Alkaliweed (Cressa): A Hardy Desert Ground Cover for Water-Wise Gardens
Meet alkaliweed, a tough little perennial that’s perfectly at home in some of the harshest growing conditions imaginable. This unassuming desert dweller might not win any beauty contests, but what it lacks in flashy flowers, it makes up for in pure resilience and practical garden value.
What Is Alkaliweed?
Alkaliweed (Cressa) is a low-growing perennial herb that forms dense, mat-like patches across the ground. As a forb, it’s a non-woody plant that dies back to ground level each year, then resurges from its root system when conditions are right. Don’t expect towering heights from this ground-hugger – it stays close to the earth, spreading outward rather than upward.
Where Does Alkaliweed Grow?
This hardy plant calls the American Southwest home, naturally occurring across Arizona, California, Nevada, New Mexico, Oklahoma, Oregon, Texas, and Utah. It has also established itself in Hawaii, where it grows as an introduced species that reproduces on its own in the wild.
What Does Alkaliweed Look Like?
Alkaliweed won’t stop traffic with its appearance, but it has a subtle charm. The plant produces small, succulent-like leaves and tiny white to pinkish flowers that appear throughout the growing season. Its greatest visual impact comes from its ability to form dense, carpet-like coverage across the ground, creating a living mulch effect in desert landscapes.
Why Grow Alkaliweed in Your Garden?
If you’re dealing with challenging growing conditions, alkaliweed might be your new best friend. Here’s why gardeners choose this tough little plant:
- Extremely drought tolerant once established
- Thrives in alkaline and saline soils where other plants struggle
- Provides excellent erosion control on slopes and disturbed areas
- Requires virtually no maintenance
- Attracts small native pollinators with its tiny flowers
- Perfect for xeriscaping and water-wise garden designs
Where Alkaliweed Fits in Your Landscape
Think of alkaliweed as nature’s answer to difficult sites. It excels in rock gardens, desert landscapes, and xerophytic garden designs where water conservation is a priority. Use it as a ground cover in areas where grass won’t grow, or let it naturalize in wild garden spaces. It’s particularly valuable for erosion control on slopes or in areas with poor, alkaline soil.
Growing Conditions and Care
Alkaliweed is wonderfully low-maintenance, but it does have specific preferences:
- Sunlight: Full sun is essential for best growth
- Soil: Prefers alkaline, well-draining soils; tolerates saline conditions
- Water: Drought tolerant once established; avoid overwatering
- Climate zones: USDA zones 8-11
- Spacing: Allow room for spreading as it forms colonies
Planting and Establishment Tips
Getting alkaliweed started is straightforward, but patience is key. Plant in spring after the last frost, choosing a sunny location with well-draining soil. While it tolerates poor soils, avoid heavy clay or constantly moist conditions. Water moderately during the first growing season to help establish roots, then step back and let nature take over.
Once established, alkaliweed requires minimal intervention. It may spread by underground runners, gradually expanding its territory – perfect for naturalized areas but something to monitor in more formal garden settings.
Things to Consider
While alkaliweed is native to much of the southwestern United States, gardeners in other regions should consider whether local native alternatives might better serve their landscape goals and support regional ecosystems. In areas where alkaliweed isn’t native, consulting with local native plant societies can help identify indigenous ground covers with similar drought tolerance and low-maintenance characteristics.
The plant’s spreading habit means it’s best suited for areas where you want naturalized coverage rather than precise, contained plantings.
The Bottom Line
Alkaliweed earns its place in water-wise gardens through sheer determination and practicality. If you’re gardening in arid conditions, dealing with alkaline soils, or simply want a ground cover that thrives on neglect, this humble desert dweller deserves consideration. It may not be the showiest plant in your garden, but it might just be one of the most reliable.
