As the weather warms in spring, so does the ground underfoot making it the perfect time to fertilize your lawn. Fertilizer provides nutrients that may not be naturally available to grass in sufficient amounts or are missing due to soil conditions. It also helps promote new growth and build turf density. But a trip down the fertilizer aisle at your nearest big-box store or local garden centre can be overwhelming. Here’s what you should know in order to properly jump start your grass for the rest of the growing season.
The type of fertilizer used and amount applied will depend on the grass type and time of year. For example, Kentucky bluegrass, tall fescue and ryegrass do exceptionally well in spring and fall when air temperatures range between 60 F and 75 F, so this is the optimal time to fertilize. These grasses, which commonly grow in Canada, tend to slowdown and not need much fertilization in summer months when temperatures soar above 85 F.
Soil pH can make or break a lawn. It is a measure of acidity or alkalinity of soil on a scale of 0-14, with a pH of 7 neutral, 0-7 acidic and 7-14 alkaline. Grass does well in soil with a pH value of 6.5 to 7. If a lawn is too acidic, with a pH less than 5, lime may need to be added once a year to help raise the pH value. If the soil is too alkaline (pH values much higher than 7), it may benefit from sulphur applications to reduce the pH to near neutral.
Nutrients and Ratios
Most complete fertilizers include percentages that represent three different nutrients: nitrogen (N), which promotes growth; phosphorus (P), which stimulates root and seedling development; and potassium (K), which bolsters tolerance against disease and drought. It’s important to select a ratio that provides the right nutrients for the local climate and lawn’s type. A typical ratio of 2-1-1 is common. However, phosphorus should not be applied to soils that show high levels of this nutrient as too much may stunt grass growth.
Most in-store fertilizers are available in three forms: quick-release granules, slow-release
granules and organic slow-release fertilizer. This classification is based on how quickly the nitrogen becomes available to the grass roots in the soil.
Quick-release nitrogen fertilizer helps nitrogen become readily available to grass. Lawn response usually occurs within seven to 10 days.
Slow-release nitrogen fertilizer releases nitrogen over time and lasts longer in the soil.
Organic slow-release fertilizer is made from natural sources. It relies on soil microbes to break fertilizers down and release the nitrogen in the soil over a period of time.
It’s important to carefully follow product instructions when applying fertilizer to avoid ‘lawn burn.’ This occurs as a result of an excess of nitrogen salts with over application. Signs of lawn burn include scorched grass blades. To avoid this, a spreader should be used for even distribution. Once applied, lightly water the lawn to activate the fertilizer.
Fertilization results take time and may not show up immediately, so be patient. Do not fertilize again as it is not good for grass.