Arrowhead (Sagittaria sagittifolia): A Beautiful but Problematic Water Plant
If you’ve been browsing water plants for your pond or bog garden, you might have come across the striking arrowhead plant. With its distinctive arrow-shaped leaves and delicate white flowers, Sagittaria sagittifolia certainly catches the eye. But before you add this aquatic beauty to your shopping cart, there’s something important you need to know.
What is Arrowhead?
Sagittaria sagittifolia, commonly known as arrowhead, is an herbaceous perennial that belongs to the forb family. This means it’s a vascular plant without significant woody tissue, with its growing points located at or below ground level. The plant gets its common name from its distinctive arrow-shaped leaves that emerge above the water surface.
During summer, arrowhead produces attractive white flowers with three petals arranged in whorls along tall stalks, creating a lovely display that attracts bees and other pollinators.
Where Does Arrowhead Come From?
Here’s where things get complicated. Sagittaria sagittifolia is native to Europe and Asia, not North America. While it may look similar to our native arrowhead species, this particular plant is actually an introduced species that has caused significant ecological problems.
The Problem: It’s Invasive and Noxious
Warning: Before you consider planting arrowhead, you need to know that Sagittaria sagittifolia is classified as a noxious weed in the United States and is specifically prohibited in Wisconsin. This isn’t just bureaucratic red tape – these classifications exist because this plant can seriously harm our native ecosystems.
When non-native arrowhead escapes cultivation (and it often does), it can:
- Outcompete native aquatic plants
- Alter water chemistry and flow patterns
- Reduce habitat quality for native wildlife
- Form dense monocultures that are difficult to remove
Why You Shouldn’t Plant It
While Sagittaria sagittifolia might seem perfect for your water garden – thriving in full sun to partial shade, hardy in USDA zones 5-10, and requiring only shallow water or consistently wet soil – the environmental risks far outweigh any aesthetic benefits.
The plant’s vigorous growth habit and ability to spread through both seeds and underground tubers means it can quickly escape your garden and establish in nearby natural water bodies. Once there, it’s incredibly difficult and expensive to remove.
Better Native Alternatives
The good news? North America has its own beautiful native arrowhead species that provide the same visual appeal without the ecological risks:
- Sagittaria latifolia (Broadleaf Arrowhead): Features similar arrow-shaped leaves and white flowers
- Sagittaria rigida (Sessile-fruited Arrowhead): Offers a more compact form perfect for smaller water features
- Sagittaria australis (Longbeak Arrowhead): Provides excellent wildlife habitat and food sources
These native alternatives will give you the same stunning arrow-shaped foliage and delicate white blooms while supporting local ecosystems and providing food and habitat for native wildlife.
The Bottom Line
As tempting as it might be to add Sagittaria sagittifolia to your water garden, this is one plant that’s best left at the nursery. Its invasive nature and noxious weed status make it a poor choice for responsible gardeners who care about protecting our native ecosystems.
Instead, choose one of our gorgeous native arrowhead species. You’ll get the same beautiful look while supporting local wildlife and avoiding potential legal issues. Your local ecosystem (and your neighbors) will thank you!
