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Growing Your Own Growing Your Own Vegetables | Composting | Container Gardens | Fall/Winter Gardens | Fertilizing | Insect Pests | Plant Diseases | Planting Guidelines | Raised Beds | Regional Tips | Site Selection | Slugs | Soil Improvement | Tilling | Warm-season Crops | Watering | Weeds Fertilize Crops for High Yields Ensuring that your plants have the right amount of nutrients is critical to growing a successful garden. Plants require 16 elements. Of these, nitrogen (N), phosphorus (P), and potassium (K) are key nutrients that are contained in most commercial fertilizer mixes. In western Oregon, many soils don't contain enough boron, and several crops (e.g., cabbage, broccoli, cauliflower, raspberries, strawberries, beets, and carrots) also can benefit from an application of boron. Vegetable gardens are most productive with a soil pH of 6.0-7.0. Nutrients are most available for plant uptake at this pH. Many soils in eastern Oregon have a high pH (7.5-8.5) and benefit from an application of elemental sulfur to lower the pH. Enlarge photo Fertilizers containing potassium, phosphate, and organic nitrogen will be more available to plants if you work them into the top 2-3 inches of soil. Fertilizers often are classified as "organic" (e.g., manure, grass clippings, wood ashes, and blood meal) or "chemical." Bountiful gardens can be grown using either type, but there are some differences to consider. Plants can use chemical fertilizers as soon as they are applied, but organic fertilizers must be broken down by soil bacteria and fungi before the nutrients can be absorbed by plants. The compound the plant absorbs is the same regardless of the type of fertilizer. Before adding any fertilizer to your garden it is important to do a soil test. The soil test will tell you what nutrients are lacking, and then you can make an educated decision about which product to apply. Chemical and organic fertilizers are readily available as packaged mixes containing N, P, and K. When selecting a product, read the package label carefully; it will tell you how much of each nutrient the fertilizer contains. The nutrients always are listed in this order: nitrogen, phosphorus, potassium. Thus, a fertilizer labeled 5-10-5 contains 5 percent nitrogen, 10 percent phosphorus (in the form of phosphate), and 5 percent potassium (in the form of potash). In other words, every 10 pounds of this product contains 0.5 pound nitrogen, 1 pound phosphorus, and 0.5 pound potassium (10 lb product x 0.05 N = 0.5 lb N). It is important to note that N, P, and K behave differently in the soil. Take these differences into account when deciding how and when to apply fertilizer. Phosphate and potassium move slowly in the soil. To ensure that your plants receive adequate amounts of these nutrients, mix them into the soil. A common method is "banding." Dig a trench about 3 inches deep and 2 inches to the side of where the seeds or plants will be planted. Place fertilizer in the trench. As the plants' roots grow, they'll reach the fertilizer and quickly absorb the nutrients. Nitrogen in organic fertilizers must be released by soil organisms. Mix these fertilizers into the top 2 to 3 inches of soil so the organisms can go to work. Nitrogen in chemical fertilizers is available immediately and is highly water-soluble. It will be carried to the roots by irrigation and rain, so it doesn't need to be mixed into the soil. If it doesn't rain within a couple of days after you apply a chemical nitrogen fertilizer, water your garden to dissolve the nitrogen and move it into the root zone. Determining which nutrients are lacking in your garden, the type of fertilizer to use, and when and how much to apply varies among gardens. It even can vary from year to year in the same garden. Spending a little time determining how best to meet your plants' nutritional needs will result in a more bountiful harvest.

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