Five Types Of Garden Fertilizers for Dog Owners To Avoid

Five Types Of Garden Fertilizers for Dog Owners To Avoid

Health & Safety

The onset of spring means that many of us begin to look forwards to spending more time outdoors, and planning ahead for summer barbecues, paddling pools for the kids, and lazing around on the lawn.

For dog owners with a garden who already have one eye on summer fun, this means that the start of spring usually sees the start of a lot of garden-related activity, tidying up after the winter months, trying to undo the damage of months of the dog toileting on the lawn, and planting plants and flowers to hopefully achieve some impressive summer blooms!

All dog owner with a garden needs to think carefully about anything they plant, use, or bring into the garden, assuming that the dog uses it too; and this means everything from avoiding certain types of plants and flowers that can be toxic to dogs, to ensuring that you don’t leave tools or hazards lying around that might endanger the dog.

When it comes to pesticides and things to kill garden pests like aphids, weeds and bugs, it is self-evident that some of these may pose a danger to animals like dogs, and most dog owners naturally check such things very carefully to make a safe choice.

However, fertilizers – to encourage your lawn to grow or make it greener, to get seedlings off to a good start, or to help you to produce more prolific and impressive blooms – can pose a hazard to dogs too, including some naturally occurring and organic ones, the latter of which catches many dog owners by surprise.

With this in mind, this article will tell you about five common, popular and easy to buy garden fertilizers that can be hazardous to dogs, and why they’re a potential problem. Read on to learn more about what fertilizers you can’t use if you have a dog.

Cocoa mulch

Cocoa shells are often used to top off flower beds as garden decoration rather than being a fertilizer per se, but cocoa mulch, which doesn’t look quite as recognisable, is a common natural and often organic fertilizer for flower beds.

Cocoa mulch (and cocoa shells) are a by-product of the cocoa harvest, and all dog owners know that cocoa and chocolate are toxic to dogs. Whether or not the average dog is likely to try to eat cocoa mulch is debatable, but many dogs dig up flower beds, so play it safe and avoid this potential garden toxin.


Iron is not often sold as a fertilizer on its own, but it is a common added ingredient in many types of fertilizers as well as something that can also be purchased in small quantities neat to add to or create your own fertilizer mixture.

Iron is a hazard to dogs if ingested because it can result in iron toxicity, which if acute, can go on to cause heart and liver shutdown. Iron is of course also a naturally occurring mineral that dogs (and people) need in their bodies in small quantities for good health, but it can still be a problem in the garden!

Blood meal

The rather unappealing-sounding “blood meal” fertilizer is indeed actually made out of blood, which is probably something you didn’t actually want to know! This is usually produced as a by-product of slaughterhouses, and comes thankfully in dried or “meal” form.

Whilst unpleasant, this might not seem like an obvious threat to dogs, but blood meal fertilizer contains around 12% nitrogen, which is what makes it such a great fertilizer; but also what makes it dangerous to dogs. Ingesting blood meal can cause vomiting, diarrhoea, and potentially pancreatitis. Additionally, iron is sometimes added to blood meal fertilizers too, increasing the danger.


Organophosphates are a common ingredient in fertilizers designed to use with certain types of flowers, most commonly roses. This ingredient is often listed under the name of disulfoton on fertilize packaging, but there are various other types and names used too.

Organophosphates are a problem for dogs because they’re hugely toxic; less than a teaspoon could kill a large dog outright; and they cause a range of acute and serious symptoms that not all dogs recover from, including hyperthermia, breathing difficulties, and seizures. Prompt veterinary treatment is essential to increase your dog’s chances of survival if they accidentally ingest this; but better still is avoiding it entirely.

Lawn treatments and fertilizers containing pesticides

Some garden fertilizers are all-in-one products designed to help your lawn or plants to grow, and also to kill off weeds or repel bugs at the same time. Such products usually contain some form of pesticides, and these are naturally dangerous to dogs as well as lethal to irritating garden invaders.

Again, the above-mentioned and highly toxic organophosphates might be present in combination products too, so always check the labels carefully.

Always follow usage instructions

Some garden products are only a threat to dogs when they’re wet or freshly applied, but are pet-safe if you keep your dog out of the garden until they are dry, or for a prescribed period of time. Others remain risky all the time, like cocoa mulch.

Always read usage instructions and hazard guidance carefully before you buy a product to use in a garden with a dog, and store it safely out of their reach when not in use too.



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