Garden Boardwalk: Crossing Wet or Soft Ground Without Damage
A garden boardwalk is a raised wooden walk over wet or soft ground. It gives you a dry route through low spots plus rain gardens.
The short answer
University of Wisconsin Extension notes roots need oxygen, while flooding cuts the oxygen in soil. Clay holds water longer than sand. UConn NEMO describes rain gardens as shallow dips that take roof runoff. A boardwalk lets you cross these wet spots while Iowa State native perennials fill the edges.
When does a garden need a boardwalk?
UW notes clay soil stays wet longer. A low spot that holds water after rain or a rain garden that takes runoff are the usual cases. UConn notes a home rain garden is often 50 to 100 square feet.
| Plant | Site | Source note |
|---|---|---|
| Swamp milkweed | Low moist spots | Iowa State |
| Turtlehead | Moist part shade | Iowa State |
| Joe Pye weed | Moist full sun | Iowa State |
| Rose mallow | Wet full sun | Iowa State |
| Southern blue flag | Wet full sun | Iowa State |
Source: Iowa State University Extension.
What should a boardwalk sit on?
The sources do not cover boardwalk footings. Iowa State notes wet sites can be hard but also give gardening chances. Route the walk past plants that like moist soil.
How wide should a garden boardwalk be?
No source gives a boardwalk width. Size it to the expected use plus the space between plantings.
How to: step by step
- Map the wet or soft area after rain.
- Time how long water stands.
- Plan the route around low spots.
- Set the walk on firm footing.
- Plant moisture loving natives along it.
- Check the ground after heavy rain.
Troubleshooting
Water stands for days: heavy clay. UW notes clay stays wet longer.
Plants along it decline: roots lack oxygen. Pick wet site natives.
Leaves wilt after flooding: root injury. UW notes some plants recover in a season.
Read garden microclimates, planning an outdoor garden layout plus overwatering. Kind Seed Co also stocks cannabis seeds.
Sources
- Native perennials for moist to wet soils, Iowa State University Extension, Yard and Garden
- Rain gardens, UConn CT NEMO Program
- Effects of flooding on woody landscape plants, University of Wisconsin Extension Horticulture
FAQ
Can a boardwalk go through a rain garden?
UConn NEMO notes rain gardens are shallow dips that take runoff from roofs. A raised walk lets you cross without stepping in the planted bed.
What plants grow beside a wet boardwalk?
Iowa State lists swamp milkweed, turtlehead plus Joe Pye weed for moist to wet soils. Rose mallow plus southern blue flag like wet soil in full sun.
How long can roots sit in water?
UW Extension notes most plants can take a few days of flooding in the growing season. Dormant plants take it better than plants in active growth.
How big is a home rain garden?
UConn NEMO notes a typical home rain garden is 50 to 100 square feet. Size depends on the area draining into it.
Why does soggy soil hurt roots?
UW Extension notes roots need oxygen for growth. Flooding cuts soil oxygen plus slows root respiration.
