In a natural setting such as a forest, a meadow or a floodplain, nutrients are constantly being recycled. Even unfortunate events such as an animal dying are huge sources of nutrients for plants and soils. In a managed residential landscape, we are constantly removing what we call debris. Another natural event we tried to control is flooding and water runoff. Rainwater contains good sources of nitrogen which is the number one most needed macronutrient. We want our landscapes to look neat and clean. However, our plants, lawns and trees still need nutrients. To keep them healthy we need to supplement them, much like we supplement our diets by taking vitamins. Taking vitamins is a good analogy for how we should think about fertilizing or trees, lawns, and plants. There are several different kinds of fertilizers with different balances of nutrients. Many fertilizers contain beneficial bacteria and food to promote bacteria. This is akin to taking prebiotics and adding fiber as part of your diet. Applying the wrong combination of nutrients can create just as many problems as not applying nutrients. It is important to consult an expert and use soil testing and visual clues as to how your plants and trees are growing.
One important piece of advice we try to teach our clients is to not bag their leaves in the fall. Instead, use a mulching blade and allow those nutrients to return to your dirt. This is the same you should not be bagging your turf clippings. Spectrum Analytics is one of several soil and tissue testing companies out there. They reviewed 100 municipal leaf samples collected from across New Jersey. Their findings reveal that while nutrient concentrations vary considerably, “the application of 20 tons/acre of leaves would add on average 400 pounds of nitrogen, 40 pounds of phosphorus, and 152 pounds of potassium. Assuming values of $.30/pound N, $.23/pound P, and $.18/pound K, the nutrients from this example are worth $156.56.” That is incredible and only considers the three macro nutrients. Leaves are full of other macro and micro nutrients! Furthermore, it is exceedingly difficult and expensive to add supplemental carbon to a residential landscape. Carbon and larger pieces of debris are important for the soil structure and bacteria. The timing of when leaves fall is correlated with when trees, plant and grass have their most root growth. Joseph, Heckman. “Agronomic Library.” Plant Nutrients in Municipal Leaves, Spectrum Analytics, 1988
In addition to mulching in leaves, applying quality wood mulch is a great way to supplement your landscape in a way that nutrients are cycled in a natural setting. Once you are in a habit of adding these natural sources of nutrients, most of your trees and shrubs will be excel. Grasses, which are meadow species, get a lot of nutrients through periodic fires and through excrement left by grazing animals. The species of grasses we use in residential lawns are even more needy than native grasses and our landscape trees and plants due to a shallower root system. For these reasons, lawns do require supplemental fertilization for maintaining color and vigor. Practices such as mulching in leaves and grass clippings will reduce the amount of extra nutrients needed and will help to avoid ‘nutrient crashes’ where the lawn goes hungry in between feedings.
For more information on fertilizing lawns and plants, give Thrive a call!