Fertilizer for Gardenias
- Gardenia's glossy leaves almost look fake they are so shiny and rigid. The leaves are oval and 2 to 4 inches long. The foliage is only part of the plant's appeal. Most gardenias are grown for the flowers with blooms ranging from single to double petaled. Flower color is primarily white but also comes in yellow and pale lavender. The blooms have a waxy appearance and are produced from March until June. The flower size varies by cultivar but may be up to 4 inches long.
- A soil test is useful to tell the gardener the pH and nutrient make up of his garden. Fertilizers provide supplemental nutrients for plants, but without a test, some can add too much of a nutrient that is already adequately supplied by soil. This can cause a toxicity, which can harm the gardenia. Once evaluating the soil, it is a good idea to start reading labels. You need to supply the macronutrients of nitrogen, phosphorus and potassium. If all of these or even one of the micronutrients is present in high quantities, you will need to choose a formula with a low ratio in that area. For instance, a fertilizer with ratio 12-6-6 is high in nitrogen and fairly low in phosphorus and potassium.
- Acid fertilizers are specially formulated to decrease the pH of soil. Much in the same way sulfur additions will increase acidity, acid fertilizers create a soil environment preferred by gardenias. You may fertilize gardenias two to three times in the growing season but don't fertilize in fall in colder climates. This may stimulate tender new growth that would be susceptible to cold temperatures. Fertilize with an acid fertilizer in March, September and sometime in summer in areas like Florida, Texas and Southern California. In northern zones, fertilize in March and June.
- Mulch gardenias in fall to protect them from cold temperatures, keep weeds at bay and add nutrients to the soil. Gardenias need plenty of water. Check the moisture level at 4 to 5 inches to determine if the plant needs water. Drip irrigation on gardenias will prevent water from remaining on leaves and causing fungal issues. Prune the plant just after blooming to shape it. You can also pinch new growth in June to encourage new branches. There are many pests of gardenias so a vigilant eye must be kept for signs of infestation. Apply appropriate controls as soon as you discover a problem.
