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- Palm Springs, CA
I have seen different kinds of plant food in the store. What’s the best way to use this? Do I need this for my flowers outside?
- Oakland, OR
The type of fertilizers available for indoor or outdoor use come in various forms. Soluble fertilizers provide an instant boost and are either sprayed on using a fertilizer applicator attached to your hose, or added to the watering can. Granular fertilizers provide a near instant, short term boost of necessary nutrients. Slow-release fertilizers are typically worked into the soil prior to planting, scattered on the soil, or applied as a side-dressing near plants during the growing season.
The nutrients are listed on the label and usually include nitrogen, phosphorus and potassium (N-P-K). The N-P-K ratio needed will depend on the plants being fertilized. In general, look for a high-nitrogen fertilizer for green (foliage plants, spinach and other greens, lawns, etc.); a higher-phosphorus ratio for fruit growth, including tomatoes, eggplants, peppers, etc.; and a higher potassium ratio for root growth. An N-P-K ratio of 12-12-12 or 15-12-12 is more suited for leafy vegetables; whereas 6-12-18 or 6-18-24 might be more suited to flowering and fruiting plants. In addition to NPK, organic fertilizers, aged manures and compost often contain added micronutrients such as boron, copper, iron, manganese and zinc. And yes, you do need to fertilize your outdoor flowers.