- Sampling depths vary depending on the plant selection.
- For turf: the critical depth for preplant consideration is 0 to 6 inches
- Shrubs: 0 to 18 inches
- Trees: 0 to 24 or 36 inches
- For deep-rooted plants with salt intolerances, sample multiple depths separately (i.e. 1, 2, 3 feet).
- Imported soil should be sampled separately. Many times, imported top soil is poor in nutrition and high in pH and salts. Know where imported soil, cuts and fills are located.
- In a mixed landscape with problems, notice whether the affected plants are shallow, medium or deep rooted. This information will give you an idea of what depth to sample.