How Knucklehead Edging lawn edging sections are joined together.

Typical failure of plastic lawn edgings.

The "knuckle" overlaps the joint
 and connects to next section.

The next section receives the knuckle
 from previous section reinforcing the joint.

Most plastic lawn edging are milled, at the ends, to create overlapping "tongues". When the manufactures remove the excess material to create these tongues they are removing structure integrity of the material. Even when the tongues are properly aligned and secured with the recommended hardware, failure is imminent! The tongues are weak and too thin! The tongue will actually break off, from the edging or the screws, destroying any chance to re-install at a later date.
The Knucklehead Edging connecting joint consists of a left side and a right side that fit together like a puzzle! The knuckle extends 4 inches from one section and is received by the next section which has 4 inches of knuckle removed. For further reinforcing, Knucklehead Edging uses a "backing plate", that still allows for the installation of low voltage wiring and drip tubing, while added structural integrity to the joint.

Knucklehead Edging overlapping connection.

Why do the joints on lawn edgings break?

This is one of the most common issues with plastic lawn edgings on the market today! Why does this always happen? Even on my own installations, I was never shocked to see the the joints breaking and heaving out of the ground.

There are multiple factors that contribute to this problem. 

• Expansion and contraction of the edging material.

• Ground movement 

• Staking practice and type of stake used

The reason for this is simple! All edgings will expand and contract. Yes, even concrete curbing and metal edgings, just less than plastic edgings. The ground expands and contract also. The stakes are the only part of the edging system that are stationary. With the stakes being stationary, the edging is forced to expand and contract between each stake. This force will either break the hardware holding the stake to the edging or lift the stake out while still being connected to the edging. Either way, it is almost impossible to get the edging back to its original place of installation.

The answer is to allow for lateral movement and pre-forming.