A Gorgeous Purple Perennial Brings Autumn Blooms But Packs A Downside

With its eye-catching blooms, autumn crocus (Colchicum autumnale) stands out as a perennial that brings timeless beauty to your garden. Blink and you might miss it emerging from the ground without any leaves, creating the illusion it appeared out of nowhere. While it brings a magical touch to gardens as autumn sets in, there's a serious downside: The plant is highly toxic. It shows that even the most striking flowers can hide a dangerous side.

Every part of the autumn crocus is poisonous, though the seeds and flowers pack the strongest punch. The underground corms may be less concentrated, but they're still large enough to cause serious harm. The danger comes from a chemical called colchicine, which disrupts how cells function and spreads its effects through the whole body. People, pets, and wildlife are all at risk, and poisoning can quickly turn severe. It only takes a tiny amount to be lethal, making this plant one to admire from a distance.

Native to central and Southeastern Europe, this easy-to-grow flower isn't a true crocus despite its common name. It sends up long, slender stems in late summer to early fall, each topped with star-shaped blooms in shades of lavender, pink, or white. The flowers appear singly or in small clusters, rising from the ground without any leaves, which is why the plant earned the nickname "naked ladies." In spite of its poisonous ways, it has an upside: a favorite stop for powerhouse pollinators like bees and butterflies. Still, use caution to avoid potentially lethal incidents.

Autumn crocus loves soaking up the sun; six hours or more is ideal, but it'll also do fine with a bit of partial shade. It's not picky about soil, happily growing in clay, loam, or sandy spots, as long as the ground drains well. The plant does best in slightly acidic to neutral soil, though it can tolerate a touch of alkalinity. Hardy across USDA Zones 4 through 9, this perennial reaches about 6 inches tall and spreads 10 to 12 inches wide; once it's established, this is a perennial that will bloom every autumn. 

You can plant it in front of shrubs, tuck it among low-growing perennials, let it drift through a meadow, edge a woodland, or brighten up patios and walkways. Plant the corms roughly 7 inches deep and 4 inches apart in early fall, and when they go dormant, separate the corms to multiply your plants for future seasons. Let the leaves die back on their own before trimming, since they're busy storing energy for next year's blooms. This plant also multiplies naturally, forming small baby corms alongside the main one. Dig up dormant clumps in summer to separate the little corms and give them space to grow. Every few years, dividing crowded corms helps keep air flowing and reduces the risk of fungal problems. It's generally trouble-free, and it's among the best flowering plants for your garden that are deer-resistant, though slugs might occasionally nibble.