Top 5 Invasive Weeds in Phoenix (Best Practices for Year-Round Management)

Top Weeds That Invade Phoenix, AZ

Some weeds are worse than others. They spread fast, compete with healthy plants, and can be tough to get rid of. Here are five of the most common troublemakers in the Phoenix area:

1. Burr Clover (Medicago polymorpha)

Burr Clover is a sneaky invader. It starts as a leafy green plant but quickly produces tiny burrs that stick to clothes, shoes, and pet fur. These burrs carry seeds that spread the plant even more.

• It thrives in lawns and granite areas.
• When it starts growing, it’s hard to stop without proper weed control services.
• The best approach is to apply a pre-emergent herbicide in early spring to stop it before it takes over.

2. Cheeseweed (Malva parviflora)

Don’t let the delicious name fool you; Cheeseweed is a tough weed to control. It has round leaves, grows low to the ground, and spreads quickly.

• It grows in lawns, granite areas, and even sidewalk cracks.
• It has a deep taproot, which makes it hard to pull by hand.
• Prevent it with pre-emergent applications and maintain a good landscape maintenance routine.

3. Oxalis (Oxalis stricta)

Oxalis looks harmless at first. It resembles a clover with small, bright green leaves and yellow flowers. But don’t let it fool you; this weed spreads aggressively, especially in lawns and groundcovers.

• It loves moist soil and shaded areas.
• The seeds can shoot up to 10 feet when disturbed.
• The best way to keep it under control is with pre-emergent herbicide applications in early spring before it has a chance to sprout.

4. London Rocket (Sisymbrium irio)

London Rocket is a fast-growing winter weed that flourishes in disturbed soil, gravel, and roadsides. In Phoenix, it pops up in granite areas and open spaces after the rainy season.

• This weed has long, jagged leaves and grows tall fast.
• It’s a major problem in unmanaged landscapes.
• Again, the best way to prevent it is to apply pre-emergents to block seeds from germinating.

5. Spurge (Euphorbia spp.)

Spurge is a low-growing weed that spreads like wildfire. It has reddish stems and milky sap, which can be irritating to the skin.

• It thrives in hot, dry climates like Phoenix.
• It forms dense mats that choke out lawn alternatives and groundcovers.
• Pre-emergent herbicides in early spring will help stop it before it becomes a problem.

Why Early Spring is the Best Time for Pre-Emergent Herbicides

If you want fewer weeds this summer, now is the time to act. Early spring is the best time to apply pre-emergent herbicides for two key reasons:

1. Warmer Nighttime Temperatures: As Phoenix nights warm up, weed seeds start germinating. A pre-emergent treatment stops them before they sprout.
2. Rain Helps Activate the Herbicide: Spring rain pushes the herbicide into the soil, which makes sure it reaches the weed seeds before they break through the surface.

Titan Landscape Services provides commercial landscape maintenance plans that include weeding services and pre-emergent applications to keep your property weed-free year-round.

More Ways to Keep Weeds Under Control

A concrete driveway, parking lot, or gravel area can still grow weeds if left untreated. Here are a few more ways to stop weeds from spreading:

• Regular Lawn Maintenance: Keeping your grass healthy and thick helps crowd out weeds before they take over.
• Lawn Alternatives & Groundcovers: Replacing grass with lawn alternatives like xeriscape plants or groundcovers reduces the amount of space weeds have to grow.
• Post-Emergent Applications: If weeds have already sprouted, post-emergent herbicides can target them directly. These treatments work best when applied while weeds are actively growing.

• Mechanical Weed Removal: In areas where chemicals aren’t an option, mechanical removal (hand-pulling or using specialized tools) is an effective way to keep weeding services chemical-free. Regular removal prevents weeds from going to seed and spreading further.