The best way to get rid of thistles is by uprooting the plants completely, or using a herbicide that contains glyphosate.
It’s important to cover the entire area in order to kill all the thistles. Doing so will ensure that these pesky plants don’t grow back.
How to Spot Thistles in the Lawn
When looking for thistles, look out for spiny leaves that appear in clusters. If you pull them up, they will have a taproot, similar to a carrot.
Thistles are also light purple or yellow in color and have flowers that may look like dandelions with spiny leaves.
How to Remove Thistles in Your Lawn
Once the thistles have been identified, it’s time to start removing them. The most important thing when dealing with thistles is to make sure that you remove weeds from your lawn as quickly as possible.
1. Remove Thistles By Hand
Sometimes, putting on gloves and uprooting thistles by hand is a quick and effective way to get rid of them. If you are dealing with creeping or dwarf thistles, you can uproot them by hand and kill them.
However, many other thistles can easily grow back even if you do your best to remove them completely. Even if you use a weeder tool, some species of thistle will still recover. In that case it’s best to use a weed killer.
2. Use Weed Killer
Herbicides are the most effective way to get rid of thistles. Applying herbicide over your entire lawn can ensure that all plants, including thistles, will be eradicated.
It is important to be thorough when applying weed killing chemicals as any surviving plants could easily spread around the lawn again.
3. Use a Stand-Up Weeder
A stand-up weeder is a tool you can use to pull out thistles and other weeds. This tool lets you pull weeds without bending down or kneeling, which makes it easier for people with back problems.
Stand up weeders are also fast and efficient when dealing with thistles.
4. Cutting Off The Flowerhead
By cutting off the flowerhead of a thistle before it has had a chance to set seed, you can prevent them from spreading throughout your lawn. This should be done when the thistle plants are still in their early stages, as once they have set seed it is much harder to get rid of them.
5. Use a Plastic Sheet to Kill Thistles
The heat generated by a plastic sheet can kill thistles and prevent them from growing back again. After uprooting a patch of thistles, try putting a clear plastic sheet over the spot for a few weeks during sunny weather. This will often do so much damage to the thistles, including their roots, that they never grow back again.
How to Prevent Thistles From Growing in Your Lawn
Once the thistles in your lawn have been removed, you can take proactive steps to ensure that they don’t grow back. Here are some tips for preventing future growth:
1. Fertilize Your Lawn
Regular fertilization of your lawn is essential in helping to prevent thistle growth. Fertilizer should be applied at least once a year, as not doing so can leave room for weeds and other unwanted plants to take over and thrive.
Thistles and other weeds can survive in environments with fewer nutrients, but proper fertilizing will help your grass to grow and fill in any empty spaces to reduce the likelihood of them taking root.
With adequate fertilizer, your lawn will be better equipped to block out thistles and other weeds from invading.
2. Reseed the lawn
One of the best ways to stop thistles from invading your lawn is to reseed grass. When the turf is properly maintained through watering, fertilizing, aeration and other maintenance, this helps crowd out potential thistle growth.
By having lush, healthy grass all over your lawn, there will be no room for thistles to take root and grow.
3. Aerate Your Lawn Regularly
Compacted soil makes it difficult for air, water, and nutrients to reach the ground. This results in poor conditions for grass growth but allows thistles to thrive.
To help prevent this from happening, it is important to aerate your lawn regularly. By doing so, you create an environment that is better suited for grass growth and less conducive for thistle growth.
How to Remove Thistles Without Killing the Grass
Organic weed killers like Captain Jack’s Lawnweed Brew and Adios Organic Weed Killer are effective ways to control thistle without harming your grass or other plants in your lawn. Both products must be applied multiple times during the Spring and Fall to weaken the thistle’s deep root system.
Do Thistles Die in the Winter?
Yes, most species of thistle will die back in the winter, when temperatures drop and light levels decrease. This is why it is a good idea to remove them from your lawn in late autumn or early winter.
This will reduce their numbers and make it easier for you to deal with any remaining ones in the spring.
Thistles can be difficult to remove from lawns, but with the right approach, you can get rid of them without killing all your grass.
The best way to do this is by using herbicides, stand-up weeders, and plastic sheets to kill existing thistles. Then prevent future outbreaks by keeping your grass healthy with fertilizer and aeration.