Landscaping On A Slope?

| Posted by: Plant Pro

Actually, a house built on a slope need not be a problem for the owner who tackles the job after carefully studying all angles. 

Part I of this story of the October issue of “Horticulture” tells how to make slopes stable.

Slope LandscapePin

In Part II of this story, Dr. Viertel discusses moving the soil, grading, and the preparations for planting.

It also offers a valuable list of plants especially suited to slopes.

Considerations Of Making Slopes

Although the cost of moving a cubic yard of soil by mechanical means is low.

It is nonetheless sensible to retain as much of the existing grade as possible rather than to work completely at cross purposes to site conditions.

It is much more economical to push soil from one place on a property to another rather than have an excess of excavated soil hauled away or bring more soil to the site.

It is best, therefore, to try to strike a balance between cut and fill.

Topsoil, which is valuable, should always be pushed to one side before progressing further so that it may be respread when the job is done.

Besides the consideration of cost, conservation is a factor here.

The ultimate cost of a slope treatment depends on immediate grading outlay and future maintenance expenditures. 

Continual annoyance and replacement of topsoil and plant materials in the future will likely follow an effort to get by with insufficient grading in the initial establishment of slopes.

Once a slope has been structurally fashioned in a basically sound manner, it may be maintained indefinitely by using plant materials. 

The only practical value of vegetation is to prevent slopes that already have interior stability from being Bullied by water. 

Plant materials are ineffective against the forces involved in the sliding or caving-in of large volumes of material.

Grass: Common Groundcover

The grass is a common ground cover for erosion control. Once established, it affords excellent protection but also requires constant maintenance. 

Of the different permanent grass species used north of the Mason Dixon line, creeping red fescue, or one of its varieties, is the best choice for bank planting. 

This species can withstand drought and abuse. A small percentage of fast germinating grass, such as rechop or perennial rye-grass, sown with it will help to give faster protection.

Woody Plants: Permanent Protection

Woody plants offer permanent protection with the advantage of low maintenance effort. 

Because slopes should be and usually are well-drained, plants that withstand dry soil conditions are, for most banks, the safest to use. 

Since it is the surface that needs protection, certain types of plants are better than others.

Evergreens And Bushy Dense Growing Plants

Evergreen and bushy, dense-growing plants have the greatest ability to soften the impact of raindrops and prevent soil grains from being splashed downhill.

Perhaps of even greater effectiveness are thicket or mat-forming plants. Plants of this type spread by suckers or root shoots or take root from trailing branches and bind a sizeable area of soil. 

It is obvious, of course, that rapid-growing species give maximum protection faster than slow-growing ones.

List Of Plants

In any list of plants, a reader may wonder why certain kinds are excluded. The list that follows is intended for the homeowner. 

Many plants equally suitable for bank protection were omitted because of the following:

  • Size 
  • Unrefined character 
  • Supposed limited horticultural interest 
  • Similarity to others listed 

In the latter case, some advantages, such as hardiness, determined the species included.

Species Starts With Letter A

  • Alpine currant (Ribes alpinum)—dry, well-drained soil; sun or part shade; 3′ feet apart; 4′ to 6′ feet
  • Alpine flowering quince (Chaenomeles japonica Alpina)—well-drained soil; sun; 2′ feet apart; 1′ to 2′ feet
  • American bittersweet (Celastrus scandens) —dry or moist soil; sun or part shade; 3′ to 5′ feet apart; orange berries, deciduous vine

Species Starts With Letter B

  • Baltic ivy (Hedera helix Baltica)—well-drained soil; shade or part shade; 1′ feet apart; 6″ inches; evergreen vine
  • Bayberry (Myrica pensylvanica)—dry, well-drained, light airy, even poor soil; sun or part shade; 3′ feet apart; 3′ to 9′ feet; grayish-white fruit
  • Bearberry (Arctostaphylos uva-ursi)—dry, well-drained, airy acid soil; sun or part shade; 1′ feet apart; 6″ inches; evergreen
  • Bearberry cotoneaster (Cotoneaster dammeri)—well-drained soil; sun or part shade; 2′ feet apart; 6″ to 12″ inches; red berries; evergreen.
  • Billiard spirea (Spiraea x billardii)-well-drained, moist soil; sun; 3′ feet apart; 4′ to 6′ feet; rose-pink flowers.
  • Black chokeberry (Aronia melanocarpa)— well-drained, moist soil, light and airy; sun or part shade; 1′ to 2′ feet apart; 2′ to 3′ feet; fall color
  • Black jet bead (Rhodotypos tetrapetala)— dry, well-drained soil; shade or part shade; 3′ feet apart; 4′ to 5′ feet; shiny black fruit
  • Blue Ridge St. Johnswort (Hypericum buckleyi)—dry, well-drained, light soil; sun or part shade; 2′ feet apart; 6″ to 10″ inches
  • Bush cinquefoil (Potentilla fruticosa)— dry or moist soil; sun or part shade; 2′ feet apart; 3′ to 4′ feet

Species Starts With Letter C

  • Paxistima canbyi (Paxistima canbyi)— well-drained, light, acid soil; sun or part shade; 1′ feet apart; 1′ feet; evergreen
  • Catawba rhododendron (Rhododendron catawbiense)—moist, well-drained, acid soil; part shade; 4′ feet apart; 6′ feet; lilac flowers; evergreen
  • Chinese wolfberry (Lycium chinense)— dry, well-drained, even poor soil; sun or part shade; 4′ to 5′ feet apart; 5′ feet; orange-red fruit
  • Common periwinkle (Vinca minor)—moist, well-drained soil; shade or part shade; 6″ 12″ inches apart; 6″ inches evergreen; lilac-blue flowers
  • Cranberry cotoneaster (Cotoneaster apicidata)—well-drained soil; sun or part shade; 2 1/2′ feet apart; 2′ to 3′ feet; red fruit; fall color
  • Creeping mahonia (Allahonia repens)— dry, well-drained soil; shade or part shade; 2′ feet apart; 1′ feet; dark blue berries
  • Creeping juniper (Juniperus horizontalis) —dry or moist soil; sun; 2′ feet apart; 1′ feet; fall color; evergreen

Species Starts With Letter D

  • Dryland blueberry (Vaccinium: pallidum) —dry, well-drained acid soil; sun or part shade; 21/2′ feet apart; 3′ feet; scarlet foliage in fall
  • Dwarf bush-honeysuckle (Diervilla lonicera)—dry, well-drained soil; sun or part shade; 2′ feet apart; 2′ to 3′ feet
  • Dyer’s greenweed (Genista tinctoria)—light, airy, dry soil, sun; 2′ feet apart; 3′ feet

Species Starts With Letter F

  • Five-leaved aralia (Acanthopanax sieboldianus)—dry or moist soil, shade or part shade; 3′ to 4′ feet apart; 5′ to 10′ feet
  • Fragrant sumac (Rhus aromatica)—dry, well-drained, even poor soil, sun or shade; 3′ feet apart; 2 to 6; red fruit; fall color

Species Starts With Letter G

  • Gray dogwood (Comas raccinosa)—dry or moist soil; sun or part shade; 3′ feet apart; 4′ to 5′ feet; fall color

Species Starts With Letter H

  • Halls honeysuckle (Lorricera japonica Hallinan)—dry or moist soil; sun or shade; 3′ feet apart; fragrant flowers; evergreen vine in warm climates

Species Starts With Letter I

  • Indian currant or coral-berry (Symphoricarpos orbiculatus)—dry, well-drained, even poor soil; sun or part shade; 3′ feet apart; 2′ to 4′; purplish red fruit

Species Starts With Letter J

  • Japanese barberry (Berberis thunbergii)— dry, well-drained, even poor soil; sun or part shade; 3′ feet apart; 4′ to 6′ feet; fall color
  • Japanese spurge (Pachysandra terminalis) —well-drained soil; part shade; 6″ inches apart; 6″ inches; evergreen

Species Starts With Letter K

  • Kirilow indigo (Indigofera kirilowii)—well-drained soil; sun; 2 1/2′ feet apart; 3′ feet

Species Starts with Letter L

  • Laland Firethorn (Pyracantha coccinca lalandi)—dry, well-drained soil; sun or part shade; 3′ feet apart; 5′ to 10′ feet; evergreen; orange-red fruit
  • Lead-plant (Amorpha canescens)—dry, well-drained, light airy, even poor soil; sun; 2 1/2′ feet apart; 2′ to 4′ feet
  • Lowbush blueberry (Vaccinium angustifolium)—dry, well-drained, acid soil; sun or part shade; 2′ feet apart; 2’ feet

Species Starts With Letter M

  • Memorial rose (Rosa wichuraiana)—well-drained soil; sun; 4′ feet apart; 2″ to 12″ inches; white flowers
  • Mugo pine (Pinus mugo mughus)—well-drained soil; sun or part shade; 4′ to 5′ feet apart; 5′ to 10′ feet; evergreen

Species Starts With Letter O

  • Oldfield common juniper (Juniperus communis depressa)—dry, well-drained soil; sun; 3′ to 4′ feet apart; 3′ to 4′ feet; evergreen

Species Starts With Letter P

  • Prairie rose (Rosa setigera)—moist, well-drained soil; sun; 3′ feet apart; 4 to 5; rose flowers; fall color.
  • Pfitzer juniper (Juniperus chinensis ‘Pfitzeriana’)—well-drained soil; sun; 4′ to 6′ feet apart; 3 to 5; evergreen
  • Porcelain ampelopsis (Ampelopsis brevipedunculata)—dry or moist soil; sun or part shade; 3′ to 4′ feet; porcelain blue fruit; deciduous vine
  • Privet honeysuckle (Ligustrum pileata)— dry or moist soil; sun or part shade; 2 1/2′ apart; 1′ to 3′ feet; evergreen; translucent purple fruit
  • Purple broom (Cytisus purpureus)—dry, light, airy, even poor soil; sun; 2′ feet apart; 1 1/2-2′ feet
  • Purple-leaf winter-creeper (Euonymus fortunei ‘Coloratus’ )—well-drained soil; sun or part shade; 2′ feet apart; 6″ to 12″ inches; fall color; evergreen

Species Starts With Letter R

  • Red-osier dogwood (Comas stolonifera)— moist, well-drained soil; sun or part shade; 3′ to 4′ feet apart; 3′ to 5′ feet
  • Ilegel privet (Ligustrum obtusifolium ragelianton)—well-drained soil; sun or part shade; 3′ to 4′ feet apart; 4′ to 6′ feet; fall color
  • Rose-shell azalea (Rhododendron rose urn) —for well-drained, acid soil; sun or part shade; 3′ feet apart; 4′ to 6′ feet; pink flowers.

Species Starts With Letter S

  • Sargent juniper (Juniperus chinensis var. sargentii)—well-drained soil; sun; 3′ to 5′ feet; 1′ to 3′ feet; evergreen
  • Shrub bush-color (Lespedeza bicolor)—dry, well-drained, light, airy soil; sun; 3′ feet apart; 3′ to 5′ feet
  • Shrubby St. Johnswort (Hypericum prolificron)—dry or moist soil; sun or part shade; 2 1/2′ feet apart; 3′ to 4′ feet; yellow flowers
  • Siebold weeping forsythia (Forsythia suspensa sieboldii)—well-drained soil; sun; 4′ to 5′ feet apart; 4′ to 8′ feet
  • Summer grape (Vitis aestivalis)—dry, well-drained soil; sun or part shade; 4′ to 5′ feet apart; deciduous vine

Species Starts With Letter T

  • Tamarix savin juniper (Juniperus sabina tanutrisifolia)—dry, well-drained soil; sun; 2′ to 3′ feet apart; 3′ feet; evergreen
  • Tibet honeysuckle (Lonicera thibetica)— well-drained soil; sun; 3′ feet apart; 3′ to 5′ feet; red fruit

Species Starts With Letter U

  • Ural false spirea (Sorbaria sorbifolia)— dry, well-drained soil; sun; 3′ to 4′ feet apart; 3′ to 5′ feet; white flowers

Species Starts With Letter V

  • Virginia creeper (Parthenocissus quinquefolia)—dry, well-drained soil; sun or part shade; 4.5′ feet apart; deciduous vine; fall color
  • Virginia rose (Rosa virginiana)—well-drained soil; sun; 3′ feet apart; 3 to 6; pink and rose flowers; fall color

Species Starts With Letter W

  • Warminster broom (Cytisus praecox)—light, airy, dry, even poor soil; sun; 3′ to 4′ feet apart; 3′ to 5′ feet
  • Winter jasmine (Jasminum nudiflorum)— dry, well-drained soil; sun; 3′ to 5′ feet apart; 3′ to 5′
  • Wolf’s lilac honeysuckle (Lonicera syringantha wolfii )—well-drained soil; sun; 3′ to 4′ feet apart; 3′ to 5′ feet

Species Starts With Letter Y

  • Yellow-root (Xanthorhiza simplicissima) —moist, well-drained soil; sun or shade; 2′ feet apart; 2′ feet; fall color

44659 by Dr. Arthur T. Viertel