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Topsoil is the top layer of garden soil. This comprehensive topsoil guide will allow you to understand the key components of topsoil, what topsoil is used for, and how to maximise the potential of topsoil.
What is topsoil?
Topsoil is the top layer of soil in any garden or field. Usually, it refers to a depth of between 5 to 20 centimetres down.
The topsoil layer is where nutrients are delivered to plants, where water is absorbed, where sunlight helps to aid the growing process, and where earthworms and microorganisms interact with the plant in various ways. This makes topsoil the most productive and important section of garden soil.
What does topsoil have in it?
Topsoil is a mixture of sand, silt, clay and broken-down organic matter, called humus. Humus is rich, highly decomposed organic matter mostly made from dead plants, crunched-up leaves, dead insects and twigs. Topsoil is not weed-free as a general rule, as it has not been treated to remove weed seeds.
“Topsoil is that all important outer layer that supports plant hydration.”
How is topsoil different from other types of soil?
Topsoil is the upper, outermost layer of your garden, it is where the majority of microorganisms, biological soil activity, and plant roots fall.
Products like compost and garden mix are frequently added underneath or within topsoil to increase its functionality, including improving the texture of topsoil.
Topsoil vs Compost
The difference between topsoil and compost is that compost isn’t actually ‘soil’. It is a blend of natural materials broken down into organic matter rich in nutrients that serve as a natural fertiliser.
Compost can be added to topsoil to improve its structure, reduce compaction, and improve water retention and drainage.
Topsoil vs Garden Mix
The difference between topsoil and garden mix is that topsoil is a versatile landscaping material used for various purposes, while garden mix is a soil-less, weed-free blend, ready for planting into, that has been enriched to enhance its suitability for plant growth.
Topsoil vs Nutra Soil
Nutra soil is a 50/50 blend of topsoil and garden mix, offering the best of both worlds: the heavier texture of topsoil and the fertilisers and compost components of the garden mix. Due to topsoil being present this mix cannot be sold as ‘weed-free.’
Topsoil vs Potting Mix
The difference between topsoil and potting mix is that potting mix is commercially manufactured to meet the specific requirements of plants that are grown in pots or containers.
Topsoil is mostly used for landscaping or to be added to other types of soil in gardens or raised beds. Unlike potting mix, topsoil will often contain decaying organic matter, sand, clay and other materials.
Products covered in this topsoil guide
Central Landscape Supplies selects its Premium Waikato Topsoil from approved and tested piles around the Hamilton area. Use our Waikato topsoil for the base to lawns or to build up garden beds and layer our weed-free mixes on top.Order Online
As the name suggests Auckland Topsoil is sourced locally from around the Auckland region. Although it is not as consistent in quality as our loamy premium Waikato Topsoil, this soil is a great ‘filler’ for budget projects.Order Online
Premium Garden Mix is a blend of composted bark, chicken manure, gypsum and slow release fertilisers. This mix is suitable for planting directly into and for filling raised beds and planters.
What is topsoil used for?
Topsoil is used widely in gardening and landscaping. Continue reading below for some of topsoil's most common uses.
5 ways to use topsoil
1. Topsoil as a base for a new lawn/topping up an existing one
Topsoil is an ideal base to fill or level an area that is being sown for a lawn. It should also be used for filling deep (+5cm) holes in existing lawns. Because it is not weed free, it is recommended to cover topsoil with a lawn mix such as Premium Lawn Soil before seeding the lawn.
The top layer will encourage the grass to germinate, offer nutrients to nourish young grass and be weed-free. The topsoil beneath offers the perfect structure to encourage the grass roots to grow down and aids good lawn establishment.
2. Fixing bumpy lawns with topsoil
Sort out those lumpy bits in your lawn with some Auckland Topsoil or Premium Waikato Topsoil. Chuck a decent pile of it into the gaps, about an inch high. Make sure to spread it out evenly but not squash it down too hard, so there's room for the grass to do its thing. This method works best when you team it up with other tricks for sorting out dodgy lawn spots.
Your lawn's bound to look mint because topsoil comes packed with all the good stuff for grass. Those patches will be sweet as in no time. If you're in a hurry to fill those gaps, scatter some grass seeds on the topsoil. Then, give the areas around the gaps a bit of a dig and water the grass like it's your new pet.
3. Sorting out the garden swamp with topsoil
When your garden turns into a bit of a swamp, topsoil's your go-to. Use it to cover up those annoying puddles and fill in the low bits where the water likes to hang out. For best results, mix it up with some sandy soil and dump it on the parts of the garden that can't handle their water.
This way, the soil will chill out and let the water do its thing properly. Give the area a good going over, chuck in a decent amount of topsoil, and your plants will thank you for the extra space to spread their roots.
4. Topsoil for garden beds
Turns out, topsoil is the MVP when it comes to starting a garden. It's the secret sauce for seedlings and grown plants alike. The more topsoil you chuck into your garden, the richer the soil becomes.
Plus, it's perfect for fixing up those worn-out patches thanks to its just-right density and top-notch nutrients.
5. Topsoil for composting
Your typical compost is a mix of organic goodies, a splash of moisture, and some bacteria doing their thing. But, it needs a good spot to work its magic. Enter topsoil – the primo choice for a compost bed. With its similar materials and nutrients, it's like a match made in gardening heaven.