Ornamental Plants Annual Reports and Research Reviews 2000

Special Circular 177-01

Crabapples at Secrest Arboretum - Aesthetics and More: A 2000 Update

Erik A. Draper
James A. Chatfield
Kenneth D. Cochran

Introduction

Crabapples are highly prized as a way to add shade, foliage, colorful flowers and fruit to the landscape. Rather than choosing a tree just for bloom color, selection should be based on total aesthetic qualities. Total aesthetics includes the overall impact of diseases, insects, fruit, flowers, foliage, tree form, and growth rate of each crabapple selection.

Twenty-eight crabapple taxa growing at the Secrest Arboretum of The Ohio State University's Ohio Agricultural Research and Development Center (OARDC), were evaluated monthly from August 1993 to August 2000, with an additional 14 crabapple taxa evaluated from August 1997 to August 2000 only. The results of these evaluations are presented in this report, which is intended for use by nurseries, garden centers, landscape architects, landscapers, and homeowners.

This information can assist in providing an accurate depiction of each tree's response to the specific growing conditions in Ohio.

Materials and Methods

The crabapple research plot is located at Secrest Arboretum on OARDC's campus in Wooster, Ohio, and consists of a completely randomized design with three single plant replicates of each taxa. Twenty-eight crabapple selections were planted in 1984 and were rated from August 1993 to August 2000.

An additional 14 selections, indicated by an asterisk, were planted in 1994 and rated from August 1997 to August 2000 only. Fruit color and size, bloom color, tree form, incidence of scab, and overall aesthetic average are reported in Table 1. Fruit color and size, bloom color, and tree form were from observations made during 1995-97 and cross referenced with observations made by Father John Fiala.

Apple scab susceptibility ratings and observations were conducted yearly, during the months of June through August, 1994-2000, and those findings were compiled for this report. The aesthetic average was derived by rating all crabapples individually each month for overall aesthetic impact and the ratings for each taxon were compiled and averaged.

Table 2 provides the aesthetic average again, as well as the time of effective fruit display, and an expanded description of each crabapple taxon. These profiles offer the positive and negative aspects of aesthetics, and disease observations, according to the evaluations of the authors.

The time of effective fruit display was compiled from biweekly observations conducted from October 1995 through May 1998. Disease observations and ratings were compiled from findings noted and presented by the authors in other articles written for previous publications of this ornamental plants research circular.

Results and Discussion

The 2000 growing season should have been called "an ordeal of diseases!" Due to prolonged and plentiful periods of wet weather, the trees were constantly challenged by ideal conditions for disease development. In fact, two trees, 'Red Jewel' and 'Prairifire,' which until this year had been consistently scab free, developed scattered scab lesions on a few leaves.

Apple scab was so prolific this year that highly susceptible trees exhibited previously unobserved symptoms. These symptoms were a sudden collapse and death of all foliage on a spur. Entire branches of the tree would appear to collapse and die, but stem tissue was not actually dead.

Due to the heavy scab pressure, as soon as new leaves began to emerge, they were immediately overwhelmed by disease and these leaves died. This constantly blighted appearance caused many to believe that these branches really had died. Many trees that were highly susceptible to apple scab appeared almost leafless and an eyesore for most of this disease-happy growing season.

It was also a challenging year for fireblight. However, due to the heavy fruit load last year, many trees were mimimally affected because of the relative lack of flowers this season. Unfortunately, one crabapple cultivar, 'Golden Raindrops,' that was showing great promise as a truly outstanding crabapple for use in Ohio, was significantly affected by fireblight. This variety will continue to be monitored closely to evaluate its performance under Ohio's conditions.

Table 2. Crabapple Descriptions.
Crabapple	Aesthetic Rating Avg.1	Time of Effective Fruit Display2
* 'Adirondack'	2.5	late Aug. to mid-Dec.
Orange-red fruits, white flowers, narrow upright form. Positives: Tight columnar form; great autumn fruit/foliage combination; fruit ripens to a deep orange-red; fruit appears singular rather than clustered; consistent flowers are red-tinged. Negatives: Somewhat slow to establish and leafhoppers appear to relish the foliage. Diseases: No scab.
Malus baccata 'Jackii'	2.8	late July to mid-Dec.
Maroon-red fruits, white flowers, large broad round form. Positives: Reliable flowers; large, glossy green leaves (by far the best foliage of any crabapple in the plot); fall contrast of yellow and rust-colored leaves against attractive maroon-red fruit is outstanding; frosty temperatures cause bark to take on an orange cast. Negatives: Relative sparseness of fruit clusters and mediocre overall winter appearance. Diseases: No scab.
'Beverly'	3.6	late July to late Sept.
Bright pinkish-red fruits, white flowers, large broad spreading form. Positives: Consistent flowers; impressive fruit display from late summer through early fall; profuse pink buds opening to snowy white flowers in spring. Negatives: Muddied, rotted fruits turn black beginning mid-fall through winter; fruits partially eaten by birds, creating an unsightly mess on the tree; sprawling growth habit is awkward. Diseases: No scab; however, moderate fireblight noted in 1994.
'Bob White'	2.8	mid-Oct. to late Jan.
Gold-yellow fruits, white flowers, rounded form. Positives: Persistent, small, firm fruits maturing mid-winter into striking orange-gold color, an excellent color for winter landscape; exceptional floral display of delicate white blossoms opening from pinkish-red buds; overall one of the better yellow-fruiting selections of the plot. Negatives: Fruit/floral display alternates yearly from profuse to sparse; lacks summer appeal. Diseases: No scab.
* 'Camelot'	3.0	mid-June to late Oct.
Rose-pink fruits, white flowers, low open spreading form. Positives: Oblong unique-colored fruit; petite, lovely fuschia-tinged flower; diminutive size is great for space-limited areas; foliage dark green with burgundy overtones. Negatives: Very slow growing; dull leaf appearance. Diseases: Trace of scab.
* 'Canary'	3.0	mid-Aug. to early Nov.
Yellow fruits, white flowers, open spreading form. Positives: Bright yellow tiny fruits hang in clusters along branches to accentuate form; nice autumnal fruit/foliage effect. Negatives: Early defoliation from scab; fruit deteriorates rapidly to cider brown and falls off quickly. Diseases: Minor scab.
* 'Candymint'	2.0	early July to late Nov.
Purple-red fruits, pink flowers, low spreading form. Positives: Graceful low spreading form; reliable fruit/flower displays; burgundy-tinged leaves; new stems are a deep burgundy; new foliage is striking, shiny wine-red. Negatives: Very slow growing; fruit display is never overwhelming; dull summer leaf appearance. Diseases: Trace of scab in years with high disease pressure.
'David'	3.0	mid-Sept. to mid-Nov.
Scarlet fruits, white flowers, rounded form. Positives: Abundant snowy-white flower display; impressive cherry-like fruits; nice tree form. Negatives: Yearly floral/fruit displays alternate from profuse to sparse; large mummies hang from late fall to mid-winter; mediocre summer appeal. Diseases: Trace of scab.
'Dolgo'	3.9	early Aug. to mid-Sept.
Red-purple plum-like fruits, snowy-white flowers, large rounded form. Positives: Consistent, early annual bloomer; almost neon red-purple fruits are edible; fruit impressive for a brief period during mid-summer. Negatives: Major fruit mess due to fruit drop; overripe fruit smell is intoxicating; lacks ornamental effect for much of the year. Diseases: No scab.
'Donald Wyman'	2.5	mid-Sept. to late March
Bright red fruits, white flowers, large broad round form. Positives: Excellent floral display; persistent glossy fruits remain effective, turning mud-red after a freeze; attractive exfoliating bark on mature trees. Negatives: Tenacious fruit mummies hang into early summer; heavy fruit scab repeatedly reduces overall appeal. Diseases: Minor scab on leaves but major scab on fruit.
M. floribunda	3.0	mid-Oct. to early Nov.
Yellow fruit, white flowers, broad spreading form. Positives: Airy floral display of pink-red buds opening to white flowers; great commingling of yellow and cider-brown fruit colors for autumnal effect; feathery effect of pedicels in winter. Negatives: Yellow flecking of foliage in summer; very short fruit impact; relatively ordinary appearance for much of the year. Diseases: Trace of scab.
* 'Glenn Mills/Winter Gem'	2.4	late Aug. to mid-April
Bright red fruits, white flowers, large rounded form. Positives: Dependable annual bloom; petite, firm, shiny fruit is sensational; incredibly long-lasting fruit effects; fast growing, large, consistent tree form. Negatives: Mediocre summer appeal. Diseases: Minor scab mainly on leaves.
* Golden Raindrops'	2.4	mid-Oct. to early Dec.
Yellow fruits, white flowers, open spreading form. Positives: Petite, lemon-yellow fruits; interesting cutleaf, glossy deep-green foliage; reliable fruit/flower display; great autumnal leaf color; contrasting yellow-orange bark. Negatives: Bland green fruit throughout the summer; tree form unruly without pruning. Diseases: No scab; fireblight in 2000 was a problem.
'Harvest Gold'	3.1	late Oct. to mid-Dec.
Yellow fruits, white flowers, upright open form. Positives: Attractive butter yellow fruits mature to golden yellow; nice contrast of red pedicels against fruit clusters. Negatives: Long period of bland green fruit well into mid-fall; leaves hang on for a long time hiding the fruit; awkward, gangly form; extensive fruit scab. Diseases: Major scab on leaves and fruit; some fireblight problems.
'Indian Magic'	2.6	mid-June to early April
Orange-red fruits, pink flowers, broad round form. Positives: Outstanding fruit display; unbelievable autumnal orange-red fruits with golden yellow underside; emerging foliage a pleasing burgundy; fall foliage an apricot-orange color; unfailing pink floral show. Negatives: Tenacious fruit mummies; defoliation in mid to late summer from scab although fruit scab is minimal. Diseases: Major scab.
'Indian Summer'	3.0	early June to mid-Feb.
Red fruits, rose-red flowers, broad round form. Positives: Consistent annual, large blooms; prolific mid-summer to fall display of large red fruits; contrasting fruits complement yellow-orange fall foliage. Negatives: Persistent fruit mummies; early defoliation from scab. Diseases: Major scab.
* 'Lancelot'	2.8	early Oct. to early Dec.
Yellow fruits, white flowers, dense round form. Positives: Diminutive size is great for space-limited areas; consistent tree form; fruit is a pleasing mix of cider and yellow. Negatives: Extremely tight, dense tree form; fruit/flower mostly hidden on the interior of the tree. Diseases: Trace of scab.
Liset'	3.2	early July to mid-Dec.
Maroon-red fruits, rose-red flowers, open round form. Positives: Consistent fruit display; nice fall contrast of fruits with peach-colored foliage; new foliage is deep burgundy and matures to a bronze green. Negatives: Awkward splayed growth habit; minimal fruit-foliage contrast; fruit mummies hang on until late fall. Diseases: Trace of scab. Note: Unusual but apparently normal splitting of bark along branches and trunk is characteristic.
* 'Louisa'	1.7	late July to mid-Nov.
Cream-gold fruits, pink flowers, true weeper form. Positives: Arching, graceful branches are upswept at ends; tree form is greatest asset; fruit darkens to a gold-orange with a tan blush. Negatives: Fruit is scattered and sparse. Diseases: No scab.
'Mary Potter'	2.2	mid-Aug to late Nov.
Red fruits, white flowers, weeping-spreading form. Positives: Petite, abundant masses of reddish fruit; profuse pink buds open to an exquisite blossom display; elegant spreading growth habit; salmon-colored underbark revealed as older bark peels away. Negatives: Fruit mummies a distraction during winter months. Diseases: Trace of scab.
'Molten Lava'	2.0	early Aug. to mid-Dec.
Red-orange fruits, white flowers, spreading-weeping form. Positives: Consistent, profuse flower/fruit shows; fiery red fruits and yellowing fall foliage on cascading branch structure create a "molten lava" effect; excellent winter ratings due to layered horizontal branching; feathery effect created by red pedicels after fruit drops. Negatives: Somewhat cluttered as tree matures; lacks summer appeal. Diseases: Minor scab.
* 'Narrangansett'	2.9	early Sept. to mid-Dec.
Cherry-red fruits, white flowers, upright spreading form. Positives: Nice flower display; abundant, firm fruit. Negatives: Cluttered, dense branching structure; tendency toward alternating sparse and abundant yearly flower displays ; awkward tree form. Diseases: Major scab on leaves and fruit.
'Ormiston Roy'	2.5	late Aug. to late March
Orange-yellow fruits, white flowers, broad round form. Positives: Very attractive glossy orange-yellow fruits with cream underside and red blush; orangish deep-furrowed bark colors as temperatures drop; nice, consistent floral show. Negatives: Tenacious mummified fruit may remain up to one year. Diseases: Trace of scab.
* 'Pink Satin'	3.3	mid-Aug. to mid-Oct.
Dark red fruits, pink flowers, upright spreading form. Positives: Very nice true pink bloom; fruit a pleasing red with yellow underside. Negatives: Persistent blackened mummies can be overwhelming; heavy fruit scab; cluttered branch structure. Diseases: Major scab on leaves and fruit.
* 'Prairie Maid'	2.6	early June to mid-Nov.
Rosy-red fruits, deep pink flowers, round spreading form. Positives: Reliable wonderful flower display; abundant clusters of small fruit; emerging foliage is burgundy red. Negatives: Lacking in winter appeal; waxy coating dulls fruit finish until coating weathers off. Diseases: No scab.
'Prairifire'	2.4	late June to early Dec.
Purple-red fruits, coral-red flowers, round form. Positives: Yearly spectacular bloom contrasts emerging red-tinged green foliage; firm purplish fruits slowly age to cherry red; fall colors of orangish spur leaves contrasts fruits and other foliage; unique lenticel-speckled bark. Negatives: Mediocre winter and early summer appearance. Diseases: Trace of scab in 2000; completely scab-free in other years.
'Professor Sprenger'	3.5	late Sept. to mid-Nov.
Orange-red fruits, white flowers, upright spreading form. Positives: Dependable, large, attractive white flowers; large orange-red fruits; young tree form with fruit is stunning. Negatives: Muddied mummies persist until late winter; awkward growth habit and tree form with maturity; dull appearance of large yellow-green fruit during the summer. Diseases: No scab; however, extensive yearly defoliation from frog-eye leaf spot.
* 'Purple Prince'	2.6	late June to late Dec.
Blue-purple fruits, rose-red flowers, broad round form. Positives: Large, dark unusual colored fruit; very nice yearly fruit/flower display; fast growing tree; leaves deep purple green. Negatives: Lacking fruit/foliage contrast; mediocre winter appearance. Diseases: No scab.
'Red Jade'	2.3	late Aug. to mid-Nov.
Red fruits, white flowers, weeper-spreader form. Positives: Graceful spreading growth habit adds winter interest; attractive oblong fruits; yearly prolific red flower buds open to large white blossoms. Negatives: Unsightly fruit rot; scab on fruit can dull appearance. Diseases: Minor scab on leaves and fruit.
'Red Jewel'	2.9	early Sept. to mid-April
Cherry-red fruits, white flowers, narrow upright form. Positives: Phenomenal firm fruits are appealing well into spring; very attractive blooms. Negatives: Mediocre late winter to early spring appearance; very slow growing; tenacious mummies; tree form a bit awkward. Diseases: Trace of scab just in 2000; some fireblight problems.
'Red Splendor'	3.1	late May to early Nov.
Red fruits, rose-pink flowers, upright spreading form. Positives: Exceptional profuse, red fruits age to orange-salmon color by mid fall; red-tinged new emerging foliage; reliable fruit display and lovely pink flowers. Negatives: Severe Japanese beetle feeding; early defoliation due to scab; poor winter ratings due to rotted, half-eaten mummies. Diseases: Major scab on leaves and fruit.
M. sargentii	2.7	mid-Aug. to early Nov.
Red fruits, white flowers, low wide spreading form. Positives: Greatest asset is attractive low-spreading growth habit; petite snowy white blossoms; effective firm fruits in late summer to early fall. Negatives: Fruits deteriorate rapidly; shriveled raisin mummies persist into winter. Diseases: No scab.
'Sentinel'	2.8	late Sept. to early March
Red fruits, white flowers, vase-shaped form. Positives: Columnar growth habit; sensational floral display of profuse red-pink buds opens to pink-tinged white flowers; pleasing yellow fall foliage contrasts fruits; attractive firm fruits persist into early spring. Negatives: Tenacious fruit mummies hang into summer; mediocre summer appearance. Diseases: Trace of scab only in years of high disease pressure.
* 'Silver Drift'	2.6	mid-Sept. to mid-April
Cherry-red fruits, white flowers, broad round form. Positives: Very persistent showy fruit; nice contrast of last year's fruit with emergence of new leaves in spring; fast growing tree; consistent tree form; retains leaves even though affected by scab. Negatives: Tenacious mummies; fruit obscured by foliage. Diseases: Minor scab.
'Silver Moon'	2.8	early Sept. to mid-Dec.
Burgundy fruits, white flowers, oval upright form. Positives: Glossy unique colored fruits; peculiar dense upright candelabra growth habit; good late, snowy white floral show. Negatives: Alternating yearly bloom from profuse to sparse; poor winter ratings due to somewhat cluttered growth. Diseases: No scab; occasionally fireblight can be a problem.
* 'Sinai Fire'	2.4	mid-Aug. to late Oct.
Red-orange fruits, white flowers, unique spreader form. Positives: Uncommon open growth habit with horizontal branches; good specimen plant; yearly floral show with large blooms. Negatives: Fruit scattered and sparse; slow growing; unique form is not for every landscape. Diseases: No scab.
'Snowdrift'	2.9	mid-Aug. to mid-Nov.
Salmon-red fruits, white flowers, broad round form. Positives: Reliable excellent flower show; distinctly colored attractive fruits; feathery and colorful effect of pedicels in winter. Negatives: Fruits shrivel by late fall; chlorotic summer foliage. Diseases: Major scab.
'Strawberry Parfait'	2.5	mid-Aug. to mid-April
Red-cream fruits, pink flowers, unique spreader form. Positives: Fruits age to deep red; newly emerged foliage red-tinged; unusual erratic upright-spreading growth habit; good fall color; fruits remain firm through late winter. Negatives: Tenacious fruit mummies; unusual shape is not for every landscape. Diseases: Trace of scab.
'Sugar Tyme'	2.6	early Sept. to mid-April
Brilliant red fruits, white flowers, rounded form. Positives: Stunning sugar-white floral display; showy, persistent firm fruits through late winter; good overall form; dense foliage. Negatives: General mediocrity if flowers/fruits are not abundant; fruit drops all at once before bloom. Diseases: Trace of scab.
'White Angel'	3.1	mid-Oct. to early Feb.
Red fruits, white flowers, broad upright form. Positives: Reliable, attractive flowers; showy medium-sized abundant fruits; red coloration of previous season's growth. Negatives: Awkward splayed growth until tree matures; tenacious mummies distract during mid- to early spring. Diseases: No scab.
'White Cascade'	2.7	mid-Sept. to mid-Nov.
Yellow fruits, white flowers, true weeper form. Positives: Exquisite flower display of cascading flower-covered branches; appealing overall tree form. Negatives: Perpetually dingy foliage throughout summer from scab; fruit scab completely destroys any potential fruit effect; early and extreme defoliation. Diseases: Major scab on leaves and fruit.
M. zumi 'Calocarpa'	2.8	late Aug. to mid-Dec.
Bright red fruits, white flowers, round spreader form. Positives: Excellent yearly flower show; clusters of abundant tiny, shiny red fruits; feathery pedicel effect in winter. Negatives: Fruits shrivel and deteriorate rapidly in early winter; lacks winter appeal. Diseases: Trace of scab.
* Denotes crabapple selections for which there are only four years (1997-2000) of observations. 1 Aesthetic ratings are from 1993-2000 unless an asterisk is present by the crabapple name, which denotes there is only data from four years (1997-2000) of observations. Ratings include flower, foliage, form, and fruit characteristics, and effects of disease and pest problems. The rating system is as follows: = Exceptionally ornamental crabapple. Based on outstanding flower, foliage, fruit, or form at time of rating. = Highly ornamental crabapple. Good flower, foliage, fruit, or form at time of rating. = Adequate as a landscape crabapple. Not highly ornamental at time of rating. = Substandard as an ornamental crabapple at time of rating. = Ornamentally unacceptable as a landscape crabapple at time of rating. Not recommended for use in the landscape. 2 Time of Effective Fruit Display derived from biweekly observations conducted October 1995 through May 1998. Effective fruit impact is defined as the period from when the tree's fruit first contributes to tree aesthetics until the fruit is no longer ornamental.

Selected References

Fiala, Father John L. 1994. Flowering Crabapples - The Genus Malus. Timber Press, Portland, Oregon.

Draper, E. A., J. A. Chatfield, and K. D. Cochran. 1996. The Magic of Malus. American Nurseryman. August 15, 1996. 184(4). pp. 46-55.

den Boer, John H. 1995. Blossom Times. Malus - The International Ornamental Crabapple Society Bulletin. 9(1). pp. 10-16.