how to divide trilliumI DON’T RECALL HOW I FOUND THEM—maybe it was while fixing something, or painting the house all those years ago. But for some reason I was down at ground level, peering under the floor of the front porch, and there they were, in near-darkness: two tiny trillium plants. I rescued them, and you know how it goes when a plant thanks you for your help: Now I have hundreds, thanks to those first two, and to a tip handed down from a great gardener about dividing them when they’re in flower. Yes, like right now.

The books, and most experts, will recommend you wait until around fall, but sometimes trilliums and other ephemerals aren’t so easy to find by then as they are in spring, in their flowering glory (above). This little “aha” was imparted to me and Ken Druse by Evelyn Adams of Wellesley, Massachusetts, when we visited her garden awash in trilliums one spring, working on Ken’s 1994 book “The Natural Habitat Garden.”

“How did you get so many?” Ken asked the elderly Adams, and it was simple, she said: She dug them up and separated them when they were in flower—you know, when you can see just where they all are, since none have gone dormant.

The instruction made such an impression that Ken and I have both been doing it this way—not waiting till late summer or fall—for years. (Wild plants must never be dug for this or any purpose. Commercially, trillium are ethically propagated by seed.) Since their rhizomes are not too far below the soil surface, it’s not hard work to find the mass of tangled roots and rhizomes.

Each division from your garden needs to have at least an eye or growing point, but neither of us cuts them up into tiny bits—in fact, I just gently tease apart the clumps descended from those two native Trillium erectum, or wake-robin, and replant each rhizome. I count 10 divisions in that shovelful, above, each of which will become an entire clump. They’ll need to be watered well, especially the ones that have top-heavy flowers on them, and then baby-sat a bit till they resettle, but the divisions typically bloom the next year.

My favorite day to do this: a rainy one, like today. The graphic below shows the simple steps in photos:

how to divide trillium

anatomy of a trillium (and how to grow them)

(From Tony Avent at Plant Delights)

Trillium foetidissimum from Plant Delights Nursery‘TRILLIUMS have an interesting anatomy,” Tony Avent writes in the Plant Delights catalog. “The three ‘leaves’ that give trillium plants their characteristic form are actually bracts. The true leaves are greatly reduced structures that surround the underground rhizome. Trillium seeds are also fascinating…they are attached to a nutritious structure called an elaiosome that insects love to eat. When trillium seeds are ripe, ants and wasps carry them to their nests where they consume the elaiosome and leave the seed to germinate…a horticultural win-win situation.”