When we talk about topsoil versus compost, it is not really so much a competition but knowing when to use either compost or topsoil.
In a bubble, it wouldn’t be the decision of topsoil or compost in a brain-buster about gardening.
There is not necessarily one that is better than the other, because their primary uses are distinctly different.
It would be like choosing who is better at the quarterback position in football, a wide receiver and a running back? It just depends on what you are trying to accomplish, landscaping or gardening.
Topsoil is soil that is primarily found from the detritus of construction leveling and grading.
The bulldozers are rolling through, scraping off several feet up and leveling off the landscape, while you’ve watched deposits of soil that may ultimately end up in the garden aisle.
Compost is made up of materials that have decomposed into organic matter, saturated with nutrients and materials for which plants feed on.
It’s improving the soil around it with the caveat of hidden weeds and unfriendly plant life.
What Is Topsoil Used For?
There is definitely a nutritional deficit from topsoil, as it comes from the very top layer of the earths bedrock where the vast majority of plant life is able to grow.
Generally, topsoil is nutrient rich, and used primarily and best for landscaping, leveling, and grading.
However, in gardening, you will need to scrape the topsoil away, and any bad layers: sand, clay, and of course any soils tufts-full of weeds, which are not the quality you want, before adding topsoil back in.
You want to add bags of topsoil (and replace) the bad earth you scraped away, to gain back the level you intend to grade off.
Preparation: So, now you are left with a good base to start with considering your garden. It will not be all it needs to be, yet, but it is still a good start.
What Is Compost Used For?
Compost is mainly utilized to enhance the quality and nutrition of the soil it’s added to. Compost has many benefits, including having nutrient-rich content, neutral pH level, disease control, great water retention, and moisture control.
Once you have an effective layer of leveled topsoil, you can add your compost.
The simplest way is to till or rake the topsoil. You can then layer soil and rake it in until it’s mixed thoroughly.
The compost will add viability and nutrients to the topsoil, and help retain a sufficient level of water, without draining too quickly.
Put another way, it will create a favorable environment for healthy plant growth.
What Are the Drawbacks of Topsoil and Compost?
The disadvantages are that, independently speaking, the use of each isn’t as powerful or effective as being cut with another.
The compost, alone, lacks density to properly grow strong roots and to anchor the plant, while topsoil is not under federal regulations, is not standardized, and often carries over weed seeds.
Disadvantages of Topsoil
- Susceptible to too much water retention
- Carries seeds from weeds
- Compacts too easily
- Lacks the complete nutrition necessary for good plant growth
- Erodes too easily
Topsoil is damaging in that there is a greater likelihood of weed seeds being present in it.
That said, whether you use compost or not, it is likely they will germinate and you will be controlling weeds in order for your garden to thrive.
Topsoil is also not a great choice for water retention.
For one, it takes heavy rains and water logs, erodes it, and compacts it, so the topsoil can hold too much water, and sometimes not enough when you want it.
And while there may be some good nutritional value from topsoil, it is often not sufficient for a “regular” garden’s growing requirements.
Disadvantages of Compost
- Has an unattractive smell
- Alone, it makes for an ugly garden
- Attracts things better left to the wild
- Requires a larger upfront investment
- Neighbors may not like you
Compost can have an unpleasant smell. Though that may not appeal to you, it is guaranteed to appeal to the bugs, snakes, rodents, and other vermin you do not want to attract.
Also, unless and until it is mixed well and dug into the topsoil, it does look like complete rubbish, or put another way, it looks terrible.
If you are in a tight neighborhood and you decide to use compost, you might guess that it would bother your neighbor, if not your immediate neighbors.
Decomposing organic matter is never pleasant to one’s olfactory senses.
It takes time, heat, and it takes movement to efficiently decompose organic material into a good organic nutrient-rich material.
You might want to consider that you would need to buy a tumbling composter, and then work quite a bit to obtain a small amount to start with, something like this.
How to Find a Good, Dependable Topsoil?
As discussed previously, topsoil is unregulated, meaning there’s no guarantees that it is of sufficient quality for gardening.
Sure, it might say “Topsoil” on the bag with as many punctuation marks as a florist shop – but at the end of the day, it is only your skills that can properly judge the quality of order that construction up.
You’ll want to sift through it before you even buy it, double-checking for excess sand and twigs and rocks.
Once you give it the “tw-substance” test, if you find there are too many, you can pretty well rule out quality lumber.
A good bag of topsoil will have quality topsoil, without too much excess in terms of twigs and rocks and sand.
If “good topsoil” is the measure, amateurs everywhere have produced it; we sort of, on purpose, left some of it behind as a mark of quality.
Of course, there is going to be some level of sand in a bag of topsoil. The point is not a stand of so much that it is basically limited the general quality of it.
Sand is not nutrient heavy, tends to be heavily compacted, and doesn’t function very well in terms of soil retention. The less of it, the better.
How Do You Find Quality Compost?
The most effective way to ensure you are purchasing high-quality compost is to create your own.
This way, you are in charge of the moisture content and ingredients, as well as handling the heating process.
If making your own compost is not an option, you’ll need to try to find something that has controlled ingredients and not overloaded with pesticides and/or herbicides.
Again, just like with the topsoil, you should fully inspect the compost.
Quality compost shouldn’t have partially decomposed materials. You should not find any twigs, mulch, or trash.
Adequate compost should be broken down to small pieces and should be moist to the touch, but not dripping wet.
If you’re looking at a larger project, please keep in mind that you’ll be mixing the compost in with a good amount of topsoil, so please purchase plenty of compost or make a good amount of compost yourself.
Plenty of compost calculators are available online to help you determine how much compost you’ll need based on the square footage of your lawn or garden project.
If you’re thinking about a decently sized garden project, be prepared to buy or create a larger quantity of compost.
For the committed, if you’re creating your own compost be prepared to spend a great amount of hours checking temperatures and rotating the tumbler.
All Things Considered
Rather than viewing the question as “Is compost or top soil better?,” think of it as a combination project.
What will compost do to improve the top soil? How much top soil will you need to properly lift this out before you can bring in the compost?
These are NOT mutually exclusive of one another and are best when used together for the best bang-for-your-buck.
While compost will provide your garden with the nutritional value that it lacks, top soil will level it off and provide its own nutritional value while lending a high standard aesthetic so your garden looks nice.
And most importantly, you will have the best of both worlds while not shorting your garden or landscape from resources that it needs to thrive. A garden is only as good as what you put into it, after all.