Invasive Tall Weeds With Yellow Flowers [What to Do]

Bright yellow flowers are lovely, right? Well, until they’re attached to invasive tall weeds, that is.

Perhaps the weeds fly under your radar at first until they grow tall and thick. Then, you realize you have invasive weeds. 

The problem is, by that point, they’ve already dominated your residential or commercial property lawn.

Fortunately, you can take back your yard with the great advice our team at SunCo has for you here today. 

The Problem With Tall Weeds With Flowers 

Here are some of the risks you contend with if you leave these tall weeds to take over: 

Ugly Lawn 

Your lawn will look less appealing once weeds dominate it.

Your landscaping efforts will barely stand out, and the flowers you tended to last season will get lost amongst the sea of tall weeds with yellow blooms. 

It doesn’t matter whether yours is a commercial or residential lawn; weeds detract from it either way. 

Less Room and Resources for Healthy Plants

Have you ever wondered why weeds grow so much faster than other plants and flowers on your lawn? It’s because they hog resources.

As they take up larger patches of your lawn, they push out healthy grasses, plants, and flowers. They also use all the nutrients in the soil and the sunlight that other plants need to thrive. 

Harder to Remove

If you’re still unconvinced, this ought to change your mind. The more the weeds grow unencumbered, the harder they are to control.

Their root systems grow larger, which means you can’t remove them by hand. Pre-emergent herbicides won’t do much either. 

Identifying Invasive Tall Weeds Growing Yellow Flowers 

Not all tall weeds that grow light yellow flowers look identical. Some of them are even appealing. However, they’re all weeds, and so they have to go.

The following table breaks down these common yellow-flowered weeds, including how big they get and when they usually grow.

Weed Name	Weed Size	Growing Season
Yellow Salsify	3 feet	Late spring to early summer
Yellow Rocket	3 feet	Winter
Yellow Nutsedge	2.5 feet	Late spring to early summer
Wild Radish	Up to 4 feet	Spring to fall
Wild Parsnip	Up to 5 feet	Spring to summer
Marsh Yellowcress	3 feet	Summer to winter
Creeping St. John’s-Wort	Up to 3 feet	Summer
Common Evening Primrose	6 feet	Summer to fall
Common Ragwort	Up to 3 feet	Summer to late fall
Canada Goldenrod	4 to 5 feet	Late summer into fall

It’s worth noting that many of these weeds, especially those with pale yellow flowers, belong to the mustard family. 

We recommend carefully assessing the potential weed and its flower head. You don’t have to touch it, but look at it and what it’s surrounded by.

Do you recall planting anything that could grow small yellow flowers in that area? If the answer is no, then you may have weeds.

Bear in mind that weeds can spread fast, so even if you did plant flowers in one section of your yard or commercial property, they could still appear all over if you’re contending with one of the above invasive weed species. 

Another solution you can use to confirm weeds is plant identification apps. Since weeds are technically plants, any app that requires a photo should be able to tell you whether yours is a weed or plant. 

Of course, you can always rely on the experts at SunCo to identify weeds for residential and commercial properties.

Once we identify your weed problem, we can recommend remediation and lawn maintenance strategies for healthier, more appealing landscaping. 

Weed Removal Options to Explore 

You’ve confirmed your property has invasive, flowering weeds and not enough woody plants.

This news can throw you into a panic, so here is a friendly reminder that these methods won’t work against weeds:

• Ignoring them (they will continue growing). 
• Segregating them from the rest of your garden with mulch or chicken wire (the weeds will just grow around it). 
• Mowing your lawn in the hopes of killing the weeds (any rhizomes or roots below ground will survive, allowing the weed to regrow).
• Trimming the weeds (the same reason as above applies).

Okay, so now that you know what not to do, let’s offer some practical advice on how you can remove noxious weeds.

Remove Them by Hand

If you want to start with the least expensive option, that’s none other than manual removal.

Be advised, though, that what you save in money, you more than makeup for in sweat equity. Manual removal is hard work. 

Here at SunCo, we don’t want to waste your time, so we’ll tell it to you straight.

It’s not worth your time to manually remove weeds if broadleaf flowering weeds have taken over your landscaping. Some examples of broadleaf flowering weeds are dandelions and creeping cinquefoil. 

Why shouldn’t you remove them by hand? These weeds are notoriously tough to pull. You’ll go through lots of time and trouble and not have a lot to show for it. 

We also suggest moving on to another method if you have a large weed infestation. It’s just not worth the effort.

There’s an art to pulling weeds. You need to grip the weed as near to the ground as you can, then yank upward.

It helps to dig around the soil a bit before you pull so the soil is looser and more pliable. You must remove the entire root system. 

Use Herbicide

Many more people would rather jump right to the herbicide, and rightfully so. 

Depending on the formula, herbicides can wreak all sorts of havoc on yellow-flowered weeds, whether it’s stopping seedlings from germinating, invading the plant with faux hormones, limiting its ability to make amino acids, stopping photosynthesis, or inhibiting cell division. 

Weed herbicides are either pre- or post-emergent. Pre-emergent herbicide goes on weeds before they sprout.

It’s an excellent preventative, but it requires you to be diligent.

For starters, you have to know the type of weeds you’re contending with, such as a perennial plant or an annual weed. Then, you have to know when it grows and its lifecycle to time your application correctly.

If your issue with weeds is already too far gone for pre-emergent herbicide, then you’d reach for post-emergent herbicide instead. This formula is intended for weeds after they’ve grown. You can kill them on contact.

Weed killer, being a chemical, requires you to be careful when using it on dandelion seeds and more. Here’s what we recommend:

• Always follow product usage instructions on the packaging to the letter regarding how much to apply, when, and where. 
• Do not apply herbicide near other healthy plants, as you will kill them. 
• Wait for a calm day to use herbicide, as the wind can carry it to nearby plants and flowers. 

Apply Mulch

You can only use mulch if you’ve already curtailed your weed problem. That’s why we mentioned above that mulching alone cannot stop weeds.

However, it’s valuable for inhibiting their future growth. 

Mulch covers the soil, limiting how much sunlight can get in. Although most invasive plant species grow lightning-fast and insidiously, they still need sunlight to thrive.

If they don’t get enough of it, they can’t grow as fast and spread as far. 

Besides that perk, mulch is a fantastic addition to almost any landscaping setup. It’s great for separating parts of your garden or keeping plants divided.

You can make your own mulch using ingredients like grass clippings, pine needles, old newspaper, wood chips, straw, and chopped bark.

SunCo also provides mulch in several appealing, varied colors to suit any residential or commercial property. 

Call on the Professionals

Invasive weeds can leave you ready to tear your hair out.

The tall weeds gently bob in the breeze outside, the flowers waving. They’re almost taunting you. You’ve tried killing them, but it’s not working. 

In those situations, you should consider relying on the assistance of the pros at SunCo.

We understand how frustrating weeds can be and how much they take away from an otherwise beautiful landscaped property. 

We’re ready to help you get to the bottom of your weed problem and put it behind you once and for all. 

Get the Help You Need From the Pros at SunCo

Invasive tall weeds growing yellow flowers may look lovely but looks can be deceiving. They’re still weeds at the end of the day, which means removal should be your top priority.

Whether you decide to remove these weeds by hand or jump straight to the herbicide, you have plenty of solutions for a weed-free lawn.

You can always count on SunCo to help you achieve your dream lawn, whether it’s through our maintenance services or the great advice on our blog.