Landscape & Hardscape Install & Design
Landscape & Hardscape Install & Design
This domain tests whether you can read a Minnesota site, select plants that survive Zone 3–4 winters, and detail walks, patios, and walls that survive frost. Expect plan reading, grading, base construction, and planting-depth questions.
Site and soil first
- Test soil and check drainage, compaction, and slope before drawing.
- Note winter salt and snow-storage areas, utilities, sun exposure, and mature plant size.
- Frost depth in Minnesota is commonly 42–60 in.; footings and wall bases must go below it.
- Grade surfaces 1–2% away from buildings.
Base, edges, and walls
- Excavate, place geotextile, and compact base aggregate in lifts.
- Use edge restraint and bedding course; install joint sand per manufacturer.
- Retaining walls need a leveling pad, drainage gravel, filter fabric, weep holes, and geogrid where designed. Backfill and compact in lifts.
Planting
- Set the root flare at grade; dig the hole 2–3× the rootball width.
- Mulch 2–3 in. deep, pulled back from the trunk; water to settle.
- Stake only when necessary and remove ties after one to two seasons.
Worked example
A 12×16 ft patio with a 6-in. compacted base: area = 192 ft². Volume = 192 × 0.5 ft = 96 ft³. Divide by 27 = 3.56 yd³. Add 20% for compaction: 3.56 × 1.2 = 4.27 yd³, so order about 4.5 yd³. A 1.5% slope across 12 ft drops 0.18 ft, or about 2.2 in. Set the far edge down 2.2 in. from the building edge.
Traps that cost marks
- Designing a flat patio against the house.
- Specifying a base that is too thin or not compacted in lifts.
- Planting too deep or burying the root flare.
- Forgetting edge restraint, which lets pavers spread.
- Choosing a plant for its nursery size, not its mature size.