Reading Time: 4 minutes

Photos and article by Kristi Cook – You only need a basic understanding of how natural fertilizers work and you’ll be prepared to make the best decision for your garden’s needs. Gardens are hungry creatures, demanding endless applications of fertilizer to keep vegetables, fruits, and flowers growing throughout the season. Unfortunately, many find their plot’s needs increase each passing year despite frequent feedings. While chemical — or synthetic — fertilizers can certainly meet a garden’s immediate needs, natural fertilizers do the same while also building the soil’s fertility — thus reducing the need for supplements over time.

Why fertilize? Just like children, every plant needs specific nutrients to grow strong and healthy in order to lead a productive life. Iron, magnesium, calcium, zinc, and others are needed in low quantities and are often readily available in healthy soil. The most vital nutrients, nitrogen (N), phosphorus (P), and potassium (K), however, are the ones most quickly depleted and often require supplementation.

Fertilizing with synthetic products is much like feeding youngsters junk food — a fast release of nutrients creates a burst of energy followed by a rapid decline of vigor. The only way to quickly replace this lost energy is to reapply the “junk food.” And just like junk food, chemical fertilizers rapidly destroy the soil’s health. Mineral salts, which feed plants this quick burst of nutrients, in turn starve soil-building microbes, repel earthworms, reduce water retention, acidify soil, and eventually lead to “dead” soil. And because this soil is now dead, plants become dependent on higher and higher quantities of fertilizer.

Natural fertilizers, on the other hand, are the healthful fruits and veggies that every mother dreams of her children eating for dinner. These fertilizers are created from other plants, animals, or minerals (not manufactured mineral salts) and improve your soil. Because these fertilizers are natural, they slowly release nutrients as they are decomposed by soil- building microbes, earthworms, and other decomposers. Water- holding capacities increase, pH stabilizes, and the overall soil structure vital for plant growth improves with time.

Only use what you need. Just like synthetic fertilizers, it’s possible to overapply natural ones, too. Every two to three years, obtain a good-quality soil test via your local county extension office or other reputable source to determine your garden’s specific needs. After a few seasons of deep mulch gardening with adequate composting ingredients and natural fertilizer applications, you may be surprised to find your soil doesn’t need additional fertilizer.

Select a fertilizer. After determining your soil’s needs, you’ll need to select the proper nutrient source. Unlike chemical versions, many natural options supply primarily a single nutrient with little to no additional nutrients present. For example, blood meal provides only nitrogen while bone meal supplies primarily phosphorus with minimal nitrogen. So, if your soil test indicates a need for nitrogen but no phosphorus, you only have to spend a bit of money on the nutrient needed. For instance, if you only need nitrogen, add blood meal or fish emulsion. If tests show potassium is needed, choose a fertilizer high in potassium such as kelp or alfalfa meal.

However, if a soil test indicates you need a variety of nutrients, make your life simple by purchasing one of the premixed natural options now available. These premixed natural fertilizers offer many of the benefits of the all-in-one synthetic versions such as being balanced between all three main nutrients and are often formulated for specific crops such as tomatoes, roses, or acid-loving plants just as many of the synthetic fertilizers are. The biggest difference, however, is the natural fertilizers don’t degrade the soil, feed the plants naturally, and allow the soil to return to a more natural soil network.

As time goes on, big box stores are stocking these more frequently and in greater varieties which takes the guesswork out of natural fertilizers. These are an especially great alternative if you don’t wish to perform soil tests or don’t want to measure lots of different fertilizers. They are, however, pricier than individual sources and run the risk of supplying nutrients your garden may not need.

Converting your garden space over to more natural fertilizers is a simple task of getting a quality soil test, selecting a fertilizer based on those results, and monitoring your soil’s levels every few years as the soil returns to a more fertile, natural state. And much like the conventional fertilizers with their premixed/balanced ratios of each nutrient, today’s natural fertilizers are also available in premixed form with known NPK ratios capable of feeding any variety of crops you may have growing in your garden.

Do you have nutrient rich soil? Do you use natural fertilizers? We would love to hear from you!

Originally published in Countryside July/August 2020 and regularly vetted for accuracy.