Written by David Chalmers, former Professor & SDSU Extension Turfgrass Associate.
Many home consumers do not know the size of their lawn area before they visit the garden center to purchase fertilizer and other lawn care products. This often leads to a “helpless” feeling about making the purchase, buying the wrong amount of product, misapplication and inconsistent results. Knowing the size of the lawn is the basic principal of “measured” lawn care, which is environmentally sensitive!
Examples of how lawn care products are recommended include:
- Lawn care products will recommend application based upon the amount of product to apply per 1,000 square feet or the package will state how much area it is meant to cover in square feet.
- Extension recommendations and soil test recommendations for lawns suggest nutrients be applied in an amount per 1000 square feet.
- Fertilizer products can be formulated with plant protectant chemicals: as in herbicides in “weed & feed” products or a fertilizer insecticide combination product. Yet, to effectively use these products there should be a “measured” need for both the pesticide and fertilizer at the time they are applied. To control the pest, these products must be applied at the correct rate per 1000 sq. ft. for pest control. If you don’t have a pest problem in your lawn then use regular fertilizer.
- Pesticides may be formulated in a concentrated way where the amounts must be measured in liquid or dry ounces per 1000 square feet and applied with a type of sprayer (hose-end or backpack).
The following true story demonstrates this very basic principal of “measured” lawn care!
It’s a while back when my neighbor called from across the street to ask a question regarding making a fertilizer application to his lawn. It seemed that he had purchased 4 bags of a product that was a combination fertilizer product and insecticide. Each of the bags stated that they covered 5,000 square feet. Yet there was one problem; he did not know how to measure the size of his lawn to determine how many bags he needed to apply.
I have to expect that he is not alone among the home consumers purchasing fertilizer or plant protectant (herbicide, insecticide or fungicide) products for their lawn or garden. When using the fertilizer-pesticide products, their application to a known area (in this case 1 bag per 5,000 square feet) makes certain the appropriate amount of pesticide is applied to actually obtain control of the pest.
So what I did was to show my neighbor how to measure his lawn. I first chose to demonstrate the “step” method to estimate the size of his lawn. Being a golfer I have a step that is very close to 1 yard (3 feet) in length. I use that to judge the length of golf shots and distances in yards. To calculate lawn areas I first had my neighbor pace off the width of his front lawn and tell me his total number of steps. He took 17, but he did not know how long his step was and he noticeably stretched his step, thinking it would be closer to being right. Well my “pretty well calibrated” step paced off the yardage at a 22; a difference of 5 steps. Converted to feet (22 paces at 3 feet per pace), my estimate came out to be 66 feet wide. If my neighbor assumed his step at 1 yard (his step was obviously longer than a yard) then he would have assumed a distance of (17 steps at 3 feet per step) 51 feet – he would have underestimated by 23 %. So this was a very teachable moment. I then put down a tape measure that showed him how long his step would need to be to come pretty close to 3 feet or one yard.
So for each dimension we stepped off he converted his steps (1 yard) to feet by multiplying by three. I went behind him to check his distances. Then each area was multiplied as needed according to its shape and added up to total 8,000 square feet of lawn area. So he only needed to purchase two bags of the product, not four!
Most lawn care products are sold at recommendations of how much to apply per 1,000 square feet. It is a real challenge to purchase the right amount if the size of the lawn area is unknown!
Not knowing the size of your lawn usually results in:
- Buying too much fertilizer, herbicide (for weeds), insecticide, or fungicide (for lawn diseases).
- Left over products must be stored for next use or disposed of if it isn’t ever used again.
- Applying too much lawn product may result in more mowing (fertilizer), reduced plant health (fertilizer & pesticides) and off-site effects (nitrate leaching/runoff, phosphorus runoff, and pesticide injury).
- Not buying the recommended amount of fertilizer or pesticide to treat the lawn area often results is not achieving the desired fertilizer response or pest control.
- An ineffective use of your time and money.
To calculate the amount of square feet in lawn areas:
- Use a tape measure for the most accurate measurement. But if one is not available you could use the “step” method to obtain a good estimate.
- First pace off distances and count the total number of steps.
- You could put down a tape measure work out what your normal step is in feet. Practice a bit on whatever your comfortable step length is and check distances from time to time.
- Convert your well-calibrated (practice makes perfect) number of steps for a measurement in feet by multiplying steps times the distance of each step in feet.
- Example: 22 steps at 3 feet per step equals 66 feet.
- Multiply each area as needed according to its shape to convert to square feet.
- Add up the individual areas to obtain a total square feet of lawn area.
Lastly, draw a diagram (see the image below) that shows the house and each lawn section and the total square feet for each area. This can come in handy in both purchasing and applying lawn care products. Also knowing the area of garden and ornamental beds will also be useful in purchasing mulch and other products.
Above: An example of how to break down the different areas of your lawn into measurable chunks.
Encourage all home consumers to measure their lawn area with a “calibrated” step method or with a long tape measure to be really accurate. The GREAT thing is that home consumers only need to accurately measure their lawn once and then they have it when they go to the garden center. Home consumers who know the size of their lawn, garden and ornamental beds are much more likely to purchase the correct amount of fertilizer, plant protectant chemicals and even mulch! It’s the first “step” to measured lawn care!