Scottsdale’s unique desert ecosystem is home to a stunning variety of native plants, from towering saguaros to delicate desert wildflowers. But the spread of invasive plant species threatens to disrupt this balance, crowding out native plants, increasing wildfire risk, and consuming valuable water resources.
If you’re a homeowner or contractor working on a landscape in Scottsdale, it’s critical to recognize these problem species and take action to remove them. In this guide, we’ll define what makes a plant invasive, identify the most problematic species, and offer effective removal strategies to protect Scottsdale’s environment.
What Is an Invasive Plant?
An invasive plant is a non-native species that aggressively spreads and outcompetes native vegetation, disrupting ecosystems, increasing fire hazards, and consuming excessive water. Unlike native plants, invasives lack natural predators or environmental limitations, allowing them to grow unchecked and dominate landscapes.
Why Are Invasive Plants a Problem?
- Disrupt Native Ecosystems – They outcompete native plants for resources, reducing biodiversity.
- Increase Wildfire Risk – Many invasive grasses ignite easily and burn rapidly, fueling dangerous wildfires.
- Consume Excessive Water – Non-native plants can deplete groundwater, putting stress on local water supplies.
- Reduce Property Value – Overgrown invasives overtake landscapes, making yards harder to maintain.
Official List of Scottsdale’s Invasive Plants: Scottsdale Invasive Weeds Poster (PDF)
Common Invasive Plants in Scottsdale
Here are the most problematic invasive species in the Scottsdale area—plants that should be removed and replaced with more sustainable, fire-safe alternatives.
Fountain Grass (Pennisetum setaceum)
- What It Looks Like:
- Perennial bunchgrass growing up to 3 feet tall.
- Slender green leaves with purple to white feathery spikes.
Why It’s a Problem:
- Highly flammable – This grass spreads fires rapidly through dry landscapes.
- Aggressively outcompetes native plants, reducing biodiversity.
- Commonly sold as an ornamental plant, contributing to its spread.
How to Remove It:
- Manually pull young plants before they spread seeds.
- Mow and bag seed heads to prevent further spread.
- Replace with native grasses like Purple Threeawn or Arizona Cotton Top.
City of Scottsdale Fire Prevention Guide: Wildfire Safety & Invasive Plant Removal
Buffelgrass (Pennisetum ciliare)
- What It Looks Like:
- Dense, clumping bunchgrass growing up to 4 feet tall.
- Light green leaves; bristly flower heads turn golden-brown when dry.
Why It’s a Problem:
- Burns while still green, creating fast-moving, high-intensity fires.
- Displaces native plants, reducing natural food sources for wildlife.
How to Remove It:
- Pull by hand (small patches) or use herbicides (large infestations).
- Monitor for regrowth, as buffelgrass spreads through underground roots.
- Never mow dry buffelgrass—it increases fire risk.
Arizona Invasive Plant Information: Buffelgrass Guide
Stinknet (Oncosiphon piluliferum)
- What It Looks Like:
- Short, bushy plant growing up to 2 feet tall.
- Small, globe-shaped yellow flowers with a strong, unpleasant odor.
Why It’s a Problem:
- Spreads aggressively, choking out native wildflowers.
- Dries out quickly and ignites easily, contributing to wildfires.
- Highly allergenic, causing respiratory irritation.
How to Remove It:
- Pull by hand (wear gloves; it causes skin irritation).
- Remove before it sets seed to prevent spread.
- Use pre-emergent herbicides to prevent regrowth.
Scottsdale Fire Department Weed Control Guide: Invasive Weeds & Wildfire Safety
Red Bromegrass (Bromus rubens)
- What It Looks Like:
- Annual grass growing 10-18 inches tall.
- Brush-like seed heads that turn reddish-purple, then brown when dry.
Why It’s a Problem:
- Highly flammable, acting as wildfire kindling.
- Crowds out native desert grasses that provide food for wildlife.
How to Remove It:
- Remove before it seeds (spring is best).
- Pull by hand or mow small patches.
- Encourage native grass growth to reduce re-establishment.
Desert Broom (Baccharis sarothroides)
- What It Looks Like:
- Evergreen shrub growing 6-12 feet tall.
- Small greenish flowers turn into fluffy white seed clusters.
Why It’s a Problem:
- Spreads aggressively, especially in disturbed areas like roadsides.
- Produces millions of wind-blown seeds, making it hard to control.
- Highly flammable, contributing to fire danger.
How to Remove It:
- Pull seedlings while young before they establish deep roots.
- Cut mature plants close to the ground and treat with herbicide.
- Replace with native shrubs like Jojoba or Creosote Bush.
How to Prevent the Spread of Invasive Plants
- Remove invasives before they go to seed—don’t let them spread.
- Choose native plants whenever landscaping a new home or yard.
- Check for invasive seeds in commercial soil and mulch.
- Avoid planting ornamental invasives like Fountain Grass, even if nurseries sell them.
- Report infestations to the City of Scottsdale or local conservation groups.
Official Scottsdale Fire Department Wildfire Prevention Guide: Wildfire Prevention & Invasive Plants
Final Thoughts: Protecting Scottsdale’s Native Landscape
By removing invasive plants and choosing desert-friendly alternatives, homeowners and contractors play a crucial role in preserving Scottsdale’s natural beauty. Invasive plants may seem harmless at first, but left unchecked, they threaten the ecosystem, increase fire danger, and drain precious water resources.
Need Help Managing Invasive Plants?
If you’re unsure how to tackle invasive species in your landscape, reach out for expert guidance on native plant alternatives and sustainable landscape design.
Let’s work together to keep Scottsdale’s desert healthy and beautiful!
