Any plant frequently referred to as "French perfume" must be a seriously fragrant one, and pink jasmine (Jasminum polyanthum) fills the late-winter and early-spring air with perfume to rival the most exclusive Parisian parfumeries. A perennial in U.S. Department of Agriculture plant hardiness zones 8 through 11, pink jasmine is a stellar example of the star-flowered, glossy-leaved genus Jasminum, and it responds well to the same fertilizer as its less potent -- but still fragrant -- relatives.
Why to Fertilize
The more flowers a jasmine produces, the more intense its fragrance will be. The best fertilizers for flower production contain more phosphorus than nitrogen or potassium. All three of those nutrients are considered essential for balanced plant growth. The three numbers separated by hyphens on any fertilizer's label indicate the product's percentages of, in order, nitrogen, phosphorus and potassium.
A 7-9-5 fertilizer works well for jasmine plants. It is 7 percent nitrogen, which ensures lush, healthy, green leaves, 9 percent phosphorus for abundant, large flowers and 5 percent potassium for strong roots and improved resistance to diseases, insects and drought.
When to Fertilize
Begin fertilizing a jasmine plant when its new growth appears in winter or spring; when the growth occurs depends on your USDA zone. Continue fertilizing until cooler temperatures and shorter daylight hours slow the plant's growth in fall. Weekly fertilizer applications are best to sustain healthy flower and leaf production.
How to Fertilize
One manufacturer recommends fertilizing an outdoor, in-ground jasmine with a solution made by mixing 1/2 teaspoon of its liquid, 7-9-5 fertilizer with 1 gallon of water. Pour the fertilizer-water mixture evenly around the base of the plant, and avoid wetting the plant's leaves. Wetting the leaves encourages fungal disease. Use the fertilizer-water solution once weekly in place of a regular watering session.
Dose an indoor, potted jasmine with a solution made by mixing 1/4 teaspoon of liquid, 7-9-5 fertilizer with 1 gallon of water. Apply the solution once weekly in place of a regular watering session.