Can You Plant Directly Into Compost?

The benefits of compost materials to the plants and soil are far too many for any farmer to miss out on. It’s a direct source of many vital nutrients, which explains why it’s also called black gold.

Compost mixture bears a striking resemblance to the soil, leading many farmers to wonder if they can plant directly into it.

There isn’t a straight answer because of the conditions that apply. So, this blog post will explore that question adequately – keep looking below to discover what you can plant directly into compost and how long it takes this vital component to turn into soil. Enjoy!

Can You Grow Plants With Just Compost?

Magnesium, potassium, and nitrogen are all nutrients that appear in robust supply in compost mixtures. This material improves the quality of soil and plants, inviting the question of whether we can grow plants with just compost. Well, plants can grow in compost, but some will barely survive the experience for a few reasons.  

Compost is made of organic matter, while soil contains additional components like minerals and rock particles. Undoubtedly, plants need both structures but are likely to thrive better in garden soil than in compost.

The reliance of plants on the minerals and rock particles in the soil makes it somewhat tricky for them to grow in an environment devoid of them. But again, it is undoubtedly tempting to fill a pot with the compost mix and grow plants. After all, it’s direct access to all the nutrients required for growth.

However, the materials that make up the compost have their purpose – the nutrients they offer plants and can be dangerous when you expose your flowers to an overload.

You can grow plants with just compost, but there’ll be apparent deficiencies even if the said plant survives till maturity. Compost mixture is essentially decomposed organic matter, so it drains fast. For instance, it dries out when you leave a portion of compost without soil support.

This is advantageous when you combine it with garden soil because it improves the drainage system.

On the other hand, it has a detrimental effect on the plant because its root will be unable to access adequate moisture. Since the compost mix lacks soil, it dries out and starves the plant of water.

Another reason to avoid growing just plants with compost is how easily compost mixture compacts. Wetting your plants is an inevitable aspect of plant care, but the more water you add to compost without including topsoil, the more it shrinks.

You can save yourself and your plants the pain by creating a balanced soil and compost mix.

One of the most suitable ways to use compost is applying a layer to your garden soil mix. Here, plants and the soil will both benefit, and you’ll get your desire to provide your plants with enough nutrients.

What Can You Grow Directly in Compost?

There are some plants that you can grow directly in compost. It can hold some plants that don’t require structural support. Their roots will balance without toppling over the branches and fruits.

Examples of plants that can grow in compost include vegetables, baby carrots, baby tomatoes, and spring onions.

Although abundant nutrients can be found in the organic matter mix, growing your plants in compost mix would be cutting them off from access to the myriad of benefits the soil offers them. If anything, only 5 percent of organic matter should suffice for healthy plant growth.

But again, growing a plant directly in compost is achievable. You can plant vegetables like spring onions, baby carrots, zucchini, cucumbers, and tomatoes, but only because they’re smaller plants with lighter weight.

Planting any crop in compost alone will massively deny its access to the best nutrients and growth conditions. Instead, you can leave a thick layer of compost, about five to six inches, above your garden bed.

So, your new plants can benefit from the nutrients organic matter offers without missing out on what garden soil also provides.

However, it would be best if you regulated the conditions. For instance, you can grow vegetables directly in the compost if you measure the pH content. If it falls between 6.0 to 7.0, it’s an excellent environment for them.

You can also inspect the content of the pile. Uniformity on its composition shows that it’s ready for use.

But again, structural support isn’t the only reason plants need soil. They also need it because it’s solid enough to hold their weight even while wet.

It would be best to wet your plants regularly because they can’t rely only on the compost mixture’s nutrients. Compost is essentially organic matter; it has no sturdy substance to rely on. So, your makeshift soil shrinks when you keep adding water while caring for your plants.

Can You Start Seeds in Compost?

If it’s almost planting season for you, we bet there are many things running through your mind. Planting for the new season is a big step, and you’ll do what it takes to make it successful.

If you’re like the average farmer, it must have crossed your mind that you can start seeds in the compost. After all, this material is similar to garden soil and will give your plants unmitigated access to nutrients.

We want what’s best for our plants, making us think about incredible ideas like starting seeds in the compost. You can do it, and we believe this is one of the more suitable environments because of the abundance of nutrients in the compost mixture.

The seeds will certainly germinate, but only under the right conditions. For instance, the compost material must be significantly decomposed into its humus state before becoming suitable for plants.

Otherwise, the potency of the compost mixture at this state may kill the seedlings.

You can identify a compost mixture ready for use through its smell. Bring a handful close to your nose and observe the scent of rich, dark earth. It also looks crumbly, much like soil. The dark brown consistency will also tell you when to start seeds in the compost mixture.

However, you’ll be unable to grow the plants in the compost after they germinate. That’s because compost is only sturdy enough to bear the weight of smaller plants with less intense structures.

If we’re talking about baby carrots, spring onions, and zucchini, you can leave them on the compost vegetable bed, since the composting mix only covers five to six inches of natural soil. 

It’s also possible for plants to receive an overload of nutrients, which happens when you leave them in compost for too long.

How Often Should Compost be Turned?

Before decomposition takes place, certain factors must be present in a compost pile or bin. Oxygen, heat, and moisture are all required to activate fungi and bacteria.

Afterward, composting begins in earnest. The process requires dedication and adequate attention, otherwise, you may be unaware when the conditions in the compost pile go wrong.

For instance, while your compost pile may not catch on fire, it can overheat if you expose it to unregulated temperature. If it also contains too much moisture, you may be unable to get the fast result you desire.

It’s best to turn your compost mixture now and then to ensure ample aeration. Insufficient aeration will halt the process because microbes need oxygen to breathe.

Even if your compost pile isn’t covered, some internal factors can also cut off air circulation. For instance, compaction occurs when the particles in the compost pile meld too close together, closing the formerly present air holes.

When there’s insufficient breathing space for microbial activity, decomposition slows down. Of course, this means that the composting process comes to a hold until the right environment is created again.

So, when you fluff the contents with a pitchfork, it reintroduces enough air into the pile.

If there’s also too much water, it takes the place of the air pockets, cutting off oxygen access for the microbes. Turning the contents can help drain excess water and ensure adequate air circulation.

Unarguably, the benefits of turning your compost are many. However, you can also interfere with composting if you’re not careful.

Microbes build fragile networks on the surface area of the compost mixture. It spreads over time but can be broken down when you fluff your compost pile too frequently.  

Aerating too often can also delay the heating up process, so you can create a turning schedule. If you use a compost tumbler, once in 4 days will suffice, while compost piles should be fluffed twice weekly.

However, the number of times you’ll turn your compost depends on how large the pile is, the moisture content, and your green to brown ratio.

The more time you spend with your compost pile, the better the chances of creating a superb quality compost mix.

How Long Does it Take to Turn Compost Into Soil?

Farmers don’t mind waiting patiently for their compost to turn into the soil because they know the benefits it provides their plants. It aids water retention in soil, fights diseases, and encourages healthy bacteria growth in the ground.

It takes compost mixture several weeks to months to turn into soil. The timeframe is more definite if you’re hot composting – it falls within 30 to 90 days.

Please note that the soil in question is essentially made of nutrients and organic matter. It cannot replace garden soil but can certainly perform supplemental roles.

Many factors can increase or slow down how your compost mixture becomes soil. For instance, when you use only the best ingredients, you have the assurance that nothing will slow down the process.

Compared to using older organic matter, newer materials contain ample and active bacteria that can contribute to faster decomposition.

Composting takes a more extended period when you use a smaller bin. A larger compost bin will fasten the process because there’s enough room for it to capture and retain heat. It’s also best to purchase an insulated model, especially if you live in a cold clime.

You can accelerate the decomposition process by moving it to a section with sufficient sunlight. This doesn’t mean you should leave it exposed to the sun’s direct rays – exposing your compost pile to excessive sunlight will leave it dried out. So, provide ample shade alongside.

Still, on the size, a compost pile with a height and width of three feet creates the ideal environment for decomposition. Things will heat up faster, especially if it’s made from plastic and wooden bins.


Despite these apparent similarities, compost can’t replace soil. It cannot function independently, particularly in plants that require structural support.

Although compost performs essential functions in plant and soil growth and health, it’s merely an additional component. It doesn’t have the requirements to support plant growth truly.

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About Rinkesh

A true environmentalist by heart ❤️. Founded Conserve Energy Future with the sole motto of providing helpful information related to our rapidly depleting environment. Unless you strongly believe in Elon Musk‘s idea of making Mars as another habitable planet, do remember that there really is no 'Planet B' in this whole universe.