Spiny Amaranth: The Prickly Garden Visitor You Didn’t Invite
If you’ve ever been weeding your garden and encountered a sturdy, spiny plant that seems determined to stick around, you might have met Amaranthus spinosus, commonly known as spiny amaranth or spiny pigweed. This annual forb has a knack for showing up uninvited in gardens across much of North America, and while it’s not necessarily a villain, it’s probably not the guest you were hoping for either.
What Exactly Is Spiny Amaranth?
Spiny amaranth is an annual herbaceous plant that belongs to the amaranth family. True to its name, this plant comes armed with sharp spines along its stems, making it less than pleasant to handle without gloves. As a forb, it lacks significant woody tissue and completes its entire life cycle within a single growing season.
The plant produces small, inconspicuous greenish flowers that cluster together in dense, somewhat unremarkable inflorescences. While some amaranths are prized for their colorful foliage or edible seeds, spiny amaranth is generally considered more of a utilitarian survivor than a garden beauty.
Where You’ll Find It
Spiny amaranth has quite the travel resume. It’s native to the lower 48 United States, Puerto Rico, and the U.S. Virgin Islands, but has also established itself as a non-native species in Canada, Hawaii, and other Pacific regions. You can encounter it across a vast range of states and territories, from Alabama to Wisconsin, and from California to Maine.
The Spiny Amaranth Experience in Your Garden
This plant has a particular fondness for disturbed soils and sunny locations, which unfortunately describes many garden beds perfectly. Its facultative upland status means it typically prefers non-wetland areas but can tolerate some moisture variation, making it adaptable to various garden conditions.
Here’s what you can expect if spiny amaranth decides to call your garden home:
- Fast growth in warm weather
- Tolerance for drought and poor soils
- Wind-pollinated flowers that don’t attract beneficial pollinators
- Sharp spines that make handling unpleasant
- Prolific seed production if allowed to mature
Should You Grow Spiny Amaranth?
The short answer is: probably not intentionally. While spiny amaranth isn’t listed as invasive or noxious, it’s not typically chosen for ornamental purposes. Its weedy growth habit, spiny stems, and unremarkable flowers make it a poor choice for intentional cultivation in most garden settings.
However, if you’re interested in the amaranth family for your garden, there are much better native alternatives to consider:
- Red amaranth (Amaranthus cruentus) for dramatic foliage
- Love-lies-bleeding (Amaranthus caudatus) for unique drooping flower clusters
- Green amaranth (Amaranthus viridis) for edible leaves
Dealing with Uninvited Spiny Amaranth
If spiny amaranth shows up in your garden uninvited (which is more likely), here’s how to handle it:
- Wear thick gloves when removing it to avoid the spines
- Pull young plants before they develop extensive root systems
- Remove plants before they flower and set seed to prevent spread
- Maintain healthy soil and established plantings to reduce available space for weedy growth
- Consider it compostable if removed before seed production
The Bottom Line
Spiny amaranth is one of those plants that’s perfectly fine existing in the world but probably doesn’t deserve a place in your carefully planned garden. It’s a tough, adaptable annual that can handle challenging conditions, but its spiny nature and weedy appearance make it more of a maintenance issue than a garden asset.
If you encounter it in your garden, don’t panic – it’s not going to take over your entire landscape. Simply remove it when you see it, and focus your planting efforts on more garden-worthy native species that will provide better aesthetic appeal and wildlife benefits. Your garden (and your hands) will thank you for it.
