Cercis canadensis, Eastern Redbud – 6 (4)

By Tom Atkinson

My first brush with the genus Cercis occurred in early April 1984 on a business trip to California that included a three-day nature tour of the Sierra Nevadas with my aunt and uncle. Scrambling around the foothills we discovered many delights including California buckeye (Aesculus californica) , Whipple’s yucca (Yucca whipplei) , manzanita (Arctostaphylus manzanita) and California poppy (Eschscholzia californica) , the state flower. Looking across the foothills, we could see patches of a delicate purple-red. As we drove closer, these distant smudges became western redbuds, Cercis californica, lovely in full flower. Knowing they would not be hardy back east, I vowed to get seed from our eastern redbud, Cercis canadensis, that fall. I returned to Toronto much-pleased with my discovery. And it was the only business trip, ever, from which I arrived home completely relaxed.

Cercis canadensis is a small deciduous shrub-like tree (up to eight metres or 26 feet high). Its mauve-pink, pea-shaped flowers bloom in spring on bare branches, before the lovely heart-shaped leaves (up to 13 centimetres or five inches wide) have a chance to emerge. The bark is smooth grey with reddish-streaks when the tree is young. In time, the flaky bark becomes a cinnamon colour, almost like Pacific madrone (Arbutus menziesii) .leaf colour is mid-yellow, quite bright and lively. Flat, reddish-brown pods hanging in clusters from the branches produce 10-12 shiny brown seeds per pod. These can be harvested any time after the seed pods turn dark brown, which means late fall through late winter.

My eastern redbud seeds were never scarified (the need to scarify is a myth perpetuated by otherwise reputable books), but rather shelled and outplanted in a garden bed. In spring the seed germinated readily. By the end of the growing season some seedlings were whips almost a metre high (three feet)! For maybe two seasons, there was major dieback. Thereafter, the shrubs/trees grew well and were tip-bud hardy. My fastest-growing redbud bloomed no more than six years from seed, a precocious phenomenon we propagators truly appreciate.

When you plant seed outside, do so in a prepared garden bed. I suggest planting seeds in a row so that when you see similar-looking plants in spring you will be less tempted to shriek “killer weeds!” and rip them from the ground. Cover redbud seed with no more than five millimetres (1/2 inch) of soil. If you fear predation by squirrels, line the row on either side with something heavy such as bricks. The sprouting seeds will push up between the bricks, but “bushy tail” will be thwarted in his zeal to till your garden bed.

Cercis canadensis will grow in almost any soil but it needs to be moist. The soil can be somewhat acidic to somewhat alkaline – ours is clay loam of about pH 6.8, which is good for market garden crops. Drought will cause leaf loss early on in redbuds, but a wet foot is not acceptable either. As a woodland tree, Cercis is accustomed to being in the understorey or on the verge between woodland and pasture. It will grow in full sun to considerable shade. The leaf litter decomposes into mulch readily.

Cercis canadensis occurs naturally in eastern North American woodlands and forest openings from Mexico north to Connecticut and Michigan and as far west as Nebraska. In Canada it is probably native only to Pelee Island although this is uncertain since it has been naturalized in Ontario. It is hardy to Zone 4.

The redbud is sometimes called the Judas tree because, as legend would have it, Judas Iscariot, who is alleged to have betrayed Jesus, hung himself in remorse from a redbud, (Cercis siliquastrum, native to Israel). The tree is said to have blushed with shame and has remained pink ever since. That said, there is a white version called C. siliquastrum alba which also grows in the Middle East. We have a white one too, named whitebud or C. canadensis alba. In colonial times, “Canada” was French territory, west of the Appalachian Mountains. Thus the appellation (pun intended) canadensis.

Although Cercis canadensis is not native as far north as Toronto (or has not been for perhaps 10,000 years), it does well in this region. If you clump several redbuds together or crowd them, their posture will be upright and less spreading. Open-grown specimens spread considerably. However you grow them (and strictly native or not) I would highly recommend that you find a place for this charmer in your yard.

Tom Atkinson is a native plant propagator living in Toronto. His primary interests are in rare woody and herbaceous plants, indigenous, of course, and those that are found in southern Ontario down through the eastern mountains of the United States.