In Praise of REDBUD
Eastern redbud (Cercis canadensis) is a fast-growing, undemanding, relatively short-lived (30-50 years) deciduous tree native to eastern North America. I refer to this common weedy species as the woody harbinger of spring. Its clustered scentless flowers emerge before the leaves -- early April in central Indiana. The flowers persist for several weeks. I occasionally encounter a web post listing redbud as fragrant. I wish! The fragrance claim is one or all of the following: (1) fabrication, (2) BS from an unreliable source trying to persuade (trick) you in to buying, or (3) some blogger passing on false info (i.e., not based on actual experience). Always consider the source! Again, I wish it was fragrant. By the way, Dirr and other reputable sources make no mention of fragrance. If you know otherwise, from personal experience, please let me know the specifics. I will expect no responses.
The peduncled zygomorphic flowers of redbud are produced on the trunk and at the base of all branches, except the current year's new shoots. This behavior is referred to as cauliflory (literally, stem flowering). The typically red budded and pink to lavender flowers are borne in axillary fascicles. The flowers are edible -- a potential colorful garnish that I prefer raw -- both tasty and nutritious. Judas tree is another common name for this lovely small arborescent, based on the attribution of Judas having hanged himself from a different species in the same genus. As an aside, it would be difficult to hang yourself from Cercis canadensis. I say small tree but one should understand that all woody plants exhibit indeterminate growth. Redbuds typically reach 20-25+ feet tall with a canopy that frequently is slightly wider. Redbud trees are commonly multi-trunked due to a tendency of producing basal sprouts, and the tree's branches are mostly low arching. Moreover, except perhaps as it relates to some of the weeping and dwarf forms, the common use of shrub-like to describe redbuds is inaccurate, except when they are younger. Redbuds are small trees albeit sometimes with a disproportionately large trunk. I have seen specimens with a trunk two feet in diameter! The young redbud branches are somewhat zigzag. The zigzagging is more pronounced in some forms, especially the weepers. The bark of younger redbud stems is dark grey and reticulate (see pic). Bark on the main trunk is somewhat scaly to peeling with a cinnamon under layer. I have grown to appreciate and enjoy the appearance of older specimens which often feature a knobby trunk and are asymmetrically misfitted, i.e., a large more aged trunk, frequently with cavities, and different sized and much younger branches, the result of dieback and subsequent new growth -- reminds me of the classic weathered faces Sergio Leone featured in his spaghetti westerns.
One thing people should understand about redbud is that all specimens eventually benefit from pruning, both the deadwood and to shape. Additionally, as a member of the bean family (Fabaceae), redbud is a nitrogen fixer (i.e., produces its own fertilizer) and can be weedy (by seed). Fortunately, redbud is not as prone to lateral asexual growth like some members of the family (e.g., black locust). Moreover, redbuds often produce abundant fruit. Unlike some people, I enjoy the fruit display which commonly remains on the plant overwinter. The flattened and tapered +4-inch pods are green when young. Later on they turn dark brown and can occasionally appear with a hint of dark burgundy when the lighting is just right, then contrasting wonderfully with the heart-shaped leaves which turn a golden yellow in fall. In windy conditions the clustered persistent paper thin dried fruit with enclosed hard seeds can produce an audible rattling. One of the often unappreciated instruments in Nature's multitudinous orchestra. By the way, the young emerging vegetation of most redbuds will be pink to wine; the pigmentation is noticeably absent in the pure white flowered forms. The pigmentation serves to prevent damage to the delicate new growth -- think sunscreen.
Redbud exhibits excellent morphological plasticity thus there are numerous cultivars, both upright and weeping, normal sized and dwarf. If buying, do not settle for the regular form! There are over three dozen named cultivars of eastern redbud. The ones I have grown or observed are listed below, with special attributes noted (i.e., the variance from the norm). Note that the actual/expected leaf color is dependent on exposure. Almost all are asexually propagated. Moreover, and not surprisingly given the number of cultivars, there is considerable feature overlap. For various reasons, including redundancy, there are several dozen illegitimate names, which I will mostly not cover here.
'Ace of Hearts' - a dwarf, vase-shaped "patio plant" with limited fruit production; flowers of the plants I have seen seem to tend towards lavender; introduced by the renowned (Don) Shadow Nursery (TN) which has released some great plants (like 'Slender Silhouette' sweetgum) but this form of eastern redbud does not appeal to me
'Appalachian Red' - originally called 'Appalachia', the flowers are darker and brighter, but not quite red; this mutant/cultivar was discovered along a roadside in Maryland
Carolina Sweetheart® 'NCCC1' - purported to be a dwarf but yet to be determined (has not been available long enough for there to be old specimens -- an all to common presumption/problem); this beauty has spectacular tricolored mottled new growth vegetation, a streak leaf hybrid ('Silver Cloud' x 'Forest Pansy')
'Flame' aka Plena - 1902 (O'Fallon, IL) origin (William Holden's hometown); a double-flowered pink form which sets flowers later, almost at the same time as the leaves emerge; the plant appears more upright and likely has non-functional flowers since it rarely produces fruit; suppressed fertility is common in plena (double-flowered) forms of other species
Flame Thrower® - a recent introduction with breathtakingly impressive new foliage which emerges in a strong burgundy-red; turning first yellow, then green as the leaves age
'Floating Clouds' and 'Silver Cloud' - recent releases with white-variegated foliage; the variegation in 'Silver Cloud' variegation is more marginal; 'Floating Clouds' (discovered in SC) is clearly superior, a visually stunning plant that produces flowers later, even after leaves start to emerge, and it seems to produce less fruit
'Forest Pansy' - full-sized purple leaf form; discrepancy re origin, either found growing wild in Missouri OR TN nursery (1947); Pansy may be good for breeding but I do not recommend, I have seen too many skanky / afflicted older specimens
Golden Falls® - a weeping dwarf with leaves more a lemon to lime than golden
'Hearts of Gold' - origin NC; the heart part (leaf shape) is accurate but the foliage is more a lemon-lime green until fall; I have trouble distinguishing this named cultivar from Rise 'N Shine®, essentially a less spectacular 'The Rising Sun' (i.e., no apricot)
'Lavender Twist' and 'Vanilla Twist' - excellent weeping/contorted forms with lavender or white flowers, released by my friend and super plantsman Tim Brotzman (Brotzman's Nursery, Madison OH); 'Covey' was the original (1991) name for what is often now called 'Lavender Twist'; the dwarf, weeping, somewhat contorted specimen was found at a private residence in NY state. 'Vanilla Twist' is 'Royal' x 'Covey'.
'Merlot' - a dwarf upright ('Texas White' x 'Forest Pansy'), purple leaves smaller and more lustrous leaves due to having Texas redbud genes, which also suggests it will be more drought tolerant; Texas redbud (C. canadensis var. texensis) is smaller, more upright, with more abundant darker flowers (more wine-red) and its leaves are thicker, smaller, glossier, darker green, with a wavy-margin, and are not pointed (reniform or kidney-shaped); the former name was C. reniformis. 'Oklahoma', a commonly available cultivar, is hardy in much of Indiana
'Ruby Falls' - a purple-leaved weeper ('Lavender Twist' x 'Forest Pansy') similar in size and form to 'Covey' but with superior lateral branching
The Rising Sun™ 'JN2' - the new growth is multihued, starting out with small leaves which are a show-stopping apricot and transitioning to larger leaves which are more yellow; green as the year progresses; one of my favorites; this spectacular mutant is a godsend 2006 discovery from Jackson Nursery, TN
'Royal White' - white (partially yellow) flowers. 'Alba', an invalid but sometimes applied name for this form, originated in a Carthage, Missouri nursery just after 1900; 'Royal White' was discovered as a seedling in Bluffs (western IL) in the 1940s; originally called 'Royal' and selected by Joe McDaniel (U of IL). While on my way to a plant conference in late April (2018) I witnessed hundreds of wild white redbuds growing along a raised road (Rte 62 & 69) between Mt. Vernon IN and the Wabash River to the west. Which brings me to experience the late great Wesley Whiteside (Charleston IL) shared with me when I was his student in the 1970s. Like magnolias, redbuds do not like to be transplanted. Many transplanted wild dug specimens of redbud die. If attempting to wild transplant, it is imperative to choose smaller specimens, do not try to bare root, and best done when the specimen is dormant. Also best to choose isolated specimens rather than what might be part of a connected clonal colony. Anthesis (flowering period) in the variegated forms also seems to occur later
'White Water' PPAF 'NC2007-8' - a recently released weeping form (from Broken Arrow Nursery, CT) with variegated leaves; the new leaves are a mottled pink and white transitioning to white and green; I would offer the variegated forms of redbud a site with some protection from afternoon sun
Zig Zag® 'Seirb' - a Spring Hill Nurseries release, the name zigzag says it all; the kind of unusual I like; I have not seen an older specimen but suspect they may be a tad dwarfed
Other cultivars / selections I have read about or heard described, but not observed, include: 'Alley Cat' (reported to be a superior white variegated form) from KY, Burgundy Hearts®, 'Cascading Hearts' ('Covey' like from TN), 'Crosswicks Red', ''Dwarf White' (IL origin), 'Greswan' ('Forest Pansy' like from OK), 'High Country Gold', 'JN16' ('Ruby Falls' x 'JN2'), Joy's Pride® ('Morton'), 'Little Woody', 'Mardi Gras' ('Amethyst Mist'), 'Melon Beauty', Northern Herald® ('Pink Trim'), 'Northland Strain' ('Minnesota Hardy'), 'Pauline Lily' (WV origin), 'Pinkbud' (Kansas City origin), 'Pink Heartbreaker' (vigorous weeper from PA), 'Pink Pom Poms' (an intriguing fruitless, double-flowered form -- 'Flame' by another name or a 'Flame' hybrid ?), 'Rubye Atkinson', 'Solar Eclipse' ('JN3', sport of 'JN2'), 'Summer Towers® ('JN7'), 'Tennessee Pink', 'Tom Thumb' (SE US), and 'Wither's Charm' (1930 WV). For more specifics I would refer you to A Checklist of Cercis (Redbud) Cultivars by Kidwell-Slak & Pooler (2018) HortScience 53(2): 148-152.
The remarkable Michael Dirr also praises redbud; "If there was a National Tree of the Year, redbud would be my first candidate". And, also from Dirr, "no equal, no competitor, can be found among small flowering landscape trees". Go online and look at images of the plants and you will see that the tantalizing descriptions are not hyperbole. Moreover, I have imagined (fantacized) a white flowered form with purple/red leaves, but not sure it is genetically possible since leaf and flower pigmentation are linked. By the way, the new growth of redbud has a characteristic drooping, both the end of the branch and the heart-shaped leaves. Further, the leaf arrangement of some forms have a curious stacked (imbricate) appearance.
Like many plants, redbuds are especially appealing when young, often less so as they age. Although, as noted above, I have come to enjoy the "survived" almost tortured look frequently exhibited by older specimens. They have character. Nature in all her beauty. Part of the reason for the gnarly look and the need for pruning is that redbuds are susceptible to several diseases and insect issues. Dead branches and hollow trunks are common. The trick to pruning redbud or any other woody plant is to do so skillfully, paying particular attention to make sure it doesn't look like it just had a hair cut.
Finally, there may be tough times ahead for eastern redbud and flowering dogwood (Cornus florida) in landscaping. My buddy Ryan Volz, who manages the woody species at Rosie's in Indianapolis, recently told me that growers south and east of Indiana are concerned about the future availability of these species due to a problem that afflicts the vascular tissue making it difficult to propagate the plants. Makes me wonder whether the mutants and hybrids might be more or less tolerant. We are going to find out.