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Application of Compost for Different Soil Types

Written by on August 2nd, 2018.      0 comments



Above: Vineyard soil with compost applied under vine 6 months ago (left) and soil that was taken from the nonapplied area within vineyard (right).

Soil performs vital functions in our ecosystems. The soil stores reserves of water for plants, controls water seepage into streams and groundwater and reduces rapid runoff that could cause erosion and floods. The soil stores carbon, (storing about four times more than plants), so it helps minimise the release of carbon dioxide into the air. Soil microbes absorb nitrogen from the air and make it available as plant food. Nutrients are released as underlying rock fragments decay. Soil filters water and helps absorb and break down toxins.

How can you best improve your soil so that it is more productive? Here, at Wholesale Landscapes we operate under a set of core values, one of which is resourcefulness. We believe in being resourceful and making the most of what we’ve been given. That is why we utilise forestry residue and other waste bio-products to create composts that will enhance the productivity of your residential garden or horticultural enterprise.

For a small country, New Zealand has a wide diversity of soils. According to the New Zealand Soil Classification, there are 15 main types of soil.  For example, Nelson and Marlborough soils fall into the general category of ancient soils, which through long weathering have a high clay content, are generally acidic and of low fertility.


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Soils in Otago are considered semi-arid, where there is too little rain to wash out the sodium, calcium and other elements released from the slow weathering of the parent rocks. Nutrient levels are relatively high but the soil must be irrigated to produce a crop.

Hawkes Bay soils are mainly silt loams, and in the east where there is less rainfall, and on flat or undulating land, there may be compacted subsoils.

So what elements define a good soil? It needs to be deep, fine-textured, moist, free-draining, loamy, and have an organic-rich topsoil. These properties best enable plant roots to take up nutrients, water and oxygen to support rapid growth.

What remedial action can you take if your soil does not have these elements? In terms of gardening, reference is generally made to 3 types of deficient soil; clay, sandy and rocky. 

A soil with a high clay content can be greatly improved by the addition of compost. It improves drainage while maintaining the water-holding capacity of the soil and improves the granular structure of the soil by interrupting the aggregation of the clay particles. This improves the soil porosity so that air and water can move freely through the soil. Compost will make this type of soil less sticky and more friable and will reduce the bulk density of the soil helping it resist compaction and enabling plant roots to better penetrate the soil.

Wholesale Landscapes’ HortGro Compost, a free-flowing, nutritious blend of aged, fine bark, mulch, freezing works’ waste bio-products and other active fertilising ingredients, is the ultimate soil conditioner. It can improve soil structure by increasing organic matter and carbon content, improving nutrient uptake to give healthier and more productive plants.


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The application of compost to sandy soil greatly improves water retention and helps keep fertilisers and nutrients in the root zone, preventing them from being leached into the ground water. The humus produced by the decaying compost helps bind soil particles together making a better-aggregated soil, which will hold water while allowing air and roots to penetrate, as well as improving erosion-resistance.

As sandy soils are generally low in nutrients, the application of a product such as Wholesale Landscapes’ FishGro Compost, made from marine bio-products and organic bark fines, will provide a great moisture-retaining foundation for roots to quickly access much-needed nutrients and trace elements.

Rocky soils are usually very low in plant nutrients and have limited moisture retention so would benefit from the application of a compost like Wholesale Landscapes’ Flourish. Trusted by many New Zealanders and very popular with hobby gardeners and landscapers, Flourish has a mushroom-compost base which promotes beneficial microbial activity in the soil. It contains animal manures to provide a rich source of nutrients, screened bark fines to help stabilise pH levels and add carbon content, all combining to create a perfect environment for root generation and ongoing plant growth.

No matter what the deficiency in your soil, Wholesale Landscapes have a compost solution for you.

For individualised advice, please contact Wholesale Landscapes at:



Freephone: 0800 421 000





About Us

At Wholesale Landscapes, we supply a wide range of landscaping products that are aged and blended to ensure the absolute highest quality. We deliver commercial quantities of bark-based landscape supplies to resellers and projects across NZ. We have a trade yard in Stoke, Nelson where landscapers and contractors can conveniently pick up bulk landscape supplies - all year round.

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