By Courtney Ahnert, Clean Water Institute Intern, Summer 2021
It’s common practice to use fertilizer to help your garden grow to its full potential. However, the components of plant fertilizer that make it work so well also have some detrimental effects when they are used in excess and then allowed to seep into water sources through stormwater drainage and other forms of runoff. Fertilizer contains large amounts of nitrogen and phosphorus, and when these get into lakes and streams, they spur increased algae growth and plant productivity, which can choke out fish and other aquatic life and hasten eutrophication of lakes. However, there are fertilizer alternatives and ways to keep fertilizer out of our water that you can use to ensure the safety of your local watershed.
Compost is a great alternative to store-bought fertilizer, and you can make some at little to no cost! Simply get a bin or other large container and throw in leftover fruit and vegetable scraps, coffee grounds and used-up loose-leaf tea (roses especially love coffee grounds!), and eggshells (great source of calcium- make sure you crush them up before throwing them in your compost bin). Add some soil and earthworms to your compost bin too if you can, because earthworms are good at chewing up and processing scraps in order to turn them into soil faster. Compost helps naturally provide your plants with all the nutrients they need, without the big risk to waterways that excess fertilizer poses.
Raised Beds and Reasonable Fertilizer Doses
If compost is not an option for you and you must use fertilizer, there are a couple of ways that you can minimize the runoff/contamination risk while still having a fruitful garden. One way of doing this is to plant your garden using raised beds, which puts a barrier and a bit of distance between your fertilized soil and potential runoff areas. Another option to use in conjunction with raised beds is a proper dosage of fertilizer. A little fertilizer really goes a long way for your garden. A good rule of thumb is to use fertilizer sparingly, but frequently, because if you pile it on all at once, most of it will get washed away and harm waterways instead of nourishing your plants. Also, if possible, use natural fertilizer like bone meal or blood meal instead of synthetic fertilizers.