Gardening: New fertilizers offer science-based solutions

Nancy Szerlag
Special to The Detroit News
Nancy Szerlage at the OPC  garden

When choosing a fertilizer for my new garden, I look for a top-quality, organic-based slow-release products that would enrich and feed the soil as well as the plants. While chemical fertilizers promote plant growth, they do nothing to improve soil biology and can damage and deplete it over time.  

Whether choosing a product for indoor or outdoor plants, I always read the label to see what’s in the bag, bottle or box. I want to know just what is or isn’t in it and how much.  

Today’s hot button in organic fertilizers is plant bio-stimulants – diverse substances and microorganisms used to enhance plant growth and health. I have been using a bio stimulant-enhanced organic fertilizer in my display garden from the start, and the results have been amazing.  

One nutrient that’s a must is kelp, a processed seaweed that’s a renewable plant and soil amendment packed with 70 plus vitamins, amino acids and micro nutrients, which helps rebuild and restore depleted soil. Kelp also enhances plant growth and development. Micronutrients found in kelp boost a plant's natural immune system, helping the plant to resist attack from pests, disease and weather stresses, such as heat and drought.

Humic acid, while not a fertilizer, improves a plants' ability to take up nutrients, increases fertilizer retention, helps break up compacted soils and stimulates beneficial microbial activity. 

The beneficial fungi Mycorrhizae, in a variety of strains, both ecto and endo, is also on my list of must-haves. These beneficial organisms provide moisture and nutrients to plants from deep in the soil.   

Beneficial microbes, also called biological inoculums, perform a variety of tasks that enhance plant growth naturally. While it's not important to know or remember their names, here's a rundown on some of the tasks these good guys do. Beneficial microbes also break down nutrients found in the soil into a form plants can use. Trichoderma strains solubilize phosphorous tied up in the soil, making it unnecessary to fertilize with chemical phosphorous that leaches into the ground water and fouls our lakes and streams. Nitrogen fixers pull this most needed nutrient into the soil straight from the air. As these beneficial microbes colonize, live and die, their lifeless remains and excremental deposits also improve the structure of the soil. 

After reading the labels of dozens of products, Assure Transplant Success biologically enhanced fertilizer ( contains the most diverse blend of bio-stimulants and with the highest total counts I’ve found on the retail market. We volunteers use it in all our planting and call it our “magic fairy dust."   

Nancy Szerlag is a master gardener and Metro Detroit freelance writer. Her column appears Fridays in Homestyle. To ask her a question go to and click on Ask Nancy. You can also read her previous columns at