Organic and non-organic fertilizers can affect plant growth in different ways. According to GardenGudies.com, inorganic fertilizer can be responsible for over-fertilization, a process that overwhelms a plant by receiving too many nutrients at once, affecting overall plant growth. Organic fertilizers, on the other hand, contain more natural properties that slowly acclimate plants into growing naturally.
GardenGuides.com also notes that over-fertilization can lead to higher salt concentration, which can harm a plant's growth ability affect the quality of the roots. In non-organic fertilizers, companies often use only the most essential elements when it comes to plant nutrition: nitrogen, phosphorous and potassium. Other elements can include seaweed, peat or guano.
According to Gardening Tips and Ideas, inorganic fertilizers are generally chemical and mineral based, while the organic variety generally comprises decomposed matter from plants and animals. The consensus among gardeners is that organic-based fertilizer is more helpful to plants because it contains natural elements that microbes need to break down and release nutrients into plants.
Gardening Tips and Ideas also mentions the different categories of fertilizers to consider, such as the slow-release variety, a type of fertilizer that slowly releases nitrogen in minimal doses without having to fertilize in small intervals. Other fertilizers contain herbicides and insecticides, in order to prevent weed and pest infestations.