Organic or Synthetic Fertilizer: What’s Best for Your Garden (and the Planet)?

Plants, like all living organisms, require nutrients to live. No matter how perfectly fertile your garden soil may be, over time it will lose nutrients that must be replenished. A successful harvest will always require some degree of fertilization. 

This spring, give organic fertilizer a try. Your soil will thank you.  

Organic fertilizer comes from living matter, including plants, animals and manure. Synthetic or chemical fertilizer is derived from chemicals and minerals from the earth. Though there are pros and cons to using both, a living soil fertilized with organic fertilizer is better for the planet and will yield healthier food.   

Both types of fertilizer provide plants with nitrogen, phosphorus and potassium, the three essential nutrients they need to grow. Plants respond more quickly to chemical fertilizer. Even in poor soil conditions, they can still do well. 

Organic fertilizer will make your soil healthier in the long run, but it will take up to a few years to see all of the benefits. Organic fertilizers encompass a broad range of organic materials including fish emulsion, kelp, bone and blood meal, worm castings, coffee grounds, compost, manure, wood-ash, and even fish-tank water. 

Worm castings are the richest natural fertilizer. If starting a worm farm isn’t your thing, they can also be purchased. Bone meal is made from animal bones. Blood meal is from animal blood. Both come in powdered form. 

Organic fertilizer from the store can be expensive. A gallon of fish emulsion fertilizer can cost up to $60. Synthetic fertilizer is much cheaper. A pound of ‘Miracle Gro All Purpose Plant Food’ is only $8. 

Organic fertilizer feeds the microorganisms in the soil, making it healthy and fertile.  Synthetic fertilizer kills the microorganisms. It also builds up as salt, causing earthworms to die and forcing you to add even more fertilizer. Over time the buildup of synthetic fertilizer will start to leach out and create problems elsewhere. If there is a water source nearby, the nitrogen in the fertilizer will generate unwanted plant life, such as algae and water plants, disrupting the ecosystem.

Even when you stop using synthetic fertilizers, it takes up to three years for the chemicals to dissipate. Chemical fertilizer also makes the soil acidic over time. If the pH dips below 5.5 — 6 to 6.9 being ideal — fewer crops will grow.

The choice between organic and synthetic fertilizers is more than a gardening decision; it can determine the long-term health of your soil and the environment.