Lawn & Garden Fertilizers
Healthy lawns, trees and shrubs add to the beauty and value of a home. Maintaining healthy lawns and landscape plants often
requires the use of fertilizers which can cause water pollution. Fertilizer carelessly applied to lawns can be a waste of the money and can lead to major problems for the Kinnickinnic River. Fertilizer programs should always begin with a soils test
to avoid over-application. Excess fertilizer will typically run off the lawn into the street and ultimately the Kinni.
Starting in April 2010, usage of phosphorus fertilizer in Wisconsin was banned (with a few exceptions). Most lawns do not require phosphorus.
For trees and shrubs, nutrient requirements vary from plant to plant. In general, nitrogen promotes leafy top growth; phosphorus is used for root development and potassium is necessary for winter hardiness, disease resistance and overall plant durability. Typically fertilizer should be applied in late fall or early spring when plants are dormant. Fertilizing in early fall may stimulate growth that might be killed in winter. Similarly, fertilizing in late spring stimulates growth that depletes food supplies and weakens the plant.
Tips to Remember:
- Always start with a soils test.
- Healthy trees and shrubs do not require annual fertilizer applications.
- Sweep all fertilizers off paved surfaces.
- Pesticides are often unnecessary. Application can waste money as well as pollute the river.
Rethinking the norm
Many every day activities that occur at our homes have the potential to harm the Kinnickinnic, such as:
- Fertilizer and pesticide applications can cause harm when over applied before a heavy rain.
- Leaves and grass clippings that are not properly disposed of can also wash into the river, thereby overloading the river with the phosphorus and nitrogen that they contain.
- Auto maintenance: Anything that drips from your car (oil, gasoline, antifreeze, etc.) will likely be flushed into the street and ultimately to the river. Five quarts of oil can create a slick as large as two football fields and persist in mud or plants for over six months.
- Failure to read labels can result in application of pesticides that do not target the pest you are having a problem with. This results in an unnecessary application which wastes your time and money as well as potentially harming the environment.
- Failure to read labels can also lead to applications at the wrong time which can have the same results as applying the wrong chemical.
- If a label says not to apply if rain is in the forecast, heed to that recommendation.
Is a soils test complicated?
Taking a soils sample is easy, you simply need to take soil from 3-4 places in your yard, mix it together and submit two cups of this mixture to the address provided with your sample kit instruction sheet. With each soils test you get an analysis of the current nutrient content of the soil and recommendations of type and amount of fertilizer to add.
Every three years is suggested.
Where do I get a sample kit?
To request a soils kit be mailed to your home call the UW-Extension office in Ellsworth at 715-273-3531, ext. 6663, or in Baldwin at 715-684-3301, ext. 5. Soils tests cost $15 but can save you time and money by detailing when and how much to fertilize your lawn.
- A healthy lawn needs about one inch of water per week applied all at one time. Frequent, light watering favors shallow roots, making lawns less tolerant to dry periods.
- Using a can on the lawn can help you gauge when you’ve watered one inch.
- Excess water can keep the soil too moist which damages roots.
- Established lawns can survive several weeks of dormancy with no water.
- The City restricts lawn watering to before 8 a.m. and after 7 p.m. on odd/even days (corresponding to the house number)
- Set mower height to 2 ½ - 3 inches to provide more leaf area to shade the soil. Weeds thrive in bare soil but suffer in tall, dense turf.
- Mow frequently. It’s best not to remove more than 1/3 of the leaf blade at any time. Removing more than 1/3 the blade shocks the lawn and can stop root growth. In addition, long grass clippings don’t break down as easily.
- Leave your grass clippings on the lawn. Clippings can provide between 20-50% of the nitrogen needed by your lawn each year.
- Sharpen your mower 2 - 3 times a year. Dull blades tear the lawn leaving it at risk for diseases.