Weed killers, also known as herbicides, are a category of pesticides designed to chemically wipe out the pesky, unwanted weeds and plants growing in whatever agricultural environment you’re working with.
With such a large selection of weed killers available on the market, you’ll have no problem finding the right one for the specific weed problem you want to solve.
However, for the most successful results, it’s important to keep track of when your weed killer expires, and how best to store the product.
This article will get to the bottom of some of the uncertainty surrounding the question of whether or not weed killer expires, and how you can get the most out of your product through proper storage.
Does weed killer expire?
The majority of pesticides, of which herbicides are included, generally tend to be quite stable, meaning they can possess a decently prolonged shelf life. If they are stored in the right way, herbicides can have a shelf life of at least two years.
If the expiration date is not available on the label of your weed killer, however, it is recommended to get rid of the product at the two-year mark.
It’s important to consider the expiration date on the label of your product or the suggested two year limit for two main reasons.
First of all, expired weed killer will likely have degenerated, meaning it will have lost the chemical potency to successfully destroy your weeds. You’ll be stuck with a product that is no longer effective.
Second of all, using expired weed killer also runs the risk of spreading toxins among your plants, consequently damaging them.
How to check if your weedkiller is expired
If your weed killer product does not contain an expiration label and you are unsure of how long you’ve had it, the following are some telling signs that your product is no longer usable:
- You will notice clumping in weed killers in the form of powders, dust, and grains
- The ingredients in a liquid weed killer product will separate
- Oil spray weed killers will be caked in sludge
- The spouts of aerosol weed killers will be clogged
How to preserve weed killer
Your best chance at guaranteeing a longer shelf life for your weed killer is to store it properly. The following is a list of the best recommendations for properly storing and keeping your herbicides:
- Herbicides should be kept in a dry area.
- Herbicide containers should be securely closed when not in use.
- Herbicides should not be in contact with direct sunlight.
- Herbicides should be stored in a location unaffected by extremes of either cold or hot temperatures. The recommended storage temperature for most pesticides is between 5℃ and 40℃. Any temperature outside of this range may damage the product.
- Liquid herbicides should not be kept in areas with a temperature that may fall under 4℃. If exposed to temperatures under 40℉, the liquid product can freeze over and break the glass canister.
- Herbicides should be marked with the date they were bought in order to keep track of its shelf life.
- Herbicides should ideally be purchased in smaller quantities that will be depleted within a single season.
- Herbicides should be stored in the containers they initially came in.
- Herbicides should not be kept in close proximity to other substances or products. Certain herbicides can be quite volatile and may also pollute other products.
- Product labels should always be assessed for more specific storage information.
Are there different types of weed killers?
It’s helpful to get familiar with the different types of weed killers available so you can determine which one will work best for your specific weed problem.
The two primary categories of herbicides are as follows:
Selective herbicides are developed to destroy a particular type of weed without harming the other plants surrounding it.
When buying a selective herbicide, the packaging will commonly notify you of the weed it takes care of, while also noting the plants that won’t be harmed by it.
For this reason, selective herbicides are helpful when dealing with weeds in a garden you are trying to maintain.
Selective herbicides are also separated into two subcategories: pre-emergent and post-emergent. Pre-emergent herbicides are meant to tackle soil, destroying young weeds before they get the chance to grow any further. Post-emergent herbicides target and infect the leaves of the weed directly.
Non-selective herbicides, in contrast, will target and destroy most plants. They are best used in situations where an entire area must be cleared of weeds.
How to use weed killers safely
First and foremost, it’s helpful to note that buying weed killer doesn’t have to be your first option. Before reaching for your wallet, you can give more natural weed control strategies a shot first.
For example, hoeing, tilling, and digging can be effective methods to remove undesired weeds without having to resort to a chemical spray. If you’re not getting optimal results with natural methods like these, then using weedkiller will be your best bet.
There are several things to consider when trying to figure out how best to use herbicides safely. If you plan to apply a weed killer to your garden, it will be crucial to make sure the plants you don’t want to get rid of will not be affected by the product. The best way to protect your plants is to use a selective herbicide that will only target the particular weed you want to kill.
If you’re not certain of the exact type of weed you’re dealing with, or you’re faced with an infestation, using an herbicide containing glyphosate will be your most effective option. Glyphosate tends to get rid of a large variety of plants.
In this case, you can prevent the product’s contamination of the plants you want to save by wrapping a cardboard ring around the weed before spraying it.
Other tips for how to safely apply herbicides include:
- Do not use product on days with strong wind
- Do not use product if you are in proximity to a body of water
- Do not use product around children or animals
- Do not buy more herbicide than you plan on using and ensure that it is safely stored
Using weed killer can be a highly impactful way to deal with a weed infestation. When using weed killers, it is crucial to know that they do expire.
If your weed killer product does not contain a label indicating the exact expiration date, it is suggested to dispose of the product after two years. The best way to ensure your weed killer has the longest shelf life possible is to make sure you store it properly