Analyzing Aeration Plugs


An essential understanding of the soil beneath a lawn determines what maintenance procedures to continue on with or to change. Parts of the soil have an impact on the whole lawn. Analyzing aeration plugs can help you to identify those parts (most likely missing) and guide you to formulate an effective maintenance plan for your lawn next season. Creating a balanced soil structure and food web that will aide in sustaining a lawn while conserving resources is the ideal outcome to any lawn maintenance program.

What do aeration plugs in Douglas County consist of? Aeration plugs fall into three main categories: Spongy Plugs, Clay Plugs, and Top Soil Plugs. Examples of each type of aeration plug, as well as a Highlands Ranch lawn that has been top dressed the past two seasons, are featured in the picture boxes to the left.

Spongy Plugs


When spongy plugs are compressed between your fingers, they bounce back to their original length. The thick mat of roots is the result of growing on top of themselves as if the ground beneath the roots is too hard to grow into. Very little top soil or clay exists on the plug end. I’ve observed these lawns respond well to fertilizer but require frequent watering to prevent them from drying out.  These yards probably didn’t have much compost rototilled into the ground before sod installation. After several years, the root zone becomes so thick aerators have difficulty punching through deep enough to reach the dirt to relieve soil compaction. Grass struggles to grow when roots are not part of the soil food web.

Clay Plugs

Clay Plugs are perfect for making ashtrays or pottery. The heat of summer acts like a kiln and the lawn turns into a brick. The grass roots can barely penetrate into the clay especially if these lawns are not watered properly. Organic matter is scarce and the plugs appear gray in color. Aerators barely penetrate these lawn when they are dry, but when wet, the sticky plugs clog the aerator tines and push into the clay to make holes without popping a plug onto the surface. Soil compaction is not relieved in this case. Worms resort to blasting if they desire to take up residency in these yards. These yards are less responsive to fertilizer and water tends to runoff even the slightest slope. Weeds usually find their way into these yards amidst the thinning grass aside.

Top Soil Plugs

Top Soil Plugs are black and crumble between fingers exposing a deep root zone throughout the plug. Top Soil Plugs contain organic matter, microorganisms, sandy loam and evidence of worms (usually in pieces). These lawns respond very well to organic fertilizer and requires fewer deep watering sessions. Water easily percolates and gets absorbed by the organic matter instead of running off. This soil sustains the lawn because it contains a thriving food web capable of feeding the grass. With regular organic fertilizer applications, the soil’s microorganisms are fed and continue to feed the lawn thus completing the soil food web cycle. In essence, you’re feeding the soil which in turn feeds the grass.

What maintenance program will improve all three types of lawns? Top Dressing is the process of spreading a thin layer of composted sandy loam (topsoil) over the entire lawn following an aeration filling the holes with fertile soil grass can grow in. The composted part of top dressing mix adds organic matter rich in nitrogen and water absorbing material. The sandy loam creates a more porous soil to allow water to soak in and reach the root zone. Sandy loam also creates space within the soil for microorganisms to do what they do best - break down organic matter into usable forms of food for the grass. Organic matter and sandy loam breaks up clay so roots can penetrate deeper into the soil.

Nolan’s Lawn Service believes the soil beneath a healthy lawn contains a thriving food web loaded with microorganisms, organic matter, nutrients, sand, and worms to sustain the grass while conserving resources. Top Dressing a lawn with fertile soil on a regular basis creates the proper soil structure and food web to improve every aspect of your lawn maintenance program toward producing a lush eco-friendly lawn.

Want to Top Dress?


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