Gardeners who add sugar to their fertilizer are seeking improved vitality and overall plant growth. Unfortunately, this does not take place and, in fact, serious consequences can take place when gardeners apply sugar. Plants, which create their own sugar, will find that the additional resources disrupt their natural processes.
Food and Photosynthesis
Adding sugar to the soil can inhibit the plant's ability to produce its own food. Other biological processes become inhibited as energy is wasted in the additional processing of sugar.
Sugar added to fertilizer can influence the pH levels within the soil. Plants that are sensitive to a change in pH levels will be unable to absorb nutrients from the soil. The deficiency in nutrients will lead to stunted growth, inhibited reproduction and increased susceptibility to fungal disease. Sugar decomposing within the soil can also lead to increased bacterial rates which may later infect plants.
Instead of giving plants sugar, gardeners will experience increased growth by feeding plants a balance of macro-nutrients. This is best done by choosing the appropriate fertilizer for the growth of your specific plant. Healthy care of plants will help fight off pest and disease threats.
It is possible for sugar to stimulate the growth and production of microorganisms within the soil of the plant. Overstimulation of microorganisms at the roots can stress a plant and disrupt the absorption of nutrients.
Gardeners often claim the benefits of sugar added to soil. Although certain plants might have some positive reactions, there is no scientific research to back up these claims.