Plant spacing is one of the most important design and horticultural decisions in landscape planning. Proper spacing affects plant health, aesthetics, maintenance cost, and the long-term success of your landscape. Plants spaced too close compete for light, nutrients, and water and may quickly become overcrowded. Conversely, plants spaced too far apart create gaps, invite weed invasion, and underuse the available space.
Landscape Plant Spacing Calculator
This comprehensive guide covers:
- Why proper plant spacing is critical
- How to determine the right spacing based on plant size and purpose
- Spacing recommendations for trees, shrubs, hedges, and groundcovers
- Special considerations for urban landscapes and habitat restoration
- How to calculate the number of plants needed for your area
- Practical tips and common mistakes
- Five detailed tables summarizing spacing guidance
Why Is Landscape Plant Spacing Important?
Plant spacing is a balance between maximizing landscape aesthetics, supporting plant health, and controlling long-term maintenance. Here’s why it matters:
- Healthy growth and development: Plants grown too close compete, stressing roots and foliage, reducing vigor.
- Disease and pest control: Good airflow from proper spacing reduces disease risk caused by humidity and shading.
- Visual appeal: Proper spacing integrates mature plant size, creating harmonious, natural-looking landscapes.
- Maintenance: Closer planting may increase pruning and disease management, while wider spacing may increase weeding and irrigation efforts.
- Cost efficiency: Space used wisely minimizes waste and planting costs.
General Principles for Determining Plant Spacing
The ultimate mature size of a plant is the best guide to how far apart to plant. This “mature spread” or “canopy width” is the critical dimension plants will occupy at adulthood.
Rule of Thumb:
Space plants apart by roughly their mature width (in feet or meters).
If planting two species side-by-side, spacing equals half the mature spread radius of each added together. For example, if Plant A grows 8 ft wide and Plant B grows 6 ft wide, space them about 7 ft apart (half of 8 plus half of 6).
Also consider the following:
- Pruning and training methods can reduce canopy size and allow closer spacing.
- Desired landscape effect influences spacing: tight for instant privacy hedges; wider for specimen displays.
- Budget and maintenance capacity affect plant quantity and spacing choices.
Types of Plants and Their Recommended Spacing
1. Trees
Trees require the most space, based on mature canopy diameter.
| Tree Size | Expected Mature Width | Recommended Minimum Spacing from Structures | Spacing Between Trees (ft/m) |
|---|---|---|---|
| Small Trees (<20 ft) | 10–20 ft (3–6 m) | 2 ft (0.6 m) from foundations | 10–15 ft (3–5 m) |
| Medium Trees (20–40 ft) | 20–40 ft (6–12 m) | 3–5 ft (1–1.5 m) from foundations | 20–40 ft (6–12 m) |
| Large Trees (>40 ft) | 40+ ft (12+ m) | 4–5 ft (1.2–1.5 m) from foundations | 30–50+ ft (9–15+ m) |
Example: A 40 ft wide maple planted 40 ft from the next tree or structure provides room for full growth without crowding (ISA Arboriculture).
2. Shrubs
Shrubs fill mid-level landscape space. Spacing depends on final size and use (hedging, specimen, mass planting).
| Shrub Size | Mature Width | Recommended Minimum Spacing (ft/m) | Recommended Distance from House/Foundation (ft/m) |
|---|---|---|---|
| Small Shrubs (<3 ft) | 2–3 ft (0.6–0.9 m) | 2–3 ft (0.6–0.9 m) | 2 ft (0.6 m) |
| Medium Shrubs (3–6 ft) | 4–6 ft (1.2–1.8 m) | 3–4 ft (0.9–1.2 m) | 3 ft (1 m) |
| Tall Shrubs (6–10 ft) | 6–10 ft (1.8–3 m) | 4–6 ft (1.2–1.8 m) | 4–5 ft (1.2–1.5 m) |
Tip: Shrubs should be spaced enough so foliage doesn’t overcrowd but dense enough for visual impact and privacy (WSU Extension).
3. Hedges
Hedges require closer spacing to form a continuous screen.
| Hedge Type | Recommended Spacing (inches/cm) | Typical Height (ft/m) | Use Case |
|---|---|---|---|
| Low Hedge | 12–18 in (30–45 cm) | 2–4 ft (0.6–1.2 m) | Border flower beds, small privacy |
| Medium Hedge | 18–24 in (45–60 cm) | 4–6 ft (1.2–1.8 m) | Privacy, windbreaks |
| Tall Hedge | 24–36 in (60–90 cm) | 6–10 ft (1.8–3 m) | Privacy screens, noise barriers |
4. Groundcovers
Spacing for groundcovers depends primarily on desired growth speed and coverage density.
| Spacing Between Plants | Area Covered (48 plants) | Area Covered (100 plants) | Typical Groundcover Types |
|---|---|---|---|
| 6 in (15 cm) | 10 sq ft | 21.5 sq ft | Fast-spreading low runners |
| 12 in (30 cm) | 41.5 sq ft | 86.5 sq ft | Clumping types like sedum or pachysandra |
| 18 in (45 cm) | 92 sq ft | 192 sq ft | Larger runners or spreading shrubs |
(Source: Sunset Magazine, Spacing Groundcover Plants)
Table 1: Summary of Landscape Plant Spacing Guidelines
| Plant Type | Mature Size (ft) | Suggested Spacing (ft) | Typical Use |
|---|---|---|---|
| Small tree | 10–20 | 10–15 | Shade, specimen |
| Medium tree | 20–40 | 20–40 | Shade, avenue planting |
| Large tree | >40 | 30–50 | Large shade tree, park tree |
| Small shrub | <3 | 2–3 | Ground-level accents |
| Medium shrub | 3–6 | 3–4 | Borders, mixed beds |
| Tall shrub | 6–10 | 4–6 | Privacy hedges |
| Low Hedge | <4 | 1–1.5 | Decorative borders |
| Medium Hedge | 4–6 | 1.5–2 | Privacy, windbreak |
| Tall Hedge | >6 | 2–3 | Screening, sound barrier |
| Groundcover | Variable | 0.5–1.5 (feet) | Soil coverage, weed suppression |
Calculating the Number of Plants Needed for Your Landscape
To calculate plant numbers, measure your planting area, and divide by plant spacing squared (for square planting). Adjust for triangular or staggered arrangements for higher density.
Plant Number Formula:
Number of Plants=Area(Spacing)2Number of Plants=(Spacing)2Area
Where:
- Area is in square feet or meters
- Spacing is the distance between plants (in the same units as Area)
Example for a Shrub Border
- Length: 50 ft, Row width: 4 ft
- Area = 50 x 4 = 200 sq ft
- Spacing: 3 ft (for medium shrub)
Plants=20032=2009≈22Plants=32200=9200≈22
Table 2: Plant Count per 100 Square Feet by Spacing
| Spacing (ft) | Plants per 100 sq ft (Square Layout) | Plants per 100 sq ft (Triangular Layout) |
|---|---|---|
| 1 | 100 | 115 |
| 2 | 25 | 29 |
| 3 | 11 | 13 |
| 4 | 6 | 7 |
| 5 | 4 | 5 |
Triangular layout increases density by ~15% compared to square.
Special Considerations for Urban Landscaping and Habitat Restoration
Urban Landscaping
- Maintain safe distances from sidewalks, utilities, and structures to avoid root and canopy conflicts (ISA Arboriculture).
- Use smaller plant species or cultivars where space is limited.
- Incorporate multi-layered plantings with groundcovers, shrubs, and trees spaced appropriately for full growth.
Habitat Restoration / Naturalistic Plantings
- Plants spaced closer (1–3 ft for groundcovers, 5–10 ft for shrubs, 10–15 ft for trees) to encourage robust natural growth and fast weed competition (King County Native Plant Guide).
- Denser planting reduces maintenance but initially costs more and creates a more “wild” appearance.
Table 3: Plant Spacing and Coverage Time
| Plant Spacing (inches) | Approximate Time to Full Coverage | Notes |
|---|---|---|
| 6 | 12–18 months | Fast coverage; higher initial cost |
| 12 | 24–36 months | Moderate speed; balanced cost |
| 18 | 3+ years | Slower coverage; lower initial cost |
Tips for Successful Plant Spacing and Layout
- Use stakes and strings or a garden grid to maintain uniform spacing during planting.
- Consider mature plant size and shape before finalizing spacing.
- Allow space for pruning and maintenance.
- Select staggered/triangular planting for dense coverage.
- Adjust spacing based on microclimate and soil fertility.
Common Mistakes and How to Avoid Them
| Mistake | Consequence | Solution |
|---|---|---|
| Planting too close | Overcrowding, poor airflow, disease | Follow mature size spacing, thin early |
| Planting too far apart | Gaps, weed growth, underutilized space | Use spacing formulas to calculate correctly |
| Ignoring mature plant size | Damage to structures, poor aesthetics | Research and plan according to specific species |
| Overlooking maintenance needs | Difficult pruning, pest control | Leave access space per garden plan |
Table 4: Recommended Plant Spacing for Common Landscape Plants
| Common Landscape Plant | Mature Width (ft) | Recommended Spacing (ft) | Typical Use |
|---|---|---|---|
| Boxwood (Buxus) | 3–5 | 2–4 | Low formal hedge |
| Holly (Ilex) | 5–8 | 4–6 | Privacy hedge |
| Red Maple (Acer rubrum) | 30–50 | 30+ | Shade tree |
| Azalea | 3–4 | 3 | Accent shrub |
| Juniper | 5–10 | 4–8 | Ground cover/shrub |
Table 5: Plant Spacing for Different Landscaping Goals
| Goal | Plant Type | Recommended Spacing | Notes |
|---|---|---|---|
| Privacy Screen | Tall trees/shrubs | 3–6 ft (shrubs), 20–30 ft (trees) | Even spacing for dense effect |
| Formal Hedge | Shrubs | 12–24 in | Clipped, uniform appearance |
| Ground Cover | Low plants | 6–18 in | Depends on speed desired |
| Natural Habitat | Mixed species | Variable, denser for natives | Promote diversity, ecology |
| Ornamental Specimen | Trees, large shrubs | At least mature width | Showcase individual plants |
Final Thoughts
Proper landscape plant spacing is foundational for vibrant, healthy, and manageable gardens and green spaces. Spacing based on mature plant size, intended use, and site conditions ensures plants thrive without crowding or wasted space.
Whether you’re planting a formal boxwood hedge, a naturalistic native plant habitat, or a mixed shade garden, this guide and tables offer principles to craft effective planting plans. Remember to adjust spacing with pruning plans and maintenance in mind to keep your landscape beautiful for years.
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