Sector Analysis for Garden Design

What Is Sector Analysis?

Sector analysis maps the external energies that flow through your site. Unlike zones (which radiate outward from your home based on human activity), sectors are directional forces that come from outside your property: sun angles, prevailing winds, water flow, noise, views, fire risk, and wildlife corridors.

Think of your property as sitting in a field of invisible arrows. Some bring welcome energy (winter sun, gentle rain). Others bring challenges (cold north winds, summer heat, road noise). Sector analysis identifies where these arrows come from so you can design your landscape to capture the beneficial ones and deflect the harmful ones.

Why Sector Analysis Matters

Placing a greenhouse on the wrong side of your house means it might get half the winter sun it needs. Planting a windbreak in the wrong orientation means cold gusts still hammer your vegetable beds. Building a patio without understanding afternoon sun angles means you'll bake in summer.

Every garden design problem caused by sun, wind, water, or noise has the same root cause: someone didn't do their sector analysis first. Twenty minutes with a compass and a notepad can save you years of fighting your site's natural energy patterns.

The Key Sectors to Map

Solar Sector

The sun's path across your site changes dramatically between summer and winter. In the Northern Hemisphere, summer sun tracks high and arcs far to the north, while winter sun stays low and tracks through the southern sky.

What to observe:

• Where does the sun hit your site in early morning? Midday? Late afternoon?
• Which areas get full sun all day? Partial shade? Deep shade?
• How do shadows from buildings, fences, and trees change between summer and winter?
• Where does the sun strike the house in winter (passive solar opportunity)?

Map this at both solstices if possible. A spot that's in full shade in December might get eight hours of sun in June.

Wind Sector

Wind is the sector most people underestimate. A consistent prevailing wind can dry out soil, stress plants, cool your house (helpful in summer, costly in winter), and knock over tall plantings.

What to observe:

• What is the prevailing wind direction in your area? (Check local weather data.)
• Are there seasonal variations? Many regions have different dominant winds in summer versus winter.
• Where on your site is wind strongest? Look for exposed ridges, gaps between buildings, and funnel effects.
• Where is it calmest? These sheltered spots are often your best growing areas.

Water Sector

Water flows downhill. That's obvious, but the implications are easy to miss. Slopes, even gentle ones, determine where rainwater collects, where erosion happens, and where flooding is likely.

What to observe:

• Where does water enter your property during heavy rain?
• Where does it pool or exit?
• Are there natural drainage channels?
• Where is the soil wettest? Driest?
• Does your neighbor's runoff affect your site?

Additional Sectors

Depending on your location, you may need to map:

• Fire sector: In fire-prone areas, note the direction fires typically approach. This determines where you need firebreaks and low-fuel plantings.
• Noise sector: Road noise, neighbors, industrial sounds. Identify direction and intensity.
• View sector: Both good views you want to preserve and bad views you want to screen.
• Wildlife corridors: Where do deer, rabbits, or other animals enter your property?
• Frost pocket sector: Cold air flows downhill and pools in low spots. These frost pockets can be two or three hardiness zones colder than nearby hilltops.

How to Do a Sector Analysis

Step 1: Get a Base Map

Start with a bird's-eye view of your property. A printed satellite image from mapping software works well. Mark your house, outbuildings, existing trees, fences, and property boundaries.

Step 2: Mark North

Orient your map and draw a clear north arrow. All your sector observations reference compass directions.

Step 3: Draw Sector Arrows

Using your observations (and local weather data for wind), draw arrows from the edges of your map inward toward the center of your site:

• Yellow arrows for summer and winter sun arcs
• Blue arrows for prevailing wind directions (mark winter and summer separately if they differ)
• Light blue arrows for water flow direction
• Red arrows for fire risk direction (if applicable)
• Brown arrows for noise sources
• Green arrows for wildlife entry corridors

Step 4: Identify Intersections

The magic happens where sectors overlap. A spot that gets full winter sun AND is sheltered from prevailing wind is ideal for a greenhouse or early-season growing area. A slope that channels both wind and water might need a combined windbreak and swale system.

Step 5: Design Responses

For each sector, decide whether you need to:

• Capture it: Position elements to collect beneficial energy (solar panels in the sun sector, rain barrels in the water flow sector)
• Deflect it: Use barriers to redirect unwanted energy (windbreaks for cold wind, shade trees for summer heat)
• Channel it: Direct energy to where it's useful (swales to move water to dry zones)
• Do nothing: Some sectors need no intervention

Practical Design Responses

Wind Management

The most effective windbreak isn't a solid wall. A permeable windbreak (mixed hedgerow, deciduous trees, evergreen understory) slows wind over a much larger area than a solid fence, which just creates turbulence on the leeward side.

A good windbreak protects a downwind distance of roughly 10-15 times its height. A 3-meter-tall hedgerow shelters about 30-45 meters of garden behind it.

Sun Optimization

Deciduous trees on the south and west sides of a building give you both worlds: shade in summer when they're in full leaf, and solar gain in winter when they're bare. This is one of the oldest passive design strategies in the world, and it still works perfectly.

Water Capture

Understanding your water sector tells you where to place swales, rain gardens, and storage tanks. The goal is to slow water down, spread it out, and sink it into the soil before it leaves your property. Every drop of rain that runs off your site is a lost resource.

Common Mistakes

Doing sector analysis once and forgetting it. Sectors change with seasons. A summer wind analysis alone will miss the cold winter gusts that kill your tender plantings.

Ignoring neighboring properties. A neighbor's two-story building can cast a shadow across half your yard in winter. Their paved driveway might channel stormwater onto your land. Sectors don't respect property lines.

Treating all wind as bad. Summer breezes cool your house and dry out fungal diseases on plant leaves. Don't block beneficial wind while trying to stop cold winter gusts. Use deciduous windbreaks that are permeable in summer and denser in winter.

Neglecting the frost sector. Cold air is denser than warm air and flows downhill like water. A fence or hedge at the bottom of a slope can trap cold air and create a severe frost pocket. Sometimes the fix is simply leaving a gap in a barrier so cold air can drain away.

Overcomplicating the map. You don't need surveying equipment or software for a basic sector analysis. A compass, a notepad, and careful observation across two or three seasons will give you everything you need to make good design decisions.

In PatternBase, the sector analysis tool lets you map directional energy flows on your garden with a visual compass rose, so you can see how sun, wind, and water interact with your specific layout.