Best Plants for Growing on Former Landfill Areas

Repurposing former landfill sites into green, productive spaces is an increasingly popular approach to land rehabilitation and sustainable urban development. However, transforming these areas presents unique challenges due to soil contamination, poor nutrient availability, compacted substrates, and sometimes unstable ground conditions. Selecting the right plants that can tolerate adverse conditions and contribute positively to soil recovery is crucial for successful landfill reclamation.

In this article, we explore the best plants for growing on former landfill areas , species that are resilient, capable of improving soil quality, and can thrive in the challenging environment typical of reclaimed landfills.

Challenges of Growing Plants on Former Landfill Sites

Before discussing plant choices, it’s important to understand the main challenges associated with growing vegetation on landfill sites:

Soil Contamination: Landfills often contain hazardous chemicals or heavy metals that leach into the soil.
Poor Soil Quality: The soil substrate is usually a mix of decomposed materials with low organic matter and poor structure.
Compaction: Heavy machinery used during landfill operations results in compacted ground with low aeration.
Drainage Issues: Variable drainage can cause waterlogging or drought-like conditions.
Unstable Ground: Settling and shifting waste beneath the surface cause instability.
Nutrient Deficiency: Nutrient levels are typically insufficient for most conventional plants.

Due to these conditions, only hardy plants that can tolerate stress and improve the ecosystem are suitable for planting.

Criteria for Selecting Plants for Landfill Reclamation

When selecting plants for former landfill sites, consider species that:

Are tolerant of poor, compacted soils.
Can withstand potential chemical contaminants.
Have deep or extensive root systems to stabilize the soil.
Contribute organic matter to improve soil fertility.
Are fast-growing to provide quick vegetation cover and prevent erosion.
Support biodiversity and native wildlife where possible.

With these criteria in mind, we will look at some of the best plants that meet these needs.

Grasses: The Pioneer Vegetation

Grasses are often the first choice for landfill reclamation because they establish quickly and create a protective ground cover. Their fibrous roots help bind soil particles and reduce erosion.

1. Switchgrass (Panicum virgatum)

Switchgrass is a native warm-season grass known for its drought tolerance and adaptability to poor soils. It thrives in sandy, gravelly, or compacted soil types commonly found on landfill sites.

Benefits:
– Deep root system improves soil structure.
– Provides biomass that enhances organic matter content.
– Can tolerate moderate contamination levels.

2. Tall Fescue (Festuca arundinacea)

Tall fescue is a cool-season grass well-suited to degraded soils. It has good tolerance to drought and compaction and establishes dense sod that controls erosion.

Benefits:
– Tolerates a wide range of pH and nutrient levels.
– Supports soil microbe diversity.
– Durable under foot traffic and harsh weather.

3. Reed Canary Grass (Phalaris arundinacea)

This robust perennial grass is ideal for wetter landfill areas prone to waterlogging. It grows rapidly and forms dense stands.

Benefits:
– Controls erosion on slopes.
– Thrives in poor-quality wet soils.
– Can bioaccumulate some heavy metals (phytoremediation potential).

Legumes: Natural Nitrogen Fixers

Leguminous plants fix atmospheric nitrogen through symbiosis with rhizobia bacteria, enriching soil fertility naturally , a significant advantage on nutrient-depleted landfill soils.

4. Bird’s-foot Trefoil (Lotus corniculatus)

Bird’s-foot trefoil is a hardy legume that grows well in poor soils with low pH and compaction. It provides good ground cover and forage value.

Benefits:
– Fixes nitrogen improving soil fertility.
– Drought tolerant once established.
– Attracts pollinators enhancing biodiversity.

5. Red Clover (Trifolium pratense)

Red clover is a widely used forage legume that establishes quickly on disturbed sites. It improves soil structure through its root system.

Benefits:
– Increases nitrogen content in soil.
– Provides nectar for pollinators.
– Grows well in various climates.

Shrubs: Stabilizing Soil and Creating Habitat

Shrubs provide structural diversity in reclaimed landfills, help stabilize slopes with their woody root systems, and offer habitat for wildlife.

6. Willow (Salix spp.)

Willows are pioneer shrubs/trees known for their rapid growth and extensive root networks. They are excellent for stabilizing soils along waterways or slopes on reclaimed landfills.

Benefits:
– Tolerates wet or poorly drained conditions.
– Phytoremediates certain contaminants like heavy metals.
– Provides shade and wildlife habitat.

7. Red Osier Dogwood (Cornus sericea)

This native shrub thrives in wet or disturbed soils typical of landfill margins or depressions. Its dense growth offers excellent erosion control.

Benefits:
– Tolerant of poor soils.
– Supports birds and pollinators.
– Adds organic matter through leaf litter.

8. Hazel (Corylus avellana)

Hazel is a hardy shrub adaptable to different soil types, including those found on reclaimed sites. Its roots help bind the soil effectively.

Benefits:
– Tolerates varying moisture levels.
– Produces nuts supporting wildlife food webs.
– Responds well to coppicing aiding management practices.

Trees: Long-Term Soil Improvement and Carbon Sequestration

Trees planted on former landfills contribute to long-term site stabilization, carbon capture, and creation of microclimates facilitating succession of other species over time.

9. Silver Maple (Acer saccharinum)

Silver maple tolerates wet soils often encountered at landfill sites due to poor drainage or settling waste layers. Its rapid growth is beneficial for quick canopy establishment.

Benefits:
– Adaptable to variable moisture and nutrient conditions.
– Improves air quality by sequestering pollutants.
– Provides shade reducing temperature extremes affecting soil microbes.

10. Black Locust (Robinia pseudoacacia)

Black locust is a nitrogen-fixing tree known for thriving in degraded lands with poor nutrient availability. It has pest resistance and fast growth characteristics.

Benefits:
– Enriches soil nitrogen naturally.
– Deep roots stabilize soil layers effectively.
– Produces durable hard wood useful economically if harvested sustainably.

11. Eastern Cottonwood (Populus deltoides)

Eastern cottonwood grows rapidly on moist sites common near landfill edges or depressions where water accumulates.

Benefits:
– Effective at phytoremediation by absorbing pollutants from soil and water.
– Establishes quickly providing windbreaks or shade.

Herbaceous Perennials: Enhancing Biodiversity

Herbaceous perennials add flowering diversity that supports pollinators while also tolerating tough site conditions when appropriately selected.

12. Purple Coneflower (Echinacea purpurea)

A native wildflower adapted to dry, poor soils with excellent drought tolerance once established.

Benefits:
– Attracts bees, butterflies, and other pollinators increasing site biodiversity.
– Helps create aesthetically pleasing landscapes aiding public acceptance of reclaimed sites.

13. Milkweed (Asclepias spp.)

Milkweed species tolerate disturbed soils well and are critical for monarch butterfly lifecycle support.

Benefits:
– Supports declining monarch populations by providing larval host plants.
– Adapted to dry soils common on raised landfill covers.

Phytoremediation Plants: Cleaning Contaminated Sites

Certain plants have ability to uptake contaminants from soils , an important function where residual pollution remains after capping or remediation efforts.

14. Sunflower (Helianthus annuus)

Sunflowers can accumulate heavy metals like lead, zinc, cadmium making them valuable in phytoremediation efforts during early site restoration phases.

Benefits:
– Rapid biomass production extracts pollutants efficiently.
– Seeds can be harvested post-remediation preventing entry into food chains unintentionally.

15. Indian Mustard (Brassica juncea)

Another effective phytoremediator of heavy metals; Indian mustard grows fast on marginal lands requiring minimal inputs.

Benefits:
– Enhances removal of toxic elements from contaminated soils.

Best Practices for Planting on Former Landfills

Choosing appropriate plants is only part of successful landfill reclamation; proper site preparation and ongoing management are crucial:

Soil Testing: Conduct thorough testing to assess contamination levels, pH, nutrients , tailor amendments accordingly.
Use Cap Layers: Apply engineered caps like clay or geotextiles before planting to isolate contaminants safely from plant roots if necessary.
Improve Soil Quality: Incorporate organic matter such as compost or biochar to improve texture and fertility where feasible.
Erosion Control Measures: Use mulch, erosion mats, or temporary cover crops during initial establishment period to prevent washout of seeds/soil particles.
Phased Planting: Begin with pioneer species like grasses/legumes followed by shrubs/trees after site stabilization progresses.
Regular Monitoring: Track plant health, pollutant levels in biomass/soil regularly adjusting management practices as needed.
Biodiversity Focus: Incorporate native species wherever possible to restore local ecosystems effectively while providing wildlife habitat benefits.

Conclusion

Reclaiming former landfill areas through vegetation not only improves environmental health but also creates valuable green spaces that benefit local communities socially and ecologically. Selecting the best plants involves understanding site-specific limitations while choosing species capable of thriving under stress , grasses like switchgrass; nitrogen-fixing legumes such as red clover; resilient shrubs like willows; fast-growing trees including black locust; flowering perennials like purple coneflower; plus specialized phytoremediators such as sunflowers all play crucial roles in transforming these challenging environments into sustainable landscapes.

With thoughtful planning combining proper plant selection with sound reclamation techniques, former landfills can be successfully converted into thriving ecosystems contributing positively towards urban greening goals and environmental restoration efforts worldwide.