Which Plants Should Not Be Composted?

If there is one thing you should know about us, it is that we love composting. It is definitely one of the most effective and eco-friendly ways to get rid of waste and isn’t going away any time soon.

However, not everything can be composted, much to our chagrin. So you need to be in the know of what you should never add to your pile.

Fortunately, we have all the details you seek and are willing to share them with you today.

Plants that should never be composted

Here’s a list of plants that should never be composted:


Unless you are 100% sure that they are healthy, it is best to avoid composting tomatoes. This is because they are prone to disease and can easily infect your whole compost heap.

What’s more, they are acidic and can negatively affect the bacteria in your pile. As such, many composters avoid both tomatoes and their vines. Also, tomato vines have a tendency of tangling up everything in your pile.


While it is understandable to want to add yard waste to your compost pile, you should be wary of adding weeds. They can easily take root and grow throughout your compost, compromising its quality.

So whether you are part of an organic collection program or you are simply composting for your garden, avoid weeds.

Treated wood, wood scraps, and sawdust

Once you treat wood, scraps, or sawdust, you shouldn’t compost them. The chemicals used in the treatment process can compromise your heap and render it useless.

Black walnut trees

Any leaves and twigs from black walnut trees should never be added to your compost heap. They contain a toxic called juglone that is toxic to many plants.

Another thing to avoid adding to your heap is any trimmings from plants that were treated with pesticides – these are toxic as well.


These plants are prone to diseases like blight and mildew. As a result, long-term composters usually advise against adding them to your heap in the first place – they are definitely not worth the trouble they can cause.

Large branches

While small branches are okay for composting, large ones take way too long to break down and shouldn’t be added to your heap. They will just delay how long it will take for your compost to be ready.


Interestingly, there are two reasons you should not add rice to your compost heap.

For one, pests like raw rice and can be attracted by it.

Secondly, cooked rice can breed bacteria that can be harmful to your compost’s nutrients.

Diseased plants

Any plant that has signs of disease should not be added to your compost pile. It can infect your whole pile and reduce the quality of the heap

Garden plants

When it comes to your compost heap, you shouldn’t add garden plants like dandelions and ivy. These plants will only use your heap as a place to sprout and grow instead of decomposing and adding nutrients to your heap.

Plants you should think twice about

Apart from the plants you should definitely avoid, there are some that you can add to your compost with moderation. These include:

Citrus fruits

While you can add citrus fruits to your compost, you shouldn’t overdo it. When in excess, these fruits increase the acidity of your compost and make the decomposition process even slower.

Greasy vegetables

While vegetables are usually a great source of nutrients for your compost, when they are covered in oil, they become unsuitable for this use. They can even affect your heap negatively.

Other substances you should not add to your compost

Apart from the above mentioned plant-based products, here are a few other items that you shouldn’t add to your compost:

Meat products

Whether it’s beef, chicken, or fish, you should never add meat to your compost heap. Not only does it decompose slowly but it also produces strong odors that can attract pests and animals.

So if you already have a pest problem, meat could be a disastrous addition.

Dairy products

If you don’t want to worry about attracting pests to your compost, you shouldn’t add any dairy products like milk and yogurt to it.


Both human and animal feces are usually bad for your compost heap. They can add pathogens to your heap and are generally a health risk.

However, waste from non-carnivorous animals can be good for you. Bee droppings are particularly helpful as they contain pollen and other helpful nutrients.

Personal products

Any used personal products should not be added to your compost heap. These include used tampons and diapers – they pose a health risk.


If there is one thing you should know about bread and other pastries, it is that they easily attract pests and other animals. So adding them to your compost pile is a definite no-no.

Cooking oil

This is yet another addition that attracts insects and animals to your compost pile. Moreover, it can slow down the composting process and mess with the moisture levels in your compost.

All these factors eventually affect the quality of your compost and how long it takes to be ready.

Fruit stickers

While they are easy to miss, fruit stickers aren’t good for your compost.

They are one of the most popular compost contaminants and can’t break down even in industrial composting facilities. That is why it is integral to get rid of all of them before tossing any part of your fruit into your compost.

Alternatively, you could try to source all your fruits directly from the farmers – these come with no stickers.

Concentrate on what you can add

Ultimately, one of the best ways to ensure that your compost is high quality is to concentrate on what you do want to add instead of what you intend to exempt.

So, incorporate as much nutrient-rich green waste as you can and always remember to add carbon-rich brown material like shredded paper and dry leaves. This will balance everything out. And the more balanced your compost the better!

Leave a Reply

Your email address will not be published. Required fields are marked *