How to use soil conditioners

Soil conditioners are added to the soil to improve the effectiveness.  There are a wide variety of soil conditioners which perform different functions.  Some soil conditioners can sweeten acid soils while others break up clay-based soils to improve soil structure.

What are soil conditioners

Soil conditioners improve nutrient levels, water retention and soil structure.  A wide variety of soil conditioners include products such as Lime, Dolomite Gypsum, Blood & Bone and Compost just to name a few.  Each has a different function and can be used in a number of ways.

Lime

Lime is a naturally occurring mineral used to sweeten sour or acidic soils.  It helps to provide calcium to the plant roots, which is an essential nutrient and raises the PH and assists in releasing nutrients trapped by the acid soil.

Lime is great for use when growing beans, peas, cabbage, cauliflower, lettuce, sweet peas and tomatoes. Work 125 grams per square metre into soil before planting.  For lawns, Spread evenly 125 grams per square metre and water in well.

Do not add lime if you are planting acid loving plants such as azaleas, rhododendrons, camellias or magnolias.  Some natives are also not suitable to be treated with Lime.

Gypsum

Natural Gypsum is used for breaking up heavy clay soils that cake or crust therefore improving drainage and aeration.  It can be used twice a year and regular use will improve the structure of the soil.  Gypsum is not acid or alkaline so will not affect the natural PH of the soil in any way.

Gypsum can be used on lawns in Spring and Summer. Spread 125 grams per square metre, rake in and water well.  The lawn may initially turn yellow but this will disappear with watering and feeding.

For new garden beds, apply 1kg per square metre and work into the soil before planting.  Gypsum can be applied to the top 20 cm of established garden beds.

Blood & Bone

Blood and Bone is both a fertiliser and a soil conditioner and improves soil drainage, aeration and water retention.  It is a pure source of Nitrogen, Phosphorous and Potassium.  Spread 50grams per metre prior to planting flowers and vegetables. Blood & Bone is also beneficial for Fruit and Citrus trees, roses and lawns.  Apply 100 grams per square metre to lawns in August and March. Rake and water in immediately after application.

Dolomite

Dolomite raises the PH and assist releasing Calcium and Magnesium trapped by the acidic soil.  It can be used in garden beds and lawns. Spread 250 grams of dolomite per square metre in garden beds and work into the top 7 cm of soil.  Add 125 grams per square metre to lawns and water well every second year.

Do not use Dolomite on acid loving plants such as Azaleas, Camellias or Magnolias or some Australian native plants.

Composts

Composts are soil conditioners and can be mixed in to the soil to improve soil structure and nutrients.  Compost encourage microbial activity which benefits the health of the soil and improves its water holding capacity.