Landscape design and build in Portland.

You are gardening on a flood, or you are gardening on a volcano

The inner east side sits on Missoula Flood deposits — silt over sand and gravel, laid down when an ice dam in Montana failed repeatedly at the end of the last ice age. It drains far better than most people expect. If your Laurelhurst bed is waterlogged, the flood deposits are almost never the reason.

The reason is usually the last hundred years. Basement spoil spread across the back garden, subsoil compacted flat by a machine, and six inches of imported bark-and-sand sold as topsoil laid over the top of it. Plants root down through the good-looking layer, hit the pan, and stop.

West of the river the ground is different in kind. Portland Hills Silt — wind-blown loess, forty feet deep in places — sitting on Columbia River Basalt. It holds a slope beautifully until it is saturated, and then it does not.

Flat, and connected to a combined sewer

Most of the east side has almost no fall to work with, and the storm drain and the sanitary sewer are frequently the same pipe. That makes keeping roof water on the property genuinely valuable rather than merely virtuous — a rain garden here is doing real work in a real system, and the city's stormwater utility discount for on-site management is worth asking about before you build one.

Deer

Effectively none east of the river. Above about five hundred feet in the West Hills it is a different conversation, and worth designing around rather than fencing after.

The lots

The standard platted lot is fifty by a hundred feet, aligned to the grid, which means most back gardens are long, narrow and either firmly north-facing or firmly south-facing. That single fact decides more about a planting plan here than budget does.

Trees are regulated, and the rules have teeth

Portland's tree code requires a permit to remove most trees above a size threshold, on private property, including in a back garden. It also protects the root zone of street trees during construction. We check this before drawing anything, because a plan that quietly assumes a tree comes out is not a plan.