Garden paths: a metaphor for flowing water
In nature, there are generally two ways to get from here to there: follow the contour lines of the terrain where it's steep or follow the path of a river where the grade is gentle.
Both offer useful options when it comes to designing a landscape involving native plants if the goal is to achieve a "natural" look. And which is used can depend a great deal on the specific type of habitat that's being created or worked with.
In steep terrain, often replicated in alpine-style gardens, narrower pathways work along geologic contours in an effort to make the trek as comfortable as possible. This leads to a charming circuitous route, of course, as it passes many moments of display opportunities. If the existing terrain is steep, the landscaper must work with a host of situations that might include boulder outcrops, precariously rooted trees, rough footing, and slippery slopes. But few are so fortunate as to have to carve out a path in a mountainside or on a high ravine.
In more gentle terrain, ranging from a zero gradient to perhaps eight or ten degrees, options grow, but careful planning is still at the top of the agenda. It might be an ordinary back yard lawn today, but it'll be wilderness tomorrow. Sort of. Natural habitats are chaos, random and governed by unexpected circumstance. The shrewd native plant enthusiast understands that chaos needs to be controlled for visual impact and recognizes that, by definition, a garden is a compression of nature and not an exact representation. Were it so, the garden path might stretch for many miles.
If the terrain has a grade, or, better, is rolling, the least expensive question to ask is how a small river might run through it. Start at the top and look for the natural course of water to the bottom. A stream creates a marvelous metaphor for a garden path for several reasons:
Water moves downhill, its course defined by the path of least resistance. This is rarely in a straight line and often with meanders. It'll be the least resistant for foot travel, too, and create interesting vantage points.
Water goes around obstructions. This sounds all too obvious, but give it some thought. If you create a little berm or put in some decorative rock, you create a logical reason for the stream (path) to turn. If you already have an obstruction, work with it.
Water goes faster in narrows, slower when the course is wide. The same is true of garden visitors. Paths often narrow a bit between garden rooms specifically to encourage people to move along quickly. This can be done with mini-ravines or plantings of tall species near the path. If combined with a curve, it enhances the mystery already caused by the partially obstructed view of what's ahead.
Water goes faster on the outside of a curve, where it erodes the bank, and slower on the inside - where it often deposits alluvium. Alluvium are sands, silts, clays and sometimes gravels that create fertile land, often growing into flood plains over time. These are usually river sections where there's more light and a lot of moisture-loving herbaceous perennials. On the opposite side, the river will cut into the earth, shearing soil away and will try to build a steeper grade. This is the side of the "river" for plants that suggest such a landform. For what it's worth, the radius of a river bend is usually three times the width of the river and meanders occur on opposite sides along stream length equal to eleven times the stream width. So if your path is five feet wide, the logical radius of the bend is 15 feet and the next bend should be 55 feet of "river" down stream and on the opposite side of the previous. That's not so far; a full U-bend with a 10-foot radius would be about 32 feet long.
Just as a river is level from side to side, and garden paths should be, too. With the exception of abrupt changes in grade, like waterfalls or rapids, the rate of descent also tends to be relatively even. To replicate this in the landscape, the rise of a path would be a nice smooth line, smooth surfaced, and graded to be level from side to side. If that principle collides with bumpy terrain, make a cut or build up path grade to keep the path true.
These principles apply for either meadow or forest garden settings, although the meadow would probably involve fewer grade changes but larger and broader planting areas. Forest conditions tend to work in pockets of plants, so the grade changes might be more pronounced and the path more twisting.
A potentially helpful device to develop a path surface is a length of sturdy four-inch pipe, the kind used for sewer lines. When cut to a length used for the width of a path, the pipe serves as both a grader, roller and simple tamper and the means to measure level from edge to edge when finishing the path surface. In a perpendicular direction, it can then be used to discover dips and bumps in the linear line of the path. Because it's relatively inexpensive, light weight, and lasts forever, this simple device should be fixture among shed tools.
Many recommend using a garden hose to mark out the line a path will take, but sometimes it's a bit too flexible when organizing a nice, sweeping curve. Also in the same department as the four inch pipe are long coils of flexible plastic pipe used as supply lines in household wells. Cut to varying lengths, these are helpful in marking path lines because they are sufficiently rigid to require simple anchors at key intervals (a lightweight stake) but flexible enough present a smooth curve that identifies the path edge. A second piece defines the opposite side and permits the landscaper to "field test" the path before work commences.
A common and regretted error is to predicate path design on an initial and often small garden that does not occupy all the available space. Two shortcomings often occur: a) paths on the exterior margins have a tendency to be straight lines and b) the garden is expanded by "add-on" beds that create many pathways, especially those that intersect at regular intervals. Culprits here are often service paths, which wriggle discreetly through beds for maintenance, rather than visitor, traffic purposes, punctuating with regularity the broader strolling path. It's very easy to begin to create grids of pathways, fine for botanical or formal design purposes, but unhelpful for natural gardens.
The counsel, then, would be to consider the long term, even if the expectations appear unrealistic. Confessing to grand schemes can result in sneers and snickers, so it's sometimes best to keep the master plan tucked into a private agenda and tolerate questions coming from ignorance of them. In the meantime, if a path ends abruptly, it can finish in a cul-de-sac or temporary garden room that can be easily modified when funds and ambition grow.