Fertilizers are not pesticides. They are not toxic and are not meant to kill anything. They can be applied without gloves and your dog could walk all over your yard directly after application without getting hurt. Heck, little Rex could roll around in it if he wanted to! Fertilizers are non-toxic and are composed of salts. Just like people take supplemental nutrients in the form of vitamins, plants may also need to take supplemental nutrients in the form of fertilizers. Essential macronutrients that plants need include nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur. Plants can’t simply eat a banana or drink some more milk to obtain their daily dose of vitamins – instead, they need to get their nutrients from the soil.
Photo: Everyone wants a lush lawn like this one in East Hampton
Some concerned citizen groups have eliminated the use of pesticides and fertilizers on their lawns and are advocating for others to do so as well. If fertilizers are just plant nutrients, then what’s all the hype about? Well, just like everything in life, a proper balance needs to be struck – not too little fertilizer, not too much fertilizer… just right. A nutrient deficiency may cause a plant to have little or no growth, not photosynthesize properly, or be more susceptible to certain pest problems. On the other hand, too much of a particular nutrient may cause a plant to grow too rapidly and decrease flowering, develop toxicity symptoms, develop other types of nutrient deficiencies, or be more susceptible to other types of pest problems.
Too much fertilizer is certainly problematic for the plant, but environmentally-concerned people are worried about a much bigger problem - nutrient runoff and leaching. If plant nutrients do not go into the soil and are instead carried off by rainwater, they can easily find themselves in one of the many bodies of water that surround Long Island. Too many nutrients in the ocean, bay, or estuary is not good. In very basic terms, what happens is that algae in the water quickly use the added nutrients and then multiply rapidly. “Algal blooms” form which then deplete the levels of dissolved oxygen in the water creating a state of hypoxia. Little oxygen is left for the fishes and shellfish and fish die-offs occur. (Of course it is a bit more complicated than this, but you get the gist.)
So how do we find the amount of fertilizer that is just right? The best way to do this is to take a soil sample and send it to the laboratory for analysis. Soil tests are quite cheap and range from $15 - $65 per sample depending on how much information you want. The other half of the story in protecting Long Island’s water bodies from nutrient loading is to follow the proper guidelines on how to fertilizer. This includes applying fertilizer just before or when plant roots are actively growing. Generally, spring and early fall is when the soil is warm and moist enough for plant roots to be growing and able to absorb nutrients. But now that it is getting cold out, plants are preparing for dormancy and closing-up shop for the winter. Both Nassau and Suffolk Counties have made a determined effort to protect Long Island’s water bodies from nutrient loading. According to county laws, as of November 1st, it is illegal for a landscaper to apply fertilizer to your lawn if you live in Suffolk County. When November 15th comes, it is illegal for a landscaper to apply fertilizer to your lawn if you live in Nassau County. (Trees and shrubs are not included in these laws.) The idea of these laws is to minimize the amount of fertilizer applied to turf grass when it is not actively growing or the ground is frozen. April 1st of next year, lawn fertilization can begin again. Surprisingly, it is still legal for you to apply fertilizer any time of the year to your own lawn - you just can’t have the landscaper do it for you.
Photo: Not fertilizing your lawn after Nov. 1st or 15th helps protect Long Island's water bodies like the Peconic River in Riverhead
So pack up your fertilizer for this season and when spring comes, remember that plants and the environment are like Goldilocks – they want their fertilizer just right.
