How to Feed an Evergreen Shrub

Select a high-nitrogen fertilizer. Every bag of fertilizer is labeled with three numbers, such as "10-5-5." The first number indicates the percentage of nitrogen, which, for evergreen shrubs, should be higher than the other two numbers.

Measure the number of feet the evergreen shrub covers, and calculate the square footage. A single small shrub that measures 3 feet wide and 3 feet deep is 9 square feet (3 times 3). An evergreen hedge 50 feet long and 4 feet deep is 200 square feet (50 times 4).

Calculate the amount of nitrogen in your fertilizer. Multiply the weight of the bag by the percentage of nitrogen in the fertilizer. For example, a 40-pound bag of fertilizer with a ratio of 10-5-5 has 4 pounds of nitrogen (40 times .10). If the ratio is 15-5-5, the bag contains 6 pounds of nitrogen (40 times .15).

Determine the amount of fertilizer to use by dividing the square feet of area to cover by 1000, and then multiply by the amount of actual nitrogen in your fertilizer. If the shrub covers 100 square feet, and your fertilizer contains 4 pounds of nitrogen, divide 100 by 1000 (0.1) and multiply by 4 (0.4). Measure out 0.4 pounds of fertilizer.

Spread the fertilizer around the shrub. Concentrate on the area beneath the farthest reach of its branches.

Work the fertilizer into the soil with a hoe if there is no grass around the shrub. Take care not to nick the roots. When there is grass, water the fertilized area slowly to allow the fertilizer to penetrate into the soil. Stop watering when the water begins to run off.