This article is a primer on hedgerows: what they look like (and how to recognize the types), how they affect movement, and how they affect line of sight.
Identifying Hedgerows and Hedges[]
The screenshot below shows all three types of hedgey things: high and low hedgerows, and mere hedges. Can you spot the difference? High hedgerows are easy, but it's hard to be certain of the difference between hedges and low hedgerows.
Hedgerows and Movement[]
Hedgerows block all movement: units must find (or sometimes, create) a gap. Hedges don't block movement. Vehicles run right over them; infantry jump them.
Look at the screenshot above again. In test 'A', the tank was given a move command straight through the low hedgerow. The Tactical AI computed the shortest path, and went around the left end of it of the row, crashing through a hedge in the process.
In test 'B'-, the tank was ordered straight through the hedges and it went straight through, creating gaps as it went. (The gaps weren't there when it started.)
Here's some screenshots showing how the TacAI handles movement orders through hedgerows.
Bocage and Line of Sight[]
Hedgerows block all line of sight across them, unless a unit is in one of the action spots bisected by the hedgerow.