Better Landscaping Today Newsletter

Volume 1, Issue 2                                                                                                                                 September 1998

LANDSCAPING NEW CONSTRUCTION SITES REQUIRES BETTER PLANNING AND PRECISION FOR SUCCESSFUL RESULTS by Garn Wallace

Have you ever wondered why it was more difficult to establish new landscaping on new construction sites than it was on renovations?  Disturbed soil landscaping sites are much more difficult sites for the successful establishment of new landscaping.  Ungraded sites are easier because of the presence of topsoil formed by weathering of the subsoil and formed by the products from native vegetation.  Normally, the topsoil is only 6 to 12 inches deep.  The topsoil has a higher concentration of plant nutrients than the subsoil.  Organic matter has increased in this shallow depth because of root growth from the native shrubs which have grown, died and have been replaced with new root growth or new plants.  Not only is the topsoil more fertile, but the topsoils have other growth promoting properties-less compaction, better drainage, better aeration, better tilth etc. - than the subsoils.

The difficulty of landscaping these sites where excavated soils have been used for the final grade is the identical problem strip mining firms have in revegetating the replaced overburden.  The soils have been disturbed and the topsoil is interdispersed throughout the subsoil.  Strip mines have the economies of scale and the use of farm equipment, but they still need to spend at lease $5,000 per acre for land restoration planting from seed.

Desert Soils

Inland soils in hot, dry areas; sandy soils; and infertile soils have additional limitations.  Native vegetation is sparse with many feet separating each shrub.  Over the centuries, the plant nutrients have been removed from the soil surrounding the shrubs and transported to the shrub via the root system.  As shrubs die back and new ones replace old ones, "fertile islands" have been formed under the shrubs.  Wild life use the shade of the shrubs for their habitat and deposit manure there which also enriches the soil.  If these fragile soils were collected 6 inches deep and then graded back into place, the soils would be infertile with a very low chance of plant growth.  In addition, the foraging pressure of the wild life will reduce the probability of the establishment of new plantings.

California Soils/low Organic Matter

California soils have about 1/4 the organic matter (O M) content of the Midwestern soils.  It is the organic matter that naturally improves the tilth and friableness of the soil.  The O M content is low in the western soils, due to the long, dry, hot summers in which the organic matter is oxidized by the soil microbes, and by the lack of new plant growth.  The addition of most organic amendments does not really replace natural soil O M because of major differences in the two types.

Landscaping in subsoils actually requires land reclamation for the success of projects involving new construction.

LAND RECLAMATION FOR EXCAVATIONS, GRADED SITES OR BARREN AREAS

Soil preparation of these inhospitable sites requires procedures and methods for (1) the establishment of fertility, (2) the reduction of trace element toxicities and (3) the creation of soil porosity with the other desirable physical soil properties.  The fertility requirement transcends N-P-K.  All essential nutrients need to be evaluated and not just with soil level measurements but with relative abundances.

Organic soil amendments are not able to adequately amend these soils without the use of more powerful soil conditioners.  Polymers like Complete Green® Soil Drain™ are about 500 times, pound per pound, more effective than organic matter in enhancing the soil in order to form the open texture and to create porosity as found in the prairie land soils.  On a cost effectiveness basis, the Soil Drain™ technology is cheaper than the sole use of organic amendments because the Soil Drain™ polymers function identically to natural soil organic matter which unfortunately differs from purchasable materials.

If you would like helpful information, e-mail info@wallace-labs.com indicating your needs:

                O Fertility considerations for landscaping.

O How to specify Complete Green, & Soil Drain™.

O More information on how Complete Green Soil Drain™ works.