24 Feb 2011

The Holy Trinity of Woodland Plants

I had to snicker when I read that Trillium as a genus is considered an American icon! I almost choked on my  apple pie come to think of it! Trilliums, while native to North America, hold a special place in the heart’s of Canadian gardeners, specifically those living in Ontario, as it is our provincial flower. Nice try Armitage!

Trilliums are also know as wakerobins, toadshades and trinity lilies, hence the title of this posting! As a genus, it has its widest distribution in North America. A few species are  found in southern Kamchatka, the area surrounding the Sea of Japan, including eastern Russia [Siberia], eastern China [Amur region], Korea, Japan and the Himalayas. Interestingly none are found in Europe or in Asia west of and south of the Himalayas. Mores the pity! Lucky for the plant collector, there is a burgeoning list of new and exciting species that are definitely prone to pique more than an idle curiosity! 

Botanists have subdivided the genus into two subgenera; the stalked trilliums [subgenus Trillium] and the sessile species. [subgenus Phyllantherum] Those that are stalked have flowers on a pedicel, with spreading petals, whereas the sessile species tend to be stalkless and sit on the topmost whorl of foliage. Their petals are typically erect. These charming sessile species only occur in Eastern North America and are coveted for yet another distinctive feature: their fabulously marbled foliage!

trillium kamtschaticum
[L: Trillium kamtschaticum]
North American Indians used their rhizomes as a uterine stimulant during childbirth, while other herbalistic uses include the treatment of eye conditions. The Linnaean name Trillium, dating back to 1745, was derived from the Latin ‘tri’ [three] an illusion to the petal and foliage configuration. Most are hardy to Zone 5, originating in moist, shady woodlands. Those from and within the southern ranges are said to withstand less moisture, actually preferring dry conditions while in their dormancy. It is these very dry arid conditions of southeastern North America that force them into an early dormancy. A deep, consistently moist woodland soil, amended with plenty of organic matter, will likely extend a bloom period for two or more weeks – every shady gardeners ideal! It should be noted that by most gardening standards, this genus is considered ephemeral – with an early, and relatively short flowering period. Most species are very deeply rooted, so it is essential to follow this method when attempting to cultivate them in a garden setting.  Do not site them in too shallow, or too dry an area. If they are given proper cultural conditions, they can be a long lived species that will happily form extensive colonies over time.  Some choose to grow theirs in raised beds with a deep soil mixed with sandy clay, peat, pine bark, pine straw and wood compost. Ideal pH for most mid eastern species ranges between 6-7. Never collect plants from the wild, and always inquire as to where garden retailers are sourcing their plant from. It is best to buy from those who grow them from seed, or if available and reliable, from nature advocacies who have rescued plants from endangered areas. Here are a few personal favourites that I am either growing, or have on order for the coming season:

[Trillium rivale: Pink Seedling Selections] was ordered from Thimble Farms. One of the daintiest and most diminutive, I was instantly smitten with the fact that they actually open a blushed pink, as opposed to most white species that only turn pink as they age! Flowers are small, usually 2-2.5cm across. This is one that demands cool. sandy peat soils and must never dry out! Hardy to Zone 6, but blooming happily in my Zone 5 garden!

Trillium kurabayashii is without a doubt one of the most commented upon, thanks in large to its magnificently mottled foliage! Often considered the western of T. cuneatum, with slightly larger, conspicuous purplish red flowers. It is also hardy to Zone 6, but because it is so early to appear in Spring, there is an increased threat of damage from late frosts. I tend to keep mine covered with pine boughs until the threat of frost has been extinguished!

trillium chloropetalum
Trillium chloropetalum remains on my must have list! It represents the sessile species like none other with its erect, broadly lance shaped petals and stunningly mottled foliage. The variety ‘giganteum’ is said to be more robust and larger than the type, with white to deep wine coloured flowers. The species is a wonderful addition to the woodland garden, but like T. kurabayashii, it’s early appearance in the garden is threatened by late frost. All documentation that I have uncovered rate this as no lower than Z6, with emphasis placed on the fact that even in some Zone 7 gardens, protection was essential for its survival. Note to self: More pine boughs for tender new Trillium species!

trillium tschonoskii
Trillium tshonoskii is one of those rare Eurasian species, native to Honshu, Hokkaido, Eastern Russia, North Korea and into the Himalaya. Very similar to T. kamtschaticum, with slightly smaller flowers that nod more! This one requires consistently moist, acidic soil. Hardy to Zone 4.

trillium undulatum
Trillium undulatum is one of the prettiest of all, hence its common name of ‘painted lady.’ An eastern North American native, this cool weather species is at home in the higher mountainous elevations and does well in gardens with cool summers so long as it has deep, very acidic, always moist soil to grow in. This is one that I look forward to every Spring.

trillium albidum
Trillium albidum, another of the sessile species, has unique purple stained throats which only adds to its stunning beauty! It is native of the northwestern United States from Washington to California.  Simply divine!

Trillium grandiflorum is perhaps the most common and sought after, as it is the best within the genus for gardens with its large flowers and foliage that persists until early Autumn. It enjoys slightly acidic soil, but is also quite amenable in circumneutral soils as well. Mine are ‘roseum,’ opening a blush pink.

trillium stamineum
Trillium stamineum is holding me captive as I type this! What a stunning plant. From what I can ascertain, it is native to Alabama, Mississippi and Tennessee. Its relatively small but unique flowers are made up of twisted petals that are held horizontally above two tone slightly mottled foliage. These flowers are said to carry a rather unpleasant fragrance. Is there anyone familiar with this stunning species who could enlighten me as to its requirements. Something tells me my Zone 5 garden will be too cold for it!
And last but not least…..

trillium gtandiflorum plenum
Trillium grandiflorum ‘Flore Pleno’ is considered by many to be the ultimate ‘Holy Grail’ woodland plant, with its fully double flowers that look more like a rose than a Trillium. I’m happy to give such an esteemed to my beloved Cypripedium reginae.  I’ve gazed down upon this wonder and have come away less than impressed. Having said this, beauty is in the eye of the beholder, and at nothing less than $75 a pop, I’ll stick to other rare and unusual beauties!


Aerie-el said...

Wonderful post! There isn't a Trillium I don't adore, and your comprehensive info makes me want MORE!

Alice Joyce said...


Michelle said...

I love trilliums! I have some photos on my blog of extremely dense trilliums.

Darla said...

I wonder which ones of these are the ones that grow around in our woods...I kind of believe it may be the 4th photo...I personally have none in my gardens.