Is Vermicompost Good For All Plants? Advantages and Disadvantages Outlined

If you have come across vermicompost or you’ve started making it yourself, you may well be wondering is vermicompost good for all plants? Do some plants generally dislike it? After all, plants need very different things from their environment, so how often can you use vermicompost?

Vermicomposting is a rich, useful additive to soil that provides your plants with some key nutrients and can be very good for them, especially plants that are hungry. However, it is not the perfect solution for all plants, and some may actively suffer if you add it to their soil. It’s a good idea to check what your plant needs before putting vermicompost in its pot.

In this article, I will share with you everything you need to know about using vermicompost on plants.

How Is Vermicompost Made?

Vermicompost is a result of using worms to break down kitchen waste and other soft organic scraps. This is a composting method that is growing in popularity because it can be done in your kitchen (or another room in your house) and doesn’t take up a lot of space or need a lot of work.

Vermicompost is the result of the worms eating all the food and then excreting their waste at the end. The resulting worm castings (essentially just worm poop) make up a soil-like substance that is full of nutrients, soft and offers valuable structure to the soil around your plants.

It’s easy to see why you might be tempted to add this stuff to any plants you have nearby, but you should pause before doing so, and do a little more research.

What Are The Advantages Of Vermicompost?

This sort of compost is full of nutrients, meaning that it is a good way to “top up” and enrich soil that is deficient in nutrients. The worms have broken down the organic waste into a valuable source of plant food, and this is the main reason that you might add vermicompost to your plants.

SuSanA Secretariat, CC BY 2.0, via Wikimedia Commons

Secondly, vermicompost is good for the structure of the soil, whether it is clay soil or sandy soil. That is because vermicompost is both porous (and thus helps clay soils drain and increases the airflow) and improves moisture retention.

Digging vermicompost into your garden or adding it to your plant pots can therefore help ensure your plants are getting enough to drink but aren’t sitting in pools of water.

These are the main advantages that vermicompost offers to your plants. They might sound great, but what are the concerns?

What Are The Disadvantages Of Vermicompost?

On the whole, vermicomposting is beneficial to a plant, but there are instances in which it could be harmful. For example, if you add vermicompost to soil that is already nutrient-rich, you could harm the plant, especially if it is a plant that prefers poor soil (as many herbs do).

Although nutrients are usually good for helping plants to grow, enriching the soil past a certain point can be more damaging than helpful. 

If anyone suggests that adding vermicompost encourages root growth, you should dismiss their comment; having nutrients available does not stimulate root growth – it does the opposite, as the plant doesn’t need to spread its roots in search of richer soil.

Another potential issue with using vermicompost is that it can contain pathogens and weed seeds. This is only likely to be the case if you have included meat, pet waste, or weeds in the mix. Worms won’t solve the problems associated with these kinds of waste, and the composting method doesn’t get hot, so they won’t be killed by temperature either.

This could infect new plants with blight or other diseases, or cause seedlings to be swamped by weeds.

Photo by Nicolas DEBRAY via Pixabay

On the whole, however, these are the two biggest drawbacks of vermicomposting. The first can be avoided by knowing whether your plants need more food or not, and the second can be avoided by using a worm bin with care and not adding dangerous ingredients to it.

Should I Add A Lot Of Vermicompost To My Plants?

If you have been vermicomposting for a while, you will probably have noticed that you don’t get much compost for your effort. Although worms do break waste down relatively quickly, it still takes quite a long time for scraps to become something useful to add to the garden, and on the whole, your wormery will not produce large quantities of compost.

This is partly because you will probably struggle to make a big wormery. The worms don’t burrow down very far, so most wormeries are shallow and wide, and this makes it hard to create big wormeries capable of processing a lot of waste.

The good news is that this doesn’t matter too much; you don’t need a huge wormery to get enough vermicompost, because a little goes quite a long way.

On the whole, mixing vermicompost with normal compost will give your plants a great boost without using up your vermicompost too quickly. You may not have a lot of it, but because it is rich, a little should be enough!

Think carefully about which plants need your vermicompost the most, and don’t fling it haphazardly around your garden, or you will very quickly run out. Be discerning about the distribution of this valuable resource, and remember that too much isn’t beneficial anyway.

How Should I Use Vermicompost?

You have a couple of different options for using vermicompost to boost your plants, so we’ll cover a few below.

As A Top Dressing

Many people like to add it as a top dressing to established plants. This is a great way to enrich soil that may have had its major nutrients depleted over time.

If you have a large plant, it is likely to quickly drain the soil of the nutrients it particularly needs. It will then be sitting in soil that contains other nutrients, but not the ones it requires for good, healthy growth – so you need to replenish those nutrients.

To use vermicompost as a top dressing, you first need to separate the worms from it, which can be done by manually picking them out, or by feeding them in a different part of the container for a few weeks. 

Next, simply spread the vermicompost around the plant. For large plants, you will want to work a short way from the stem to ensure you are feeding the roots.

As a guide, look at where the plant’s leaves/branches end and feed around this circle. This is usually where the fine root hairs are growing, and these will quickly take up the nutrients being added to the ground.

Once you have added the vermicompost in a rough circle around the plant, water it well.

Over time, the nutrients will wash down into the soil, feeding the plant’s roots. This is all you need to do to make sure the soil around your plant stays rich even as the plant uses up the nutrients.

Many people suggest using vermicompost on your garden plants as opposed to houseplants or seedlings. Because you won’t end up with huge amounts of it (even if you do have several wormeries), it’s quite a valuable addition, and should be used where it is most needed.

As A Seed Starter

Starting seedlings off in vermicompost is a great way to ensure your plants are healthy and vigorous. You shouldn’t start them in neat vermicompost, however, but instead mix a small quantity of the worm castings with whatever seed starter you are using.

This will boost the nutrients without overwhelming the plants. Remember, too many nutrients at once can be toxic, so always mix the vermicompost with something else, or simply sprinkle a bit on top and water it in.

For Houseplants

Topping up the soil in your houseplants’ pots with vermicompost is a great way to keep them happy and healthy. It can also reduce the frequency with which you need to re-pot them, as it keeps the soil around their roots rich and full of goodness, so you’ll only have to re-pot when they get too big for their container.

To add vermicompost to your houseplants, you can simply scoop off a bit of the surface soil in the pot, and then sprinkle a few handfuls of vermicompost on top. Water it in, and you’re done. 

If the pot isn’t too full, you don’t even need to remove the old soil, although you might want to break it up a bit with a trowel (being mindful of the plant’s roots) to ensure the nutrients can wash in properly.

Do this every few months to keep your plants happy and healthy, and give them a growth boost when they need it. However, do remember not to overdo it, especially for small potted plants. They will need less in the winter, too. If your plant suddenly starts to look unhappy, you may be over-feeding it, especially if you haven’t changed any other aspects of its care.

For Vegetables

Vermicompost can be great if you have nutrient-hungry vegetables. If you’re growing your own food, you’re probably always on the lookout for ways that you can give your plants a boost. Vermicompost is a great option and is thought to give better results than many other fertilizers that you might use.

Again, it is best to use vermicompost as a soil improver; it is not soil in its own right. Sprinkling it on top of your vegetable beds or mixing it into the soil is the best way to give your plants the nutrients that they need.

Most kinds of vegetables will benefit from vermicompost as long as it is not used excessively.

What Nutrients Is Vermicompost Rich In? 

Vermicompost that is well balanced will usually be rich in nitrogen, phosphorus, and potassium, which are the three macro-nutrients that plants need (often abbreviated to NPK). Commercial fertilizers show their balance of these nutrients represented as 10-10-10 or 20-20-20.

It is worth noting that vermicompost tends to be particularly high in nitrogen because the worms compost at moderate temperatures. However, the actual values that you get from your vermicomposter will depend very much on what ingredients you put into it.

Vermicompost also contains important other important nutrients, such as iron, magnesium, calcium, and sulfur. All of these are required for plants to grow, although the quantities that plants need can vary enormously.

Furthermore, there are micronutrients in vermicompost, and these will also help your plants. They include things like copper, zinc, and manganese. These will be released slowly into the soil, and your plant can then take what it needs.

As long as you don’t add too much to your soil, these nutrients should help most plants to grow.

Do Any Plants Hate Vermicompost?

It seems unlikely that any plants would hate to have vermicompost added to their soil because it is essentially just an addition of nutrients. As long as the soil is not already rich in nutrients, adding vermicompost is just improving the plant’s growing conditions.

Of course, different plants need different levels of nutrients, and some plants do prefer soil that is of poor quality. It is a good idea to check how much food your plant likes to have around its roots before you sprinkle piles of vermicompost around it.

You may find that it helps to keep a schedule of when your plants were the last fed so you can refer to this if you aren’t sure whether they need fertilizing or not. This can reduce the risk of over-feeding a plant and ensure you aren’t using up valuable vermicompost where it isn’t needed.

Many plants will thrive in poor soil, including periwinkle, bleeding heart, and lavender. Think twice before giving these a big dose of vermicompost, as they may struggle with the increased nutrients.


On the whole, vermicompost is great for your plants, as long as it is used in moderation. Like anything you add to your garden, you can have too much of a good thing, so pay attention to your plants and their needs.

Using vermicompost all over the place all the time could result in soil that is too rich for your plants to cope with, but when used with care and consideration, vermicompost is a good addition to pretty much any plant’s soil.