Lemongrass (Cymbopogon citratus) is a popular herb valued for its culinary and medicinal uses. While generally considered low-maintenance, providing proper nutrition through fertilization is important for encouraging vigorous growth and a plentiful harvest. This helps ensure the plant develops strong stalks and lush foliage.
Why Fertilization Matters for Lemongrass
Lemongrass, like all plants, requires specific nutrients to thrive. Fertilization supports robust stalk development and abundant, healthy leaves. Adequate nutrition also enhances the plant’s overall health and improves its resilience against common pests and diseases.
Container-grown plants often deplete soil nutrients more quickly than those in garden beds. This makes regular feeding important for potted lemongrass, as it relies on external nutrient sources. Supplying the right balance of nutrients ensures the plant maintains vigorous growth and a generous yield.
Choosing the Best Fertilizer for Lemongrass
Lemongrass primarily benefits from nitrogen, essential for developing leafy growth and strong stems. A balanced fertilizer or one with a higher nitrogen content is suitable. NPK ratios around 10-6-4 or 6-4-4 are often suggested, supporting overall growth, roots, and leaves.
Both organic and synthetic fertilizers can effectively nourish lemongrass, with the choice depending on personal gardening preferences. Organic options, such as compost, well-rotted manure, fish emulsion, or blood meal, release nutrients slowly and improve soil structure. Compost tea and well-rotted manure provide a gradual supply of essential macronutrients and beneficial microbes. Blood meal is a good nitrogen booster for strong leaf and stem development. Synthetic granular or liquid fertilizers offer precise nutrient ratios and a quicker nutrient boost.
When and How to Fertilize Lemongrass
Fertilize lemongrass during its active growing season, typically from spring through summer. For in-ground plants, a monthly application can be beneficial. Potted lemongrass often requires more frequent feeding, such as weekly or every 10 days, using a half-strength solution of a balanced soluble fertilizer. Consistent feeding during these warmer months supports continuous growth.
For granular fertilizers, sprinkle the recommended amount around the base of the plant, avoiding direct contact with stalks to prevent burn. Water thoroughly after applying granular fertilizer to dissolve nutrients and carry them into the soil, preventing root burn. When using liquid fertilizers, dilute them to half-strength before application to avoid over-fertilization. This diluted solution can be applied as a soil drench. Organic amendments like compost or well-rotted manure can be incorporated into the soil around the plant, slowly releasing nutrients as they decompose.
Recognizing and Addressing Nutrient Issues
Yellowing leaves, especially older ones, often indicate a nitrogen deficiency, which can also lead to stunted growth. A lack of phosphorus might manifest as purple-tinged leaves and weak stems, while brown leaf edges could signal a potassium shortage. Addressing these issues involves applying a fertilizer rich in the missing nutrient.
Over-fertilization can also harm lemongrass, often appearing as “fertilizer burn.” Signs include brown or crispy leaf tips and margins, wilting, slow growth, or a crust of fertilizer on the soil surface. Excess fertilizer can draw moisture away from the roots, leading to dehydration and root damage. If over-fertilization occurs, immediately flush the soil with plenty of water to leach out excess nutrients. After flushing, wait a few weeks before resuming fertilization to allow the plant to recover.