Glaucidium palmatum

By Todd Boland

It seems the choicest garden plants hail from Japan or China and that does indeed seem to hold true! They have hosts of spectacular rhododendrons, magnolias, maples, etc. It’s hard to get a more exotic-looking plant than Dicentra spectabilis (bleeding heart)! For alpine and woodland enthusiasts, another choice Japanese plant is Glaucidium palmatum.

I’ve seen and coveted this plant for many years. A Google search will reveal sites that describe this plant as a rare Japanese woodlander, not easy to grow, one of the most highly prized plants in horticulture. Prices range from $20 US for the normal species to $60 US for the white form! Even the seeds sell for upwards of $4.79 US for just 10 seeds.

Glaucidium palmatum is native to northern Japan, primarily Hokkaido. There, it grows as a woodland plant in montane to sub-alpine forests. They emerge quite early in spring, growing to 40 cm in height. Each stem produces a pair of bright lime-green maple-like leaves. The 8 cm diameter flowers are solitary with 4 petal-like sepals and a dense fluff of yellow stamens in the centre. The overall effect is decidedly poppy-like, hence the common name horned poppy. They flower locally from late May through June. The flowers are often somewhat small when they first open but increase in size as they age. The standard colour is mauve to lilac-purple but a pure white form also exists.

Being a woodland plant, it thrives in moist, humus-rich soil. Both the RHS and AHS list it as hardy from zone 6-9, but I know gardeners in zone 4 who are successfully growing it. On the other hand, continental areas of zone 6-9 will have difficulty with this plant since they prefer rather cold soils. Ideally, the Pacific NW, Atlantic Canada and the immediate coastal areas of New England have the best success with this species.

Taxonomically, Glaucidium has had a confused past. It was originally placed in the Poppy Family, Papaveraceae, then into the Buttercup, Ranunculaceae. More recently, it was separated, along with the Peonies, into the Peony Family, Paeoniaceae. A few years ago, taxonomists decided that Glaucidum didn’t really fit comfortably in the Peony family, and now has been placed into its own family, Glaucidiaceae. I’m sure the plant could care less!

As for my personal experience with this plant, I was given a pot of three seedlings in 2000 by one of our local Newfoundland Rock Garden Society members. She said to plant them as one as they resented disturbance. I was so delighted to finally have one that I would do whatever she suggested! I planted them in deep, humus-rich soil in a part of my garden that only gets late afternoon sun (incidentally planted under Magnolia sieboldii and Chamaecyparis pisifera, both which also hail from Japan-China). The next spring, the three plants reappeared along with 4 additional seedlings! Obviously, there were some ungerminated seeds from the original sowing. In spring, 2002 I was rewarded with a single lavender bloom. It fulfilled my every expectation. In 2003 I had two lavender blooms and one white! I didn’t expect to luck into the rarer white form but by then the plants were so intertwined that I didn’t dare attempt to separate them. In 2005 I was rewarded with nine lavender blooms and three white. The plant is obviously happy in its site and I have been delighted with its performance. Since then I have collected and germinated my own seed; quite easy if you sow them fresh and leave them outside for the winter.

Glaucidium may be difficult to buy locally and if available, may be pricey. However, they are reasonably easy from seed if you have patience. If you can find a seed source, then I highly recommend you grow this fantastic woodlander quoted as being one of the most highly prized plants in horticulture!