No matter how much time and effort you put into maintaining the garden, a time will come when you’ll need to deal with weed control and it is no different in a family garden, in fact, if you are like me that your family’s safety is paramount above all else. In my house it isn’t just the kids I worry about by Alvin our dog as pets are important to take into consideration too.
Weeds are uninvited plants that grow where they’re not wanted. They’re not particularly fussy about where they grow. Weeds are as likely to appear on the lawn and in flower beds as in-between paving slabs.
Like all plants, weeds take nutrients from the soil. However, in the case of weeds, these nutrients are stolen from desirable plants in the garden. One of the most popular and highly effective ways to rid the garden of weeds is to use weed killer.
Find out more in this blog on the best weed killers.
What are Weed Killers?
Weeds can get removed by hand, but this is long, arduous work that isn’t always particularly effective. Every part of the weed needs to be cleanly removed for it not to come back. And it isn’t easy to eliminate weeds completely, including the whole root and all weed seeds, when doing it by hand. For this reason, many gardeners choose to use a weed killer to help get rid of unwanted plants.
Weed killers are chemical-based solutions designed to kill weeds. Some target specific types of plants, while others destroy any plant they come into contact with.
How to Choose the Best Weed Killer for You
Choosing a weed killer can be tricky if you don’t know where to start. Therefore, the first thing to consider is the location of the garden weeds – you probably don’t want to use the same type of weed killer for lawn weeds and those that grow between paving slabs.
Next, consider the type of weed you want to eradicate. Generally speaking, broadleaf weeds and grass weeds are different types that require slightly different treatments.
Selective Herbicides vs Non-Selective Herbicides
Selective Weed Killers
Selective weed killers target specific types of plants, leaving desirable plants unscathed. Most lawn weed killers are selective and will kill weeds like dandelions and clover, leaving the grass around them healthy.
Non-Selective Weed Killers
Non-selective weed killers do not discriminate between plants and will kill almost any plant they come into contact with. While this makes them stronger and quicker to act, it does mean they’re not suitable for areas containing other plants. This type of weed killer is most often used for paved areas and driveways, where it doesn’t matter if the soil gets contaminated.
Contact Herbicides vs Systemic Herbicides
Contact Weed Killers
Contact weed killers work by touch. This type of herbicide enters the weed’s system and travels through it to kill the entire plant. They work best when used in the daytime during the growing season and don’t have any detrimental impact on the soil underneath.
Systemic Weed Killers
Systemic herbicides are sprayed on foliage and work their way through the weed to kill the root systems, eradicating the weed entirely. This type of weed killer doesn’t work as quickly but is effective, killing unwanted weeds from the inside out.
Post-Emergence Herbicides vs Pre-Emergence Herbicides
Post-Emergent Weed Killers
Post-emergent weed killers are used for killing mature weeds and plants. After application, the weed shrivels and often turns brown. Post-emergent herbicides work best on young weeds that haven’t yet spread their seeds.
Pre-Emergent Weed Killers
Pre-emergent herbicides are designed to kill very young weeds, preventing them from reaching maturity. The seedlings are killed, so the plant doesn’t emerge through the ground.
What Are the Most Common Types of Weed Killers?
The most common type of weed killer used by home gardeners in the UK is a systemic herbicide. Brands such as Roundup and Resolva are non-selective systemic weed killers containing the active ingredient glyphosate.
Glyphosate works by preventing plants from producing a specific enzyme, without which they cannot grow. As most plants contain this enzyme, glyphosate kills almost any plant it is sprayed on.
When to Use Weed Killers
Herbicides can be used at any time of year. However, they are most effective in spring and autumn, when the plants are actively growing. Pre-emergence weed killers work best when applied in autumn, killing seedlings before they have a chance to sprout in spring.
Weed killers can be much less effective in wet weather. On a windy day, there is a risk that the herbicide will get blown onto other plants that you want to keep. Therefore, the weed killer will be more effective and less likely to destroy favourite plants when it is applied on a dry, still day.
What Happens to Weeds After Spraying?
When you spray weed killer, you halt plant growth, and the weed begins to die. The weed killer works its way through the plant, killing the weed as it goes.
Let the weed killer work throughout the plant before pulling the dead weed from the ground. If you pull it up too early, there is a risk that some of the roots will be left behind and be able to grow again. Plants sprayed with weed killer are generally easy to pull, particularly those with shallow roots.
Avoid placing dead weeds in your garden waste or compost bin, as they can harbour diseases that will affect your wanted plants. Instead, bag them up and put them in the general waste bin.
How Long Does It Take Weed Killer to Work on Garden Plants?
Each type of weed killer has its own chemical structure and kills plant life at a different rate. Likewise, different types of weeds are quicker and easier to kill than others.
Often, noticeable signs of the weed killer taking effect will appear within a couple of days. For example, plants in the treated area may start to turn yellow or shrivel up. However, it can take weeks for the herbicide to spread through the whole plant and for weeds to be killed completely.
Slow-acting herbicides are usually more effective in the long term as they work hard to stop weeds from coming back. On the other hand, fast-acting weed killers have quicker results but are likely to need to reapply more often.
Weed killer is a useful tool for better weed control and is the easiest and quickest way to limit weed growth in the garden. Apply weed killer carefully, taking care not to target desirable plants. Always read the label and instructions to give the weed killer the best chance at working, and to ensure the herbicide is used safely.
Not everyone will choose to use a weedkiller and personally, when we were growing vegetables to eat as a family we used natural weed killers such as vinegar, salt (to prevent slugs) diluted soap in a spray bottle to spray on leaves and we heard about using a mix of acetic acid and alcohol on really hard to kill weeds.