Plant of the Month: Western White Trillium
I’ve been a big fan of trilliums since I was a kid in West Virginia. Out there you’ll find several species blooming in the woods. Here in northwest Washington we only have one native species, although there are others a bit further south or east in the Pacific Northwest. Our species, Trillium ovatum, is common, widespread, and showy.
Western white trillium, also known as wakerobin, is blooming in our woods right now. Recognize it by three showy white petals held just above three large triangular leaves. Did you pick up on the threes, which give the genus its name?
Trilliums are a woodland plant, growing in open shade mostly under hardwoods. They come up and bloom before the tree canopy is leafed out, taking advantage of early spring sunshine. They like a rich soil full of organic matter. If the conditions are right, trilliums will slowly multiply, going from a single stem to a dense clump over a period of years. In the photo above the trilliums are in Seattle’s Washington Park Arboretum, surrounded by fallen camellia petals.
We purchased trilliums, raised from seed, at a nursery and planted them in the shady part of our old garden in downtown Bellingham. They don’t take kindly to transplanting, so starting with seedlings from a reputable source is the way to get them going in your own garden. Once we planted them we gave them very little care and they thrived. We did notice that our slugs like their blossoms some years, which was disappointing.
Trillium blossoms open bright white and then fade to a soft pink. One of my pollinator experts tells me that the color change tells pollinators that the flower has already been pollinated and there’s no need to stop by. I’ve had people ask me if they’re a separate species, which is not the case.
Trilliums set seed fairly easily, with the seeds maturing in a hard, triangular-shaped pod where the flower was (the pod is the mature ovary). Seeds fall to the ground and germinate at the base of the plant. The first year, a plant will have just one leaf as it puts down roots. The second year it will have two leaves and its not until the third year that a plant gets its characteristic third leaf. It may be a year or two after that before it reaches blooming size.
Besides Trillium ovatum, Washington is also home to T. parviflorum, small-flowered trillium (older references may call it T. albidum or T. chloropetalum), which grows in southwest Washington from Pierce County south; and T. petiolatum, purple trillium, which can be found in Chelan County and the far eastern counties that border Idaho.
Occasionally you’ll find trilliums with four petals and four leaves. This one was growing above the ditch along Mt. Baker Highway headed to the Mt. Baker Ski Area. It’s the only time I’ve seen a “quadrillium.”