How to use weed killer safely

‘Weeds’, just the sound of that word is enough to flip the mood of an experienced gardener from that of a happy, smiley, garden gnome, to that of a snarling, war-damaged, maniac. For those of us with more than a few years of gardening behind us, this never-ending battle with nature’s most annoying plants is usually high on our list of pet peeves.

Chemical companies know this, and this can clearly be seen by the vast number of different weed killer products that are available on the market in the UK today. It’s so easy to turn on your computer, log in to Amazon, and then choose one of the many weed killers out there to be delivered to your door.

As they are so easy to get your hands on, some people don’t give these products the respect they deserve, safety-wise, and don’t seem to realise that mishandling them can be dangerous, not only for themselves but for their family members, pets, and other plants in their gardens.

This article has been written to try to make people more aware of the dangers involved when using weed killers, and try to promote the safe use of them so that nobody will be accidentally poisoned, and your lawn, flowers, and crops don’t have to be wiped out along with the green invaders you are trying to get rid of.

Knowing how to safely use weed killer is an important part of being a gardener, after all, if you let weeds get ut of hand, you could end up like this person-

Always read the label on your weed killer before using it

It seems pretty obvious, doesn’t it? But there are a lot of people out there who will jump straight into using a strong weed killer without reading the label and instructions, or at most just give them a quick glance without really taking in the information. There is a ton of important information on the label of any weed killer, including weed and feed products, and before you open the container, you should make sure you have read it all. Some of the things you should see are-

The level of toxicity
Different weed killers have different toxicities, and the label should show this clearly through one of the following words: caution, warning, danger, and poison. The word poison is sometimes replaced or accompanied with a skull and crossbones or the words highly toxic.

It is really important to know how toxic your weed killer is as you will have to be extra careful with the products that are higher up on the toxicity scale, like stump removers. Accidentally ingesting the really poisonous chemicals, or even having them be absorbed by your skin, can be extremely hazardous for your health and can even result in death.

You may see that the label on your weed killer has more than one of these words, and that is usually to indicate different levels of danger to you and others through inhalation, skin or ocular absorption, or ingesting, all very important things to know, I’m sure you’ll agree.

Speaking of toxicity and labels, there is much debate going on at the moment over weed killers and just this kind of thing-

Ingredients and is it pet friendly weed killer?

You might have an allergic reaction to some of the ingredients in your weed killer, so read the ingredients and make sure that there aren’t any major issues in that department. Also, while some products may claim to be organic, or natural, they actually contain some harmful chemicals that might need to be looked up, on the internet, before using the product. If you have very sensitive skin, or a lot of allergies, it might be better to go with a weeding tool or lay down a weed membrane instead of using chemicals. If you have pets and children then you definitely want to take a look at our trusted pet friendly weed killer page.


Some weed killers are sold ready to use, like many designed for block paving and patios,  while others arrive as a concentrate and need to be diluted with the correct amount of water. Then there is the fact that this ratio is often different from one product to the next, so you can see why reading the label is really important in this regard. Over diluting a weed killer will make it less effective, while not diluting it enough can cause all manner of other issues, not least of which is killing off your crops and flowers. Here’s a video of someone diluting a concentrate the right way.

Be aware of the different ways toxins can get into your body

Some people think weed killers are only a danger to them if they somehow drink it or splash it in their eyes, but actually, there are a few ways that you can end up with toxins in your body.

One that is often overlooked is contact with the skin. Now, I know most of you are thinking that it’s obvious you should wear gloves while working with herbicides, but you don’t only have skin on your hands, do you? Areas on the head such as the ears and the scalp are actually just as absorptive as the hands, as are your ‘nether regions’ so wiping sweat from your head with your forearm, or not thoroughly washing your hands and arms before going to the toilet, can all result in toxins getting into your system.

Inhalation is another thing to be aware of, and some chemicals are more dangerous than others when it comes to breathing them in. I remember many years back, before I knew better, getting a pounding headache from using a moss killer with only a rag covering my mouth and not proper protective equipment. Looks like this guy did the same thing-

Using proper protective clothing and equipment

As you can see from above, there are plenty of ways that using a weed killer can cause you harm, and that’s why it is really important to wear the correct protective equipment, and also the right kind of clothing.

As absorption through the skin is a major issue, don’t go out there in shorts, t-shirt, and flip-flops, and expect that you’ll be ok. You need to be properly covered up and wear long sleeves, trousers or jeans, and a pair of work boots or wellies. Trainers can actually absorb the chemicals and then you can unknowingly walk them over to areas where you don’t want them.

You definitely need a good pair of safety goggles as the weed killer can be blown by the wind while you are spraying, or you can accidentally splash it in your face while mixing or handling it. A full plastic face shield is also a good addition, but don’t think that this means you don’t need to wear a mask, as you still need protection from inhalation.

Gloves are another essential piece of equipment but don’t just think any old gardening gloves will protect you, as they won’t. What you need are gloves that are actually tested and certified to resist chemicals, and it’s worth paying a little extra for a really good pair.

One thing that people forget is that you really need to keep your gloves on when you wash your hands after you have finished handling weed killers. This ensures that you clean all of the product off the gloves before you remove them, preventing your skin from getting contaminated.

Make sure you know the re-entry times

After applying a weed killer to an area, there will be a certain amount of time that you will have to wait before it is safe to let your kids and pets around there. Some modern products say that they are safe as soon as they dry, and while I don’t believe they are trying to mislead, I always prefer to be cautious with weed killers, or any other toxic chemical for that matter, and so I usually wait 24 hours before re-entering that area, especially if it is for something like cooking a BBQ or relaxing on a sun lounger where a lot of my skin is exposed.

How to protect your lawn

Grass is quite hardy and will usually recover soon enough if you have been a little less than careful with your watering can or sprayer that is filled with weed killer. However, there are some times when your lawn is more likely to suffer permanent damage, and those times are-

-When your grass is younger than five months old. If you have recently overseeded patches on your lawn or laid a new lawn, the young grass might not be able to handle the toxins in your weed killer as well as mature grass can, so it’s best to avoid using these kinds of products until 6 months have passed to be on the safe side.

– When there has been a spell of very hot and dry weather. At these times, your lawn will absorb more of the chemical and this can cause some serious damage.

– When it is very windy. The wind will blow particles of weed killer into unwanted places, and as your lawn is probably the largest green area in your garden, it is usually the place that suffers the most.

If you follow these tips, you should be much safer when using weed killer in the future and can avoid harming your lawn, flower beds, and much more. Even when using organic weed killers, you should still be very careful about handling them and wear protective equipment and proper clothing.

There are other alternatives to using weed killers, such as weeding tools, weed burners, and weed membranes, and if you have weed problems on your patio, you might want to look into sealing the gaps to prevent them from growing through instead of using a chemical.

About Terry Smith

I’m Terry Smith from, a professional landscape designer, hobbyist gardener, and barbecue fanatic with 20 years experience building and restoring. So as you go through my site you'll watch me document some of the professional garden installs I make as well as the major projects I take on at home. While sharing those experiences and guiding you, I'll be recommending some great tools I use to enable this along the way so you can really buy in confidence. Always feel free to pop me a message:

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