Mercer Island WA Landscape Design

MTS Tree and Landscape designs and installs residential landscapes on Mercer Island, from front-yard redesigns and planting plans to patios, drainage, irrigation, lighting, retaining features, and full-property renovations.

We start with the property itself. Slope, drainage, mature trees, shade, access, views, and City requirements all affect what should be designed before plants and materials are selected.

We've served the Eastside and Seattle since 2005. Our landscape designers have years of Pacific Northwest experience, and our installation crews can carry the approved design through hardscape, planting, irrigation, drainage, and lighting.

Call (425) 369-8733 or request a landscape consultation.

What Can We Design and Build for Your Mercer Island Property?

We provide landscape design and installation for projects ranging from focused front-yard improvements to complete residential renovations.

Your project can include:

• Front- and backyard redesign
• Planting plans
• Patios and outdoor living areas
• Walkways and entries
• Retaining walls and terracing
• Grading and drainage
• Irrigation
• Landscape lighting
• Lawn or turf areas
• Privacy planting
• Native and regionally adapted planting
• Tree integration
• View-oriented planting
• Hardscape construction
• Full landscape installation

The plan should answer three things before installation starts: how the property will be used, how the site conditions affect the design, and how all of the pieces will work together.

For related services, see our tree, landscape, and hardscape services on Mercer Island.

How Does Our Landscape Design Process Work?

Our current landscape-design process generally moves from site analysis to concept, detailed scope, and installation.

1. On-Site Consultation and Measurement

We walk the property with you and discuss what is not working now and what you want the finished landscape to do differently.

We also assess:

• Slope and grade
• Drainage
• Sun and shade
• Existing trees and root zones
• Structures and utilities
• Access
• Existing irrigation
• Views and privacy
• Features worth keeping

2. Concept and Material Direction

We establish the major layout before choosing every individual plant.

That can include patio location, circulation, planting areas, drainage strategy, retaining features, privacy, views, and the relationship between the landscape and house.

We then develop the plant palette and material selections around that layout.

3. Detailed Plan and Project Budget

Our published design process includes a detailed plan with quantities, specifications, and budget.

For many projects, MTS currently allows approximately 1 to 3 weeks for the design phase.

4. Installation

Once the scope is approved, our crews can coordinate hardscape, planting, irrigation, drainage, and lighting rather than handing the plan to an unrelated installer.

Our published installation timeframe is typically 1 to 6 weeks depending on project scope. Permits, engineering, material lead times, site restrictions, or unusually large projects can extend the overall schedule.

See our broader landscape design and installation services.

Landscape Design for Sloped, Wooded, and Waterfront Properties

Mercer Island landscape design often has to solve grade, drainage, mature trees, shade, and regulated site conditions before aesthetics can be finalized.

Site condition	Design priority
Steep or uneven grade	Safe circulation, usable space, drainage, and appropriate grade transitions
Mature tree canopy	Root protection, excavation limits, shade, and compatible planting
Poor drainage	Grading, runoff direction, drainage infrastructure, and permeable surfaces
Waterfront location	Shoreline review, views, vegetation, drainage, and access
Narrow or difficult access	Material delivery, equipment, staging, and construction sequence
Heavy shade	Planting that can perform beneath the existing canopy

Design the Drainage Before the Finishes

On a sloped property, drainage affects almost everything else.

Patio elevations, walls, lawn, planting beds, walkways, and downspout discharge should be considered as part of the same site.

Mercer Island also encourages Low Impact Development approaches where feasible, including reduced impervious surfaces, retained vegetation, amended soils, bioretention, and permeable paving.

See the City's Low Impact Development guidance for current examples.

Retaining Walls and Terracing

A steep property does not automatically need one large wall.

Depending on the site, the better layout may use smaller terraces, planted grade changes, steps, walls, or a combination.

Mercer Island's building guidance says a retaining wall can qualify for a building-permit exemption when it is no more than four feet from the bottom of the footing to the top of the wall and meets the City's other exemption conditions, including surcharge, property location, and critical-area requirements.

Review the City's retaining-wall and building-permit guidance before assuming a wall is exempt.

Waterfront and Critical-Area Properties

Waterfront landscaping can involve land-use review in addition to landscape design.

Mercer Island says shoreline permitting can apply to work within 200 feet of the ordinary high water mark of Lake Washington. Critical-area review may apply to wetlands, watercourses, erosion hazards, steep slopes, potential-slide areas, and other mapped conditions.

The City also notes that geohazard review is common on Mercer Island residential projects.

See the City's residential project and critical-area guidance.

Where shoreline stabilization, engineered walls, geotechnical work, mitigation plans, or other regulated professional services are required, those scopes may need additional qualified professionals and City approval.

Front Yards, Backyards, and Outdoor Living

A good outdoor space should connect the house, landscape, circulation, planting, and hardscape rather than treat each element as a separate project.

We can design and build combinations of:

• Paver or natural-stone patios
• Walkways and entry paths
• Seat walls
• Pergolas and garden structures
• Fire features
• Outdoor kitchen areas
• Planting beds
• Privacy planting
• Low-voltage landscape lighting
• Path and step lighting
• Irrigation
• Drainage

For structural landscape features, see our hardscaping services.

Front-Yard Redesign

A front-yard plan should make the route to the house clear and organize the planting around the architecture rather than simply fill empty beds.

We look at:

• Entry walks
• Plant scale
• Existing trees
• Privacy
• Lighting
• Lawn areas
• Drainage
• Views from the street and house

A useful redesign may be as focused as planting and an improved entry walk or as broad as a complete front-yard rebuild with irrigation, lighting, grading, and hardscape.

Designing Around Lake or Territorial Views

A landscape can frame a view without stripping the property of planting.

Lower planting can preserve important sightlines, while taller screening can be placed where privacy matters.

Where an existing tree affects the view, selective pruning may be a better solution than designing the entire landscape around its removal.

Native and Lower-Maintenance Planting

Lower-maintenance landscaping begins with matching plants to the actual site.

Native plants can be excellent choices, but native does not automatically mean maintenance-free or appropriate for every location.

For example, King County identifies sword fern, salal, low Oregon grape, and vine maple among native plants that can work in shaded conditions.

Depending on the property, we may also consider plants such as:

• Red-flowering currant
• Kinnikinnick
• Evergreen huckleberry
• Snowberry
• Other Pacific Northwest natives and adapted ornamentals

The final plant palette should account for light, moisture, mature size, appearance, irrigation, and the maintenance level you want.

See King County's Native Plant Guide for examples of native plants suited to shaded Pacific Northwest sites.

Lower maintenance can also come from:

• Reducing lawn where it adds little value
• Grouping plants with similar water needs
• Using realistic mature spacing
• Installing efficient irrigation
• Mulching exposed soil
• Choosing plants that fit their available space
• Keeping maintenance access in the design

Landscape Design for New Construction and Major Renovations

Landscape decisions are easier to coordinate before the rest of a major construction project is finished.

For new homes, additions, and major renovations, early landscape planning can help resolve:

• Tree retention
• Finished grades
• Drainage
• Patio and walkway elevations
• Retaining features
• Irrigation sleeves
• Landscape-lighting infrastructure
• Construction access
• Planting areas
• Final installation sequence

Mercer Island's current residential-project requirements can involve stormwater plans, tree plans, geotechnical reports, critical-area studies, and arborist reports depending on the site and project.

We coordinate our landscape scope with the builder, architect, arborist, engineer, geotechnical consultant, or other project professionals when those disciplines are required.

Do You Need a Permit or Landscape Architect for Landscaping on Mercer Island?

A Mercer Island landscape project does not automatically require a permit, but the specific work can trigger one. Retaining walls, grading, drainage, critical areas, shoreline work, regulated tree activity, and other construction should be checked before installation.

Important current Mercer Island triggers include:

• Most work affecting ground or vegetation in a critical area requires permit review
• Shoreline permitting can apply within 200 feet of Lake Washington's ordinary high water mark
• Retaining-wall exemptions apply only when all City conditions are satisfied
• Clearing, grading, filling, or foundation work between October 1 and April 1 on certain geohazard sites can require a Seasonal Development Limitation Waiver
• Projects that alter stormwater drainage can trigger separate review

The City's stormwater permit information and shoreline guidance are useful starting points.

Do You Need a Landscape Architect?

Most residential landscape-design projects do not automatically require a licensed landscape architect.

However, Washington regulates the practice and title of landscape architecture. A project that requires stamped landscape-architecture documents or another regulated professional scope should use a properly licensed professional.

MTS Tree and Landscape provides residential landscape design and installation. We do not present ourselves as a landscape-architecture firm.

How Much Does Landscape Design and Installation Cost on Mercer Island?

A practical MTS planning range is about $8,000 to $25,000 for a full front-yard redesign, $10,000 to $50,000 for a backyard renovation, and $25,000 to $80,000 or more for a full-property design-build. Estate-scale landscape installations can reach $80,000 to $250,000 or more.

Our current King County planning ranges are:

Project scope	Current MTS regional planning range
Front-yard refresh	$2,500-$8,000
Full front-yard redesign	$8,000-$25,000
Backyard renovation	$10,000-$50,000
Full-property design-build	$25,000-$80,000+
Estate-level landscape installation	$80,000-$250,000+

These are MTS regional planning ranges, not fixed Mercer Island quotes.

Mercer Island projects can move toward the upper end when the scope includes:

• Extensive hardscape
• Retaining walls
• Major grade changes
• Drainage
• Shoreline or critical-area requirements
• Difficult access
• Mature-tree protection
• Large plant material
• Irrigation and lighting
• Engineering or other professional services

What Does Landscape Design by Itself Cost?

MTS Tree and Landscape does not publish one flat design-only fee.

The design scope should be quoted separately when you want a standalone plan or when the amount of design work is materially different from the installation scope.

Tell us whether you need a planting plan, full-property concept, hardscape layout, construction coordination, or complete design-build proposal so we can quote the correct service.

Call (425) 369-8733 or request a landscape project estimate.

Why Work With MTS Tree and Landscape?

We've served the Eastside and Seattle since 2005.

Our landscape designers have years of Pacific Northwest experience designing for sloped and flat properties, and our crews can carry the project from design through hardscape, planting, irrigation, drainage, and lighting.

MTS Tree and Landscape is licensed, bonded, and insured in Washington under contractor registration SOUNDPL826DZ and UBI 603554491.

The advantage of using one design-build team is coordination.

The patio grade affects drainage. The drainage affects planting. Existing trees affect excavation. Irrigation affects plant selection. Lighting should be planned before finished surfaces are complete.

We can address those relationships as one project instead of asking separate contractors to solve them afterward.

Start Your Mercer Island Landscape Design Project

You do not need the final plant list, patio material, or drainage solution before the first meeting.

Tell us how you use the property now, what is not working, and what you want the finished landscape to do differently.

We can evaluate the site, develop the design direction, define the construction scope, and carry the approved project through installation.

Call (425) 369-8733 or request a landscape consultation.

Mercer Island Landscape Design FAQs

How much does landscape design and installation cost on Mercer Island?

Landscape design and installation on Mercer Island commonly starts around $8,000 to $25,000 for a full front yard, $10,000 to $50,000 for a backyard renovation, and $25,000 to $80,000 or more for a full-property project. Estate-scale installations can exceed $80,000 and reach $250,000 or more.

How long does a Mercer Island landscape design project take?

MTS Tree and Landscape currently allows about 1 to 3 weeks for the design phase and 1 to 6 weeks for installation, depending on scope. Permits, engineering, material lead times, critical-area review, shoreline review, and unusually large projects can extend the overall schedule.

Can a Mercer Island landscape project be completed in phases?

Yes, a Mercer Island landscape project can be designed as one master plan and installed in phases. Drainage and major hardscape are usually planned first, followed by irrigation, planting, lighting, and other finishes so later work does not require tearing out completed areas.

Do I need a permit for landscaping on Mercer Island?

Not every Mercer Island landscape project requires a permit, but retaining walls, grading, drainage, critical areas, shoreline work, regulated tree activity, and other construction can trigger City review. Permit requirements should be checked against the actual property and scope before excavation or installation begins.

Can mature trees stay in a new landscape design?

Yes, mature trees can often remain and become part of the new landscape design. The plan should account for root zones, canopy shade, excavation, construction access, irrigation, and finished grades. Mercer Island may also require arborist documentation when development affects regulated trees.

When is the best time to start a Mercer Island landscape project?

Landscape design can begin year-round. MTS's design process typically takes 1 to 3 weeks, while the best installation window depends on hardscape, planting, weather, permit timing, and site conditions. Starting design before your preferred construction season gives more time for selections and approvals.