For daily wit & wisdom, sign up for the Almanac newsletter.
Grow a great lawn without using as much fertilizer! Like a lot of things, fertilizer is expensive right now, so here are worthwhile actions that you can take to reduce your lawncare costs while growing a healthier lawn.
The best defense is a good offense. To maximize the health and beauty of your lawn while minimizing fertilizer use, consider: the right grass species, the health of your soil, and cultural practices. Learn more about the basic turf fundamentals that everyone should follow to grow a healthier lawn.
I. Choose The Right Grass Species
How much you fertilize and water your lawn depends on which grass type you select. Here are the main cool-season turfgrasses:
If you really want a low-maintenance lawn, consider that the turfgrass species you grow can lower the amount of lawn fertilizer.
Kentucky Bluegrass and Perennial Ryegrass require 2 to 5 pounds of nitrogen fertilizer per 1000 square feet every year just to maintain their appearance! That means two to five applications annually. However, a Fine Fescue or Turf-type Tall Fescue require half of this, needing 1 to 2 pounds annually. Fescue can also handle drought better, requiring less watering.
If you don’t want to use any fertilizer, a “hard” or sheep fescue would be a good choice for ground cover. No, the turf won’t have the same soft carpet appearance as a Kentucky Bluegrass, but you will have even plant coverage to protect the soil from weeds and erosion and be maintenance-free.
Adjust for Sun Versus Dappled Shade
Certain grasses such as fine fescues grow better in shade; they can be used in partial shade or dappled shade spots. Or, mix Kentucky Bluegrass with Creeping Red Fescue in these areas for a more even look.
Speaking of shade, don’t fertilize all parts of your lawn equally. Not all grasses grow at the same speed. Grasses growing in partial or dappled shade grow more slowly, so they certainly don’t need the same amount of fertilizer or water.
II. Maintain Healthy Soil
As with vitamins for your own body, you do not want to over-fertilize your grass. Too many nutrients simply go to waste and can even do damage, making your lawn’s health worse. It is important to only apply as much fertilizer as your soil can hold or your lawn can use, no more and no less. So how do you know what your soil needs?
Know Your Soil: Get a Soil Test
Not all soil is the same! Don’t make the assumption that a thin lawn simply needs a standard chemical fertilizer (N-P-K). Perhaps you need a fertilizer with extra micronutrients. Understanding your soil will reduce unnecessary applications and reduce costs.
Soil tests tell you how many nutrients are in your soil available for plant uptake. “Heavier” soils with greater clay and silt contents can hold more nutrients than “lighter” soils containing more sand.
If your soil has a low nutrient holding capacity (i.e., cation exchange capacity), then more fertilizer is needed in order to reduce nutrient loss.
Through a soil test, you may find out that your lawn doesn’t need fertilizer. If that is the case, listen to the test results! Do NOT overfertilize as this isn’t healthy for the plant.
If your soil test tells you to amend your soil, take proper steps. A dense lawn cover is the end goal; it not only uses less chemicals in the long-run but also is the most storm-friendly lawn, avoiding run-off into our streams and water ways.
Adjusting Soil pH Your soil test will tell you the soil pH, which can influence the availability of soil nutrients. Optimum pH for turf growth and nutrient availability is slightly acidic (i.e., 5.5 to 7). Soil pH can be corrected by applying certain amendments and/or fertilizers.
Increase soil pH by applying lime
Decrease soil pH by apply sulfur or sulfur-containing products
Adding Nutrients Nitrogen, Potassium, and Phosphorus (N-P-K) are the most important nutrients for plants. It is important to make sure the soil is sufficient in these elements. Calcium and Magnesium are sufficient in most soil types, though sandy soils may need supplemental Ca and Mg applications.
Fertilizer can come in granular or liquid form. Liquid fertilizers have become increasingly popular because it is easy to apply more evenly with a sprayer, no matter whether you have a small or a large yard. Granulated fertilizer can get picked up by a lawn mower when the grass is mowed as well as eaten by birds and wildlife; granular fertilizer also seems to run off more easily in heavy rainstorms.
To avoid overusing fertilizer, it is important to water-in fertilizer applications by applying irrigation after fertilizing turfgrass or timing fertilizer applications prior to light rainfall.
Soil Structure A soil test will tell you if you have heavy, claylike soil or sandy soil and how to adjust. A heavy clay soil will be very compacted, which doesn’t allow air to get to the roots or water to absorb into it, which means that the grass can’t take up nutrients.
Many soils can benefit from more organic matter. One way to amend the soil and reduce fertilizer is to top dress your lawn with organic compost, about 1/4 inch thick. Compost is a nutrient-rich form of fertilizer (and free, if you compost yourself!). This will also save on fertilizer application costs.
If you have compacted soil, it’s best to first loosen the soil to provide air circulation to the roots; this is best achieved by renting a “core aerator,” which is a machine that pulls cores that are several inches long out of your lawn. After core aerating, top dress the lawn with compost. Note: Avoid adding sand or peat moss to clay; they can make those problems worse! Learn more about clay soil.
III. Be Smart With Cultural Practices
The goal of your mowing regiment should be to maintain healthy grass. Every time that you cut your grass, you are injuring the turf plant. Let’s learn to minimize the injury and the corresponding stress on the plant, which will result in a healthier, greener lawn!
Most common lawn grasses prefer a higher height of cut, usually at least 3 inches. This leaves enough leaf material present for the plant to photosynthesize at an appropriate rate to ensure good plant health.
Mowing the grass at 3 to 3.5 inches tall also slows the rate of runoff and builds a larger root system which can absorb more water, be more tolerant to drought, prevent erosion, and suppress weeds.
Don’t allow grass to get too much taller; it’s important to mow frequently enough to minimize clippings left on the turfgrass surface.
Return Grass Clippings to the Lawn
Mowing grass clippings and leaves back into the lawn provides about 25% of your lawn’s total fertilizer needs! This could be equal to one application of fertilizer if the lawn is getting three applications a year.
Clippings from an old leaf generally contain all the nutrients required to grow a new leaf: about 4% nitrogen, 2% potassium, and 1% phosphorus.
A mulch-mower is ideal for retaining and spreading clippings on your lawn. Don’t worry: The clippings decompose quickly, not only providing these important nutrients but also providing a beneficial food source for bacteria in the soil! This technique can significantly reduce or eliminate the need and cost of nitrogen fertilizers.
Note: It’s a myth that clippings contribute to thatch or significantly contribute to phosphorus runoff. In fact, grass clippings are feeding the beneficial bacteria which decompose thatch for a healthier lawn.
Your turfgrass needs about one inch of water per week. If you don’t have a rain gauge, one DIY method is to put out a few empty tuna cans in several parts of your yard. If your grass doesn’t receive enough rain, you’ll need to water it manually; split watering into multiple applications. There’s no need to overwater or you will only increase fertilizer run-off.
If your grass isn’t watered in 3 to 4 weeks, it will turn brownish. This is natural; it is not dead but simply dormant. Stop watering and don’t apply nutrients when the turfgrass is not actively growing.
During normal rainfall: If the water runs off the top of your soil and doesn’t absorb, this is another clue that you have compacted soil; the water will “run off” with the nutrients, fertilizer, and soil.
Adjust Your Fertilizer Timing
Many folks get the timing of fertilizing all wrong; don’t trust the flyers from lawn companies who want your business and will maximize applications, no matter what type of soil or seed you have.
To maximize plant uptake, fertilizer nitrogen applications need to coincide with the most favorable growth periods. Over 70% of nitrogen should be fall-applied for cool-season grass. Therefore, if you’re only going to fertilize once a year, it should be in the fall! If you fertilize twice, it should be in the fall again—early fall and late fall. We would recommend using a liquid fertilizer three times to maximize plant uptake.
Late spring/early summer,
Early fall, and
Some Words on Weeds
Some of the same tips for reducing fertilizer use are applicable to weed control. Weeds grow in turf because of: compaction, poor fertility, shade, and subpar cultural practices. When it comes to weeds, remember:
Pre-emergent control of weeds is easier.
Mow turf at least 3 inches high.
Time mowing to prevent weeds from going to seed.
Maintain ideal soil and turf fertility through practices discussed above.
Avoid compacted or bare soil; a dense turfgrass stand limits weeds.
Spot spray and over seed to encourage turf density.
In conclusion, take these steps to use less fertilizer: 1. Choose the right grass seed for the level of maintenance you can handle as well as sun/shade; 2. Improve the health of your soil so the plants can efficiently take up nutrients without overusing fertilizer, and 3. Keep up good cultural practices from using grass clippings to mowing high to timing your fertilizer applications to match growth periods.