Got Weeds?

Submitted on May 31, 2017

Although there are many environmental and other benefits of growing a thick, lush green lawn, the primary motivator for most people to either hire a professional or look after things themselves is weeds!

Sometimes as a first step you will see homeowners mechanically removing weeds from their lawns either by hand-pulling or utilizing a range of commercially available weed pulling tools. Most weed pulling tools will leave behind a hole like an aerator. Ideally these holes need to be filled with grass seed so the weed does not re-establish itself. Mechanical weed removal is practical only if there are a few weeds to remove in a relatively small area of the yard. More often than not, homeowners need to employ other strategies.

With the majority of Canadian provinces opting to ban the use of traditional herbicides, these days weed control is more than just a quick spray once or twice a year. Whether you are using newer iron-based control products or traditional weed controls, the most sustainable form of weed control has always been to grow a healthy, lush green lawn that basically out-competes or crowds out weeds from encroaching or taking over.

At one time, applying older traditional weed control products in spring and fall usually did a reasonably good job at keeping the weeds down; regardless of how healthy the lawn was. Expecting the same results applying newer iron-based products the same way is simply not realistic because the newer weed control products work differently. Traditional weed controls had a systemic action, allowing for literally a few drops to be absorbed by the plant for complete control. Conversely iron based products require a substantially larger dose of chelated iron which weakens the plant; usually blackening its appearance. Sometimes, the weeds can be weakened enough at the first application for complete control. However, more often than not the initial shot of iron simply weakens the plant. A 2nd application of iron within 3-5 weeks of the first usually finishes off what the first application started. The critically important factor however is what’s going on with the grass in between the weeds. If the grass around the weeds is thin, sparse and weak, it almost doesn’t matter how much or how often chelated iron is applied because without competition, blackened/weakened weeds will ultimately persevere and continue to invade the lawn.

Rather than relying solely on calendar-based herbicide treatments, a more holistic approach that focuses on optimum plant health is the best plan. Along with proper mowing (mow high, sharp blade, adhere to ⅓ rule) and watering (deep, infrequent, morning only) covered in the “Top 6 Things to Maximize Your Lawn Care Dollar” article, 3 other essential considerations include:

  1. A sound fertility regime
  2. Core Aeration
  3. Over Seeding

These 3 things build up the density of the turf which will go a lot further to keeping your lawn weed free. When one of these areas is neglected, the lawn can become thin; creating the opportunity for weeds to re-invade the lawn.


A Sound Fertility Regime:

At the foundation of every vibrant, thick, lush, green lawn is a sound fertility program. Neglecting to properly fertilize almost guarantees weeds will make their way into the lawn.

Every fertilizer bag displays 3 numbers; which identify the nutrient levels of the product. So a fertilizer such as Weed Man’s 24-0-4 product means 24% Nitrogen, 0% Phosphorous and 4% Potassium. The importance of these 3 nutrients can best be described with 3 words….”Up, Down, Around”.

  • Nitrogen (Up) is what gives the visible part of the lawn (grass blades) its deep, rich green colour. It is needed most by the grass plant in terms of an added nutrient.
  • Phosphorous (Down) focuses on root development. Since phosphorous is naturally present in most soils, it is not added (except for newly seeded lawns requiring a starter fertilizer with a large middle number (i.e. 10-20-10)).
  • Potassium (Around) is needed for stress tolerance and general all-around plant health.

The other thing to consider with any fertilizer product is how quickly it releases. Generally, the longer the release period, the more expensive it is. For example Weed Man’s programs use products ranging from 65%-85% slow release content; depending on the blend. Slow-release fertilizers actually green up the lawn at slower rate. However, a slower more even feeding produces a much healthier plant in the long run.


Core Aeration:

An aeration machine punches a series of evenly spaced holes throughout the lawn. These holes not only provide a direct entry way for nutrients, grass seed air and water, but they also help overly thick, matty lawns (think new sod) break down their “thatch” layer to help the entire lawn establish a deeper root system that is more embedded in the ground instead of growing almost on top of the ground. Increased air circulation also helps to de-compact tightly woven soil (such as clay) and encourage “microbial activity” (soil micro-organisms) which in turn creates a far more fertile environment for your lawn.


Over Seeding:

Introducing newer varieties of grass seed to your lawn can help strengthen it; especially if the seed used is “certified” (high quality). As a property ages over time, changing surroundings such as growing trees and shrubs, new fences, kids play equipment and other adjacent structures can adversely affect that once pristine new sod that was the pride of the neighbourhood when the house was built. Over seeding provides an opportunity to re-assess the changing needs of the lawn by choosing more appropriate seed varieties. Newer grass seed types are often more resilient because they contain something called “endophytes” which are basically natural micro-organisms that help the grass better withstand pest and environmental pressures. Over seeding your lawn in conjunction with aeration is an ideal scenario because the seed falls into the holes made by the aerator.


So again, too often people focus strictly on the spraying as the primary means of controlling weeds in their lawn. As much as traditional weed control products might help win small battles, the ultimate way to really win the war on weeds in your lawn is to focus on all 3 of these things to keep your lawn as thick, green, lush and vibrant as possible every year.





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