering. They primarily need nitrogen (N), phosphorus (P), and potassium (K), often referred to as NPK. Nitrogen promotes lush, green foliage, contributing to the overall vigor of the plant. Phosphorus is crucial for strong root development and encourages the formation of abundant flowers. Potassium supports overall plant health, aiding in water regulation and enhancing the plant’s resistance to environmental stress and disease.
While a balanced NPK ratio like 10-10-10 or 20-20-20 can be suitable, some sources suggest a formula slightly higher in phosphorus to encourage blooming, or even a low-nitrogen, moderate-phosphorus, and high-potassium blend, such as 2-7-7, which supports compact growth and robust flowering. Liquid, water-soluble fertilizers are often favored for their quick absorption, providing an immediate nutrient boost. Slow-release granular fertilizers can also be used, releasing nutrients gradually over time.
Fertilizing Kalanchoe
The active growing season for Kalanchoe typically spans from spring to early fall, which is the ideal time for fertilization. During this period, a general recommendation is to fertilize every two to four weeks. As autumn approaches, and the plant prepares for dormancy, reducing fertilization to once every six to eight weeks is advisable. During winter, when growth slows, pause fertilization or apply very sparingly with a diluted solution if the plant is still receiving light indoors.
When using liquid fertilizers, it is important to dilute them to half the recommended strength to prevent chemical burn. Apply the diluted fertilizer directly to the soil, ensuring the soil is already moist to avoid root burn. Avoid getting the fertilizer solution on the leaves. For granular fertilizers, apply them at the base of the plant and then water thoroughly to help the nutrients penetrate the soil.
Common Fertilizer Issues and Solutions
Incorrect fertilization can cause issues in Kalanchoe plants. Over-fertilization can cause symptoms such as burnt leaf tips, yellowing and wilting of lower leaves, stunted growth, or a visible crust of fertilizer salts on the soil surface. In severe cases, roots may become black and limp due to chemical burn. To address over-fertilization, gently remove any visible crust from the soil surface and then leach the soil by thoroughly flushing it with plain, room-temperature water multiple times, allowing excess water to drain completely.
Conversely, under-fertilization can also hinder a Kalanchoe’s health. Signs of nutrient deficiency include pale or yellowing leaves, a general lack of new growth, or sparse and absent blooms. The solution for under-fertilization involves adjusting the fertilization schedule and concentration, ensuring the plant receives a balanced fertilizer at the appropriate frequency during its growing season.