Like installing snowshoes in your lawn
Also called permeable pavement, soil reinforcement grid, open
celled paving grid, and porous paving matrix. Surfaces covered with
these materials can be planted and bear weight without compressing.
The grid is made of a material with regularly interspersed voids,
where the voids are filled with permeable materials such as gravel,
sand or soil and plants. Used in parking lots and heavy foot
traffic areas in botanical gardens and public parks, for erosion
control under paths over fragile soils, for green driveways and
emergency vehicle access routes through natural areas.
Imagine slicing the tops and bottoms off of soup cans, then
slicing the cans to create two or three open cylinders from each
can. Now arrange those cylinders on the ground, side by side like a
honeycomb with cylindrical cells. Fasten the cells together. Fill
in and between all the cans with loose soil. Plant grass seed or a
foot-tolerant groundcover. Or fill with small stones and don't
plant. Walk or drive there. The mat of cut soup cans takes the
weight. The plants' growing space or the soil around tree roots
below the grid remains loose.
It is sold in rolled mats or flat modules and may be made of
concrete cells, rigid plastic cells or composites. In our area it's
a known- but non-stocked item at landscape material supplies
company. We ask, the supplier orders it in for us. Be prepared to
describe the grid, as we have here -- take our illustration with
you! -- because it's relatively new and goes by various names.
Below: We noticed the grid of permeable paving on a recently
renovated slope at Chicago Botanic Garden. (Rings visible near
Janet's foot.)
Below: That same slope at Chicago Botanic's Dwarf Conifer Garden, four
years later, grass healthy and the slope still attractively green
despite heavy foot traffic.
Below, left: The concrete grid in Missouri Botanical
Garden parking lot is gravel filled, but in sunnier, less heavily
trafficked areas the same kind of grid might be filled with soil
and seeded (below, right).
Permeable paving performance test, results, University of
Washington
Take a look at more types of paving grids
manufactured by various companies, and a video of paving grid installation.
Consider a DIY (do-it-yourself) grid of stepping stones with
ground cover between. It's in Growing
Concerns 575: Ground covers
