A few wild violets can add a charming splash of color to your garden or lawn, but these weeds can spread quickly and dramatically when left unchecked. You can control violets using both chemical and organic measures, but you should know that both methods will require time and dedication.
Use a selective broadleaf killer.
For best results, select an herbicide containing either 2,4-D or Dicamba. One containing Quinclorac may also work well against wild violets.
These herbicides are formulated to kill broadleaf plants, like wild violets, while leaving most grasses unharmed. As such, they can be applied to the wild violets in your lawn without damaging the lawn itself.
You will need enough of your chosen herbicide to fill an herbicide sprayer. Follow the instructions on the label of the product to determine how to safely mix and apply the chemical.
Regardless of the ingredients in the herbicide, you should always check the label to verify that it will only kill broadleaf plants and not thin-leaf plants (like grass). Make sure that the weed killer is formulated to do exactly what you need it to do before you apply it.
Try a spot treatment.
When the problem is relatively minor, you can apply a spot treatment directly to each individual violet.
Buy a spot treatment herbicide in a small spray bottle and follow the label instructions to safely apply enough of the chemical to the base of each flower.
Some of the best herbicides for this use are glyphosate and triclopyr. The former will also kill grass, but the latter will not affect most grass species.
Be careful with area applications of non-selective herbicides.
Only use an area application of non-selective herbicide if there are no other plants you wish to preserve in the area.
As the title suggests, non-selective herbicides do not pick and choose which plants they kill. Everything the chemical touches will suffer and die, including grasses and other flowers.
Glyphosate is an herbicide chemical that is especially effective for use against wild violets and many other plants.
Follow the label instructions carefully and apply the weed killer using an herbicide sprayer.
Add a spreader sticker product to the herbicide.
Spreader-sticker products make herbicides more effective by helping the chemical cling to the surfaces of the plant better.
This is especially helpful when you are trying to control wild violets since the leaves of these plants have a very waxy surface.
Mix the spreader-sticker into the herbicide before you apply the herbicide. Follow the instructions that come with the spreader-sticker product when determining the best way to do this.
Apply herbicides more than once.
Wild violets are very resilient, so you’ll need to apply your chosen herbicide multiple times before the plants die off.
Try applying the herbicide once or twice a week, or as directed in the manufacturer’s instructions.
Note that herbicide treatments are often most effective during the fall since these chemicals have an easier time navigating down to the taproot. During the spring and summer, herbicides tend to cling primarily to the leaf tissue without impacting the root. As a result, the violets grow back.
Dig out established wild violets by the root.
Mature violets have a tendency to break when you pull them, leaving the root behind and making it possible for the flower to regrow. Digging each violet out is a much more effective option.
Use a spade or digging fork and start digging toward the flower from about 1 foot (30 cm) away from the visible center of the plant. This loosens the soil around the plant.
When you can get beneath the weed, use your digging tool to lift the weed from underneath. Get as many root pieces as possible to reduce the likelihood of the violet growing back.
Pull out young wild violets.
Young violets are less likely to break when you pull then, so if digging isn’t an option, pulling might still be worth consideration.
Wear thick leather gardening gloves to protect your hands as you pull the violets.
Plan on pulling the weeds when the soil is moist. If you’re going through a dry spell, moisten the area with a garden hose or watering can before proceeding.
Grasp the main stem of each violet as close to the soil line as possible, then yank the flower straight up.
If the violets are breaking off at the crown when you yank them, insert a kitchen fork or garden fork beneath the root and pry it up as you pull.
Improve soil drainage.
Wild violets tend to thrive in shady, moist soils. If the soil in your garden or lawn does not drain well, taking steps to improve its drainage abilities can help the rest of your vegetation grow while restricting the growth of violets.
You can improve the drainage of heavy soil in your garden by mixing in coarse organic material like sawdust or sand. For clay soils, try mixing in gypsum.
There are multiple ways to improve soil drainage in your yard, but one of the simplest is to use a hollow tine aerator to remove plugs of soil throughout the surface of the lawn. Removing plugs of soil can help loosen the remaining soil, allowing water to flow through and drain more readily.
Keep the lawn mowed and properly cared for.
Weeds like wild violets are less likely to grow in a lawn when the lawn itself is healthy. Mow the grass on a regular basis and take other precautions to ensure optimal growth.
The height requirements for grass varieties can vary based on variety and cultivar, but as a general rule, grass should be kept between 2.5 and 3.5 inches (6.35 and 8.89 cm) in cool weather and 1.5 to 2.5 inches (3.81 to 6.35 cm) in the warm season. Mow your lawn every five days during the growing season.
If you’re currently undergoing a dry spell, water the lawn with a garden hose to prevent it from drying out and dying off.
Consider applying a general purpose lawn fertilizer during the spring or summer to give your grass an added boost.
Thin out tree limbs and similar obstructions.
Prune any unnecessary tree branches and overgrown shrubs. Doing so will make it easier for more light to reach the lawn.
Sunlight strengthens your grass. Grass needs at least four hours of sunlight on a daily basis to survive.
On the other hand, violets do best in light shade and can become weakened in bright sunlight.
Clearing debris out of your lawn or removing any unused sheds can also reduce the amount of shade and help control your violet problem.
Spread mulch in problem areas.
After removing an initial spread of wild violets, cover the area with 2 or 3 inches (5 to 7.6 cm) of wood chip mulch.
Mulch will suffocate most weeds, including violets, making it more difficult for them to grow back as a result.
It should also be easier to remove any violets that do pop up from the loose mulch than it is to remove them from compacted soil.
An application of mulch can be used regardless of whether you removed the initial spread of violets by hand or by chemical.
Note that mulch should only be used when you are trying to control violets in a flower bed. Do not mulch a lawn since doing so can weaken the grass.
Switch to an adapted turfgrass cultivar.
If your lawn is too damaged to save, your best bet might be to dig everything up and sow fresh turf grass seeds in its place
Select a turf grass cultivar that has been adapted for use in your specific region and climate. Such cultivars are more likely to thrive when planted, and a thriving, healthy lawn is less likely to have problems with violets and other weeds.
In areas where grass cannot grow due to lack of sunlight, you can still restrict the growth of violets by planting ground-covers and shrubs that do well in shade.