Slopes and embankments are prone to soil erosion, especially when heavy rainfall causes water runoff. Strategically planting the right vegetation helps control erosion by stabilizing the soil. When selecting plants, consider their soil needs, growth rate, mature size, and root depth. This article explores top plant choices for slopes, focusing on soil-binding shrubs and pine trees.
Groundcover Junipers Offer Low-Maintenance Erosion Control
Junipers are a top choice for planting on slopes and banks. Here are some key tips:
Plant at an Angle to Match the Slope
Dig holes and plant the junipers at the same angle as the slope rather than straight down. This helps the plants establish and grow following the slope contour.
Space Plants Appropriately
Space the juniper plants between 3-6 feet apart depending on the variety. This allows adequate room for growth and ground coverage.
Prune and Weed for Optimal Growth
Prune junipers routinely to maintain shape and fullness. Also, pull weeds and clear debris to prevent excess moisture retention. Proper pruning and weeding encourage healthy growth.
Choose Low-Growing Varieties
For slopes and banks, choose low-growing juniper varieties under 3 feet tall, such as Blue Rug, Bar Harbor, or Gold Coast. Lower junipers spread readily and require less maintenance.
Be Patient!
Give junipers 2-3 years after planting to fully establish and fill in the area. Their slow growth habit means patience is required when first planting. But once established, they offer durable and attractive ground cover.
Additional Superb Plants for Erosion Control
Beyond junipers, several other plants are well-suited for planting on slopes and preventing erosion. Some top options include:
Myoporum
This fast-growing ground cover has a deep root system that penetrates compacted soil. Myoporum spreads quickly, up to 15 feet wide, and thrives in full sun and dry conditions. It helps control runoff while adding visual interest with small white flowers.
This fast-growing, flowering groundcover thrives on banks and slopes. Key features:
- Drought tolerant once established
- Hardy to 20°F
- Low maintenance; requires occasional pruning
- Provides summer blooms
Lantana
Lantana is a heat-loving spreading plant that grows quickly. Considerations when planting lantana:
- Give ample space for growth
- Can be used throughout landscape
- Establish watering routine when first planting
- Prune routinely to encourage dense foliage
Ceanothus
This hardy shrub grows 1-3 feet tall. With proper care, ceanothus develops deep roots to stabilize up to 15 cubic feet of soil. It prefers full sun and well-drained soil. Varieties like ‘Yankee Point’ spread up to 20 feet wide, providing excellent ground cover.
This low-spreading shrub stabilizes soil effectively. Tips for planting ceanothus:
- Prefers full sun or light shade
- Drought tolerant when mature
- Can bloom in winter and spring
- Requires more care when first establishing
- Prune regularly to maintain fullness
Consider Maintenance Requirements
When selecting plants for slopes, consider their mature size, growth rate, ideal conditions, and maintenance needs. Plan and prepare the area well for successful erosion control.
Soil-Stabilizing Shrubs
Several spreading shrub species thrive on slopes while preventing soil erosion. Their dense root systems and groundcover growth habit help control water runoff and retain soil.
Cotoneaster
Cotoneaster spreads outwards 6-10 feet wide, making it ideal for covering slopes. It grows well in poor, dry soils and requires little maintenance. Routine pruning encourages dense growth to reduce erosion.
Juniper
Juniper shrubs and groundcovers have extensive shallow roots that stabilize soil. Drought-tolerant varieties like ‘Blue Pacific’ grow just 1-2 feet tall but spread several feet wide. Space junipers 3-6 feet apart when planting slopes.
Potentilla
Also called cinquefoil, potentilla grows rapidly and spreads via underground stems. Varieties like ‘Red Ace’ reach just 12 inches tall but spread several feet wide. Potentilla reduces erosion on banks and slopes with its dense trailing stems and roots.
Soil-Anchoring Pine Trees
In addition to spreading shrubs, pine trees help stabilize soil on slopes with their extensive root systems. Consider these erosion-fighting pine species:
Austrian Black Pine
Capable of growing in poor, compacted soil, the Austrian black pine has aggressive roots that penetrate deep into the ground. Mature trees can develop taproots up to 13 feet deep to anchor the soil.
Lodgepole Pine
Lodgepole pines thrive in well-drained, acidic soil. Their tall height and spreading root system make them ideal for large slopes. Given sufficient space, lodgepole pines can grow over 150 feet tall at maturity.
Monterey Pine
A fast-growing pine suited to dry soils, Monterey pines produce a dense network of lateral roots close to the surface. This helps stabilize the top layers of soil vulnerable to erosion. The trees’ rapid growth also enables quick soil coverage.
Ponderosa Pine
Also called the western yellow pine, ponderosas develop deep taproots along with lateral roots extending up to 90 feet from the trunk. A mature ponderosa can have over 45,000 cubic feet of roots anchoring and reinforcing the surrounding soil.
Scotch Pine
Tolerant of a wide range of soil types, Scotch pine is an excellent choice for slopes and embankments. It develops an extensive root system and grows up to 60 feet tall at maturity to provide substantial soil anchoring.
Tips for Planting Erosion Control Vegetation
When establishing plants to prevent erosion, follow these tips:
- Test the soil to identify pH, composition, and nutrients needed
- Amend poor soils with compost or manure before planting
- Space plants appropriately based on their mature spread size
- Add 2-4 inches of organic mulch around plants to retain moisture
- Water plants regularly until their root systems fully establish
- Prune and weed around plants to encourage healthy growth
- Be patient – allow 2-3 years for plants to reach mature size and erosion control potential