Fertilizers are used to aid and promote plant growth. They contain essential plant nutrients as well as fillers designed to make the nutrient distribution easier. There are different types of fertilizers and different fertilizer formulas. Some are made to encourage root establishment, while others are formulated to aid in fruit production. Fertilizers can be in liquid form or slow-release granules which dissolve when wet.
Scotts is the most popular brand of fertilizer used in the United States. This could be in part due to the company's "no-quibble" guarantee, which states that you can request a refund for any reason. Scotts is a large brand that offers a wide range of different types of fertilizers.
Nature's Touch & Dr. Earth
Nature's Touch is an organic-based fertilizer. Organic-based means that it has some chemical components and some organic ingredients, unlike most commercial fertilizers, which are completely chemically created. The selection of fertilizers offered is much smaller than some chemical brands, however. Dr. Earth is another brand that offers organic-based, blended fertilizers.
The Andersons brand creates fertilizers that are phosphorous-free, which is desirable in some regions of the United States that have soil already rich in phosphorous, such as planting areas near streams and lakes.
LESCO is marketed as a professional fertilizer and is endorsed by John Deere. This brand is used by many golf courses to maintain the turf. It can be difficult to find at local garden centers.
Green Guardian & Neptune's Harvest
Green Guardian offers fertilizers (most of them also kill weeds) that are 100 percent organic. In fact, the company states that some of their products are even edible, which might be attractive for gardeners who have animals. Neptune's Harvest is another brand that offers 100 percent organic fertilizers.