Fertilizer is to lawns like food is to people. Put simply, fertilizing gives your lawn the nutrient boost it needs to grow thicker and healthier, while also becoming more resistant to environmental stresses, weeds, and pests. Fertilizing is a massive topic, so consider this your entry-level overview. Of course, contact us or leave a comment below with any questions you might have.
Choosing the right nutrient mix
When buying fertilizer, you’ll see three numbers on the label. These numbers represent the percentage of the key macronutrients needed to feed your lawn: nitrogen (N), phosphate (P), and potassium (K). For example, a 25-5-10 bag will have 25% nitrogen, 5% phosphate, and 10% potassium. The rest of the bag usually contains filler material to encourage even application. This mixture is a good standard mix for the spring.
Choosing the best food for your lawn will depend on your soil, the type of grass you have, and the time of year. Many off-the-shelf mixes will be somewhat tailored to the time of year, but your local landscaper may have a few tricks up his or her sleeve to customize the mix with micronutrients suitable for your specific situation.
Common micronutrients include:
Slow-release vs. fast-release formulas
We typically recommend a slow-release formula mix (usually 50/50) in the spring and summer because the coated granules break down the nutrients slowly over time instead of the short burst of nutrition that quick-release fertilizers provide. Slow-release formulas can be more expensive than fast-release formulas, but you can wait longer between applications and there’s less risk that excess fertilizer will leach away from the root zone.
Fast-release fertilizers can offer some quick results, but you’d want to apply them in smaller amounts and more frequently. You can burn your lawn with a fast-release fertilizer if you use too much.
We tend to use fast-release formulas in the fall, where we’re looking to avoid continued feeding into the dormant season.
Broadcast spreaders vs. drop spreaders
Broadcast spreaders are also known as rotary spreaders (fertilizer drops from a hopper onto a spinning disc that disperses it over the lawn) and are the most common residential spreader for good reason. They can be fairly affordable, they’re easy to use, and they have pretty widely distributed reach. There’s also less chance of ending up with stripes in your yard that can be easily caused when overlapping rows with a drop spreader.
The benefit of using a drop spreader is that there’s very little waste and little chance of getting fertilizer on streets, sidewalks, and driveways. Because of the risk for creating stripes, we recommend broadcast spreaders…but please sweep up any stray granules that wander off your lawn.
There are sprayer options for liquid fertilizers, but granules are the more common option for homeowners so we’re sticking to that type of fertilizer for the purposes of this post.
TIP: If you plan to aerate your lawn, follow up that task with fertilizing. The holes allow for water, fertilizer, and air to directly access the grass roots. It’s like having a feeding tube for your lawn.
When and how often should you fertilize your lawn?
How often you fertilize affects not only your lawn’s appearance, but also its maintenance level. The more you fertilize, the more you’ll need to mow, for example.
In most cases, you’ll see the best results if you fertilize your lawn about every 6-8 weeks during the active growth period. That usually means 1-2 light applications in the spring (April and May) and 1-2 in the summer (June and July — not in the dead heat of mid-to-late summer, though) and 1-2 heavier applications in the fall (October and November), depending on whether or not you choose to fertilize in each season and whether or not you use a slow-release or fast-release formula.
If you’re not up for the extra mowing that comes with healthy, well-fertilized lawns, you could consider just one application in the spring and one in the fall. Just keep in mind that without the extra nutrients, stressful weather situations (drought or harsh winter) can take a more significant toll on your lawn.
Fall, in particular, is a very important time to feed cool-season grasses in Ontario, keeping them growing longer into the cool weather and providing the reserves needed for quick “green-up” in the spring.
TIP: When fertilizing your lawn, remember that too little is better than too much. If you apply too much fertilizer, not only can it leach through the soil and make its way into our precious groundwater and waterways, but it can also weaken the lawn.
What to do after fertilizing
Water is vitally important because it washes the fertilizer off the tips of the grass blades down into the soil. It’s best to fertilize immediately before a rainfall or make sure you water the lawn thoroughly afterward. Be careful not to apply fertilizer before a heavy storm though, or you could wind up having the fertilizer wash away into storm drains and streams. Just in case it doesn’t go without saying, also avoid applying fertilizer during a drought when the lawn has browned or withered from lack of moisture.
Water aside, it’s also a good idea to keep kids and pets off the lawn for the amount of time recommended on the label (or by your landscaper), which is usually 24-48 hours.
For our organic-loving friends out there
If chemical-based fertilizers just aren’t your thing, you still have options. Fertilizers made of all-natural materials can indeed feed your lawn just fine, but they tend to be less saturated with the key macronutrients (nitrogen, phosphorous, potassium) than industrially refined fertilizers. These organic mixtures also tend to come at a premium price point.
An alternative to organic fertilizer, which comes standard in our regular mowing packages, is to use a mulching lawn mower to chop up grass into fine particles that then break down on the lawn (also known as grasscylcing). Over the course of a season, this provides much-needed nitrogen supplies, but you might not get just as much of the benefits of the fully balanced mixes.
Like we said earlier, this is a massive topic. If you’re interested in fertilizing your lawn and would like to learn more about a tailored formula specific to your lawn’s needs, please contact us and we’d be happy to help.