The Online Gardener's Handbook 2010
Chapter 3: A Word about Soil
Soil Testing

Table of Contents

  1. Introduction
  2. OMAFRA Accredited Soil Testing Programme
  3. Learn More


Home gardeners in Ontario spend a lot of money on fertilizers each year. This is done in the hopes of achieving high yielding fruit and vegetable crops, colourful flower gardens, and vigorous trees and shrubs. These gardeners will only be successful, however, if their fertilizer use is reflective of the natural fertility level of the garden soils and the amount of compost and manure also being incorporated into the soil.

Soil testing is a way to help gardeners understand the nature and fertility of their soil. It also helps protect the environment by providing gardeners with fertilizer recommendations reflective of their particular garden. Plants respond in a very positive way to nitrogen, phosphorus and potassium when applied to low fertility soils. For many established gardens, where there have been regular applications of fertilizer, manure and compost over the years, anything but a minimal application can prove to be excessive. Plants become too tall and leafy, flower poorly, set fruit poorly and are easily bent down in wind or heavy rains. Soil testing is the most accurate tool available to determine the amounts of fertilizer required for optimum plant nutrition while minimizing the possible leaching of excess nutrients.

OMAFRA Accredited Soil Testing Programme

The OMAFRA accredited soil testing programme for home gardens and lawns provides recommendations for nitrogen, phosphate and potash along with a recommendation for the amount of lime to apply if required. The recommendations are designed to provide good plant growth while preventing or correcting nutrient deficiencies. Sampling every two or three years is recommended.

Several laboratories are accredited to provide a soil testing service to home gardeners. See Accredited Soil Testing Laboratories in Ontario.

Soil Sampling Procedure

  1. Use a soil sampling tube, shovel or spade.
  2. Remove four or five cores or slices, 15 cm deep, from different locations in the garden. (Parts of a lawn or garden that differ in soil texture or in fertilization practices should be sampled separately.)
  3. Mix cores together, and break up any lumps.
  4. Draw the sample for analysis from the combined cores.

Learn More

For more information:
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