Assessing Your Soil

Different Soils

Your yard and gardens will contain a variety of soil types at differing depths. These types fall into a number of textures, which very broadly are silt, sand, and clay. The proportional mixture of soil types, when combined with coarser material and organic matter, tell you how fertile and easy to work your garden soil is going to be. These combinations will also determine how well drained your soil is, which will help you decide when to cultivate your herbs. Soggy soil, for example, is not only much harder to work, but also results in compacted puddles.

As you dig deeper, the soil is likely to gradually change from the top humus or organic-rich layer through a heavier (or perhaps more sandy), compact layer, until you reach a layer in which it would be impossible to grow a herb. It is important not to bring any of this poorer subsoil to the surface as it may impair the fertility and texture of the topsoil, which can vary considerably in thickness, even within the confines of a small garden.

Enlarge Photo+Shrink Photo-DK - Simple Steps to Success: Herbs © 2009 Dorling Kindersley Limited

pH Test

This important test measures the alkalinity or acidity of your soil on a scale from 1 (acid) to 14 (alkaline) and so helps indicate what types of plant can or can’t thrive in your garden. Cheap testing kits are reasonably reliable and readily available with almost instant results if the instructions are closely followed. Try to take a number of samples, as many gardens vary from one end to the other. Remember, too, that most herbs happily grow in the range 5.5 to 7.5 and if your test results are consistently outside this range, it would be well worth seeking a second opinion or engaging some professional advice before attempting to remedy the situation.

Enlarge Photo+Shrink Photo-DK - Simple Steps to Success: Herbs © 2009 Dorling Kindersley Limited

Test Your Soil

If you are planning a new herb bed or taking on a new patch for the first time, it is important to find out more than just the soil pH. Dig a hole about 8 in (20 cm) square and to a shovel's depth — it is well worth digging at least one hole every 15–30 ft (5–10 m). Pause to inspect the soil you are excavating. If it is dry and dusty, it is likely that you will need to add moisture-retentive organic matter, or if it is sticky or slimy, extra drainage will be a priority. Small stones and gravel shouldn’t be a problem as long as there is an equal amount of soil, but large rocks will need to be removed. On new-build or recently renovated sites there may be a thick layer of rubble or clay not far below the surface, which would need to be dug out and removed.