No matter the season, weeds are always ready to invade your yard. These plants are relentlessly invasive, and some are downright stubborn to get rid of. Once they sneak into your garden, it’s a real headache!
Garden weeds sneakily steal water, sunlight, and soil nutrients from your precious plants. Some even release toxic chemicals into the soil, suppressing the growth of other plants and altering the entire ecosystem. For novice gardeners, nothing is worse than watching your hard work drown in a sea of weeds.
Here’s a lineup of the most invasive weeds you should keep an eye on. With a variety of plant species in the garden, figuring out what’s a weed and what’s not is crucial! If you spot any of these troublemakers spreading in your garden, consider timely removal to stop them in their tracks.
1. Dandelion
We all might cherish childhood memories of blowing dandelion fluff, but the thrill fades when these little troublemakers invade your lawn. Dandelions are essentially stubborn weeds with deep roots, making them a headache to uproot manually. To top it off, they’re prolific seed spreaders, so tackling them early is key.
For the young dandelions, good old hand-pulling does the trick. If they’ve matured and gone to seed, opt for post-emergent weed control or iron-based herbicides for a swift demise within 2-4 days. Regular checks and lawn care routines will help keep their seeds at bay.
2. Crabgrass
Crabgrass, or as some call it, the ‘lawn invader,’ is an annual weed that pops up in late spring. It has sprawling stems that hug the ground, grows rapidly, with long narrow leaves, and tiny, daisy-like white flowers branching out at the top.
Dealing with crabgrass can be a real headache for both farmers and gardeners, as it seems to resist many weed-busting methods.
How to knock it out: Trim your lawn regularly in late summer when crabgrass is seeding to limit its seed production. Alternatively, when you spot the first forsythia blooms, apply a pre-emergent herbicide. Quick tip: Pre-emergent herbicides also prevent grass seeds from sprouting, so avoid using them in areas where you plan to sow grass.
3. Bull Thistle
Bull thistle (Cirsium vulgare) is like the tough guy of plants, armed with spiky defenses. Found in every state in the U.S., this aggressive weed is so unruly that many states have banned it as a noxious weed.
It spreads solely through seeds, and each flower head can produce a whopping 100 to 300 seeds, with each plant boasting 1 to over 400 flower heads! As a non-native plant, once it takes root, it outshines all the local greenery. Wildlife or livestock don’t fancy it.
Come midsummer, those seed heads turn into white fluff and scatter seeds far and wide.
How to take it down: Regular mowing throughout the growing season, as long as it’s not too early, might lend a hand. Best to mow post-seeding but pre-flowering. However, mowing alone won’t stop thistle seeds from blowing in from other areas, so it needs to be combined with treatment. Using an herbicide containing 2,4-D and dicamba offers better control. Opt for spot spraying on individual plants or small patches, rather than blanket spraying across the entire lawn.
4. Field Bindweed
Field bindweed, a weed cousin to the lovely morning glory, is a clinging or creeping perennial. Its seeds can survive in the soil for up to 20 years, and its roots can reach depths of 10 feet.
Even a small piece of the root can sprout into a new plant, making manual pulling not the best option for these invasive plants. Handle existing plants with post-emergent weed killers. Use coverings or pre-emergent herbicides to prevent seed germination.
5.Nightshades
A shrub-like weed with purple bell-shaped flowers. This particular plant is toxic, and poisoning can result in dilated pupils, loss of balance, and may lead to hallucinations and seizures. They often grow alongside gardens and farms, competing with crops.
However, they are relatively easy to control. Give glyphosate-based herbicides like RoundUp or triclopyr-based herbicides a shot.
6. Poison Ivy
Poison Ivy is one of the most notorious invasive plants, being a perennial that can grow in your backyard, not just in the woods. Touching the plant can cause a severe rash and itching.
How to deal with Poison Ivy: You can cut or dig it out from the ground (just make sure to wear gloves and long sleeves to avoid skin contact) and dispose of it with the trash. Alternatively, use any herbicide labeled for Poison Ivy, like glyphosate-based herbicides such as RoundUp, or herbicides based on triclopyr.
7. Violets
Sometimes, ‘weeds’ aren’t really weeds. Wild violets (Viola sororia) fall into that category, mainly appearing in wooded areas and wild gardens. These perennial ‘weeds’ grow easily, so they might start to take over your lawn.
Although wild violets don’t spread through underground root structures, they can freely self-seed, making them seem like invasive plants in your lawn. In this case, you’ll need to manually dig out the rhizomes along with the plants or spot-spray with a broadleaf herbicide containing 2,4-D and mecoprop.
8. Poa Annua
Poa annua is a pesky invader that clusters together, sporting fuzzy seed heads on top. Both annual and perennial grassy seeds easily infest garden beds, pathways, and vacant lots. Controlling this lawn weed requires proper lawn care, involving the right mowing, fertilizing, and watering practices.
If you opt for manual removal, throw on some rubber gloves and spray grassy weed preventatives on the crown and as many leaves as possible to keep it in check.
9. Clover
Clover is a broadleaf weed that can spread through seeds and stems. This weed is often found in poorly nourished and nutrient-lacking lawns – the kind that needs some fertilizer love! But if you’re looking for a beautiful and low-maintenance alternative to a traditional lawn, you might want to keep it.
One of the best ways to prevent this weed is by maintaining a healthy, weed-free lawn through proper lawn care and fertilization programs.
However, if clover has already paid a visit, many effective post-emergent herbicides can lend a hand. You can also try pulling this weed, but be sure to get it all out; otherwise, your efforts might be in vain