A small genus of only 7 species of plants though many more hybrids; that are native to temperate regions of Eurasia though often also planted in North America.
They are very tough but do have a preferance for full sun on fertile, well drained soil though some will also grow in the shade minus much of the blooms.
They are rarely bothered by insect pests, disease or deer.
Forsythias are generally grown for their early spring blooms however lately new cultivars with attractive summer foliage have also been developed.
The flowers are borne very early in spring, the foliage also emerges early, quickly following the blooms.
Propagation is from hardwood cuttings in autumn and winter or softwood cuttings taken in summer. Forsythia can often self layer forming dense inpenetrable thickets if branches scraping the ground are not clipped off. Pruning to shape can be done during spring immediately after blooming. Old stems that have lost their vigor can be removed. The flower buds are formed the previous year so fall pruning reduces flowering in the spring. The Forsythia can be used as a hedge, however using smaller types in limited spacing will save you tons of time and labor.
Old overgrown plants can be cut to the ground in late winter or immedately after blooming and will grow back vigorously.
Forsythia europaea ( European Forsythia )
An open erect shrub native to the Balkan region of Europe where it is endangered.
It rarely exceeds 6 feet in height though the record is 10 feet.
The ovate leaves, up to 3 x 1.5 inches, are deep green.
The pale yellow flowers are borne early spring.
Hardy zones 5 to 9.
Forsythia giraldiana
A somewhat open, arching shrub native to northwest China.
Some records include: largest on record - 17 x 13 ( rarely over 12 x 11 ) feet.
The ovate or elliptical leaves, up to 5 x 2.5 inches, are gray-green.
The pale yellow flowers are borne late winter. This is among the first of the Forsythia's to bloom.
Hardy zones 5 to 9, it is tolerant of floodplain conditions.
Forsythia mandshurica ( Mandshurian Forsythia )
A spreading, medium-sized, deciduous shrub, reaching up to 5 feet in height, that is native to Liaoning Province in northeastern China.
The papery, broadly-ovate or elliptical leaves, up to 5 x 2.8 inches in size, are mid-green.
The bright yellow flowers are borne during mid to late spring.
Hardy zones 3 to 6, it is among the hardiest of the Forsythias and even thrives in Finland.
'Vermont Sun'
A stiff, upright, medium size shrub, that is among the first Forsythia's to bloom. It blooms a week before Forsythia ovata. Some records include: 10 years - 9 x 11 feet; largest on record - 10 x 11 feet. It is almost unknown in the U.S.
The almost round leaves, are up to 5 x 3 inches. The flower buds are black.
Hardy zones 3 to 7; flower buds are hardy to at least as cold as -30 F. It is an excellent choice for North Dakota.
Forsythia ovata ( Korean Forsythia )
A fast growing, dense, compact shrub native to Korea.
Some records include: fastest recorded growth rate - 4 feet; 10 years - 5 x 5 feet; largest on record - 8 x 10 ( rarely over 6 x 8 ) feet.
The ovate leaves, up to 6 inches in length, are dull deep green.
The golden-yellow flowers, up to 0.7 inches across, are borne in very early in spring, 14 days before other varieties.
Hardy zones 3 to 9. It's very hardy flower buds are less prone to frost damage in zone 4 and 5 however may not bloom in zone 3
Floraliz'
Flower bud hardy to -30 F; it is even known to thrive in Calgary and Edmonton, Alberta however often not on the windswept prairie outside city limits.
Some records include: 5 years - 6 x 6 feet; largest on record - 10 x 10 feet ( est. ). The early spring flowers are bright yellow and the foliage is deep green.
'Nakkia'
Flower bud hardy to -40 F
'Robusta'
More vigorous, reaching a maximum height of 10 feet.
'Tetragold'
Very fast growing and dense with larger flowers up to 1.3 inches across. It is very hardy, even thriving in Alberta, Canada.
Forsythia suspensa ( Weeping Forsythia )
A widely arching dense large shrub that is native to central and eastern China. It is naturalized locally in eastern North America to as far north as Sauble Beach. Some records include: 10 years - 13 x 10 feet; largest on record - 12 x 20 + feet. It often spreads through layering ( the self rooting of branch tips that lay on the earth ) and sometimes invasively so. It can be trained as a weeping standard tree however it will need to be staked when young, pruned yearly in mid summer and in spring immediately after blooming and have all suckers and trunk sprouts removed. It can also be grown as a perennial, forming sprays up to 8 feet in length if cut to near ground immediately after blooming.
The ovate leaves, up to 5 x 2.5 inches, are sometimes divided into 3 leaflets. The foliage is medium green turning to dull yellow in fall.
The long lasting, golden-yellow nodding flowers, up to 1.3 inches across, are borne in early spring before the foliage.
The shoots are slender.
Hardy zones 6 to 9 ( possibly stem hardy to zone 4 but will not bloom there ) in full sun to partial shade.
* photos taken on April 6 2011 in Columbia, MD
* historical archive photos
'Atrocaulis'
Foliage is purplish at first before turning to green. The young shoots are also purple.
'Fortunei'
Stiffer, more upright and hardier ( north to zone 4 ). Extremely vigorous.
'Sieboldii'
Very spreading and lax in habit, often reaching no taller than 3 feet but having been recorded to reach up to 33 feet in width ( typically closer to 10 feet ).
Forsythia viridissima ( Green Stem Forsythia )
A vigorous, large, rounded, deciduous to semi-evergreen shrub native to southeastern China. It has naturalized locally in eastern North America to as far north as Wiarton. Some records include: largest on record - 15 x 15 feet.
The narrow leaves, up to 6 x 1.5 inches, are deep green, turning deep red in autumn.
The mid yellow ( with purple calyx's ) flowers are borne in axilliary clusters of 1 to 4 in early spring before the foliage emerges.
Hardy zones 5 to 9. It is tolerant of floodplain conditions.
* photo taken on Apr 2 2020 in Columbia, MD
'Bronxensis' ( Bronx Greenstem Foresthia )
A low, spreading form, reaching a maximum size of 3 x 5 feet.
The fine-textured leaves are lance-shaped and smaller, only up to 1.7 inches in length. The foliage turns to deep purple during autumn.
Pale yellow flowers are up to 1 inch across.
Hardy zones 5 to 9.
'Ilgwang'
A cultivar of var koreana. Colorful foliage, reaching a maximum size of 9 x 11 ( rarely more than 6 x 8 ) feet
* photo taken on May 6 2010 @ Brookside Gardens, Wheaton, MD
* photos taken on Mar 23 2011 @ Brookside Gardens, Wheaton, MD
* photo taken on Aug 20 2011 @ Brookside Gardens, Wheaton, MD
* photo taken on Mar 18 2017 @ Brookside Gardens, Wheaton, MD
* photos taken on Apr 23 2017 @ Brookside Gardens, Wheaton, MD
* photos taken on May 27 2017 @ Meadowlark Botanical Gardens, Vienna, VA
* photos taken on Aug 5 2017 @ Brookside Gardens, Wheaton, MD
* photo taken on Nov 10 2020 @ Brookside Gardens, Wheaton, MD
* photo taken on Aug 1 2022 @ Brookside Gardens, Wheaton, MD
* photos taken on May 6 2024 @ Brookside Gardens, Wheaton, MD
var koreana ( Korean Forsythia )
Originally very rare in North America, however the following cultivars are bound to reach stardom. This is one of the hardiest Forsythia, being native to Korea which is famous for severe winters.
'Kumson'
A fast growing, medium-size shrub. Some records include: fastest recorded growth rate - 4 feet; 5 years - 6 x 5 feet; 10 years - 8 x 8 feet; largest on record - 8 x 9 feet.
The attractive foliage that is deep green and heavily veined white, turn to purple during autumn. The foliage is often reddish at first in spring.
The yellow flowers are borne during early spring before the foliage emerges.
Hardy zones 4 to 9
* photo taken on October 15 in Howard County, MD
* photos taken @ U.S. Botanical Garden, Wash., DC on Aug 25 2014
* photos taken on May 3 2017 in Columbia, MD
* photo taken on May 12 2023 in Columbia, MD
* photo taken on Oct 21 2023 in Columbia, MD
* photos taken on Mar 18 2024 in Columbia, MD
'Klein'
A low, spreading form, reaching up to 2 x 5 feet in size, Though similar to Forsythia 'Gold Tide' in habit, this one has the added attraction of repeat blooming during the fall.
Hardy zones 5 to 9.
FORSYTHIA HYBRIDS ( Forsythia x intermedia )'
Of mixed parentage ( often Forsythia suspense x S. viridissima ) typically with toothed ovate leaves, up to 5 inches in length, that are deep green in summer turning to purple late in autumn. In reasonably mild climates, the leaves often persist into December. All have yellow flowers that are borne in early spring before the foliage emerges.
Most are hardy zones 5 to 8 ( hardier varieties are noted ). They even tolerate juglone contaminated soil near black walnut trees.
* photo of unknown internet source
* photos taken on Mar 20 2012 in Columbia, MD
* photo taken on Oct 5 2015 in Columbia, MD
* photo taken on Dec 3 2015 in Columbia, MD
* photos taken on May 14 2017 in Mountaintop, PA
Forsythia 'Arnold Dwarf'
A rapid growing, very dense, low growing shrub rarely reaching over 3 feet in height.
Some records include: 10 years - 3.3 x 10 feet; largest on record - 4 x 10+ feet.
If often spreads by layering ( self rooting of branch tips that lay on the earth ).
The foliage is bright green, later turning to deep green.
The early spring flowers are yellow-green but are not as profuse as some of the other hybrids.
Hardy zones 4 to 9 in sun or shade. An excellent groundcover, especially for commercial sites.
Forsythia 'Arnold Giant'
Some records include: largest on record - 3.5 x 7 feet
Hardy zones 4 to 9
Forstyhia 'Beatrix Farrand'
Very vigorous and large, reaching 6 x 6 feet or more.
The coarse foliage is deep green. The oblong leaves are up to 4 inches in length.
The abundant, large flowers, up to 2 inches or more across, are bright yellow.
It may not be flowerbud hardy north of zone 6 except during mild winters.
* photo taken on Apr 14 2015 in Columbia, MD
* photo taken on Apr 6 2020 in Columbia, MD
Forsythia 'Fiesta'
Festive green and yelloe center-variegated leaves. The elliptical leaves are up to 3.2 x 1.6 inches in size, and contrast with scarlet stems. It originated as a seedling within a grouping of Lynwood Gold Forsythias in Avon, Connecticut. Some records include: largest on record - 10 x 10 feet.
Hardy zones 4 to 9.
* photos taken on Mar 23 2011 @ Brookside Gardens, Wheaton, MD
* photos taken on Apr 23 2017 @ Brookside Gardens, Wheaton, MD
* photos taken on May 27 2017 @ Meadowlark Botanical Gardens, Vienna, VA
Forsythia 'Ford Freeway'
Vigorous and upright to arching in habit, reaching up to 12 x 10 feet in 10 years. This cultivar was originally discovered near the Ford Freeway in Detroit, Michigan.
The foliage is heavily splashed creamy-white. The leaves turn to an exotic combination of purple, deep pink and creamy-white during autumn.
It bears typical golden-yellow flowers during early spring.
Hardy zones 5 to 8.
Forsythia 'Golden Peep'
A compact, rounded, dense, dwarf Forsythia, only reaching up to 2.5 x 2.5 feet in 5 years, 3 x 4 feet in 12 years and 3.3 x 5 feet in 15 years which is likely as large as it will get. It originated as a mutation of ‘Spring Glory’ that was induced by gamma rays.
The very abundant, spring flowers are golden-yellow.
Hardy zones 5 to 8
* patent photos
Forsythia 'Gold Tide'
Easily kept under 2 feet in height with minimal pruning, this Forsythia is generally used as a low groundcover and makes a stunning display in early spring. Some records include: 4 years - 2.5 x 5 feet; largest on record - 4 x 10 feet.
The foliage is luxuriant bright green however the fall color isn't spectacular.
The very abundant flowers are bright golden-yellow.
Hardy zones 4 to 9.
* photos taken on Mar 23 2011 @ Brookside Gardens, Wheaton, MD
* photos taken on Apr 11 2013 in Columbia, MD
* photo taken on June 18 2013 in Columbia, MD
* photo taken on Sep 15 2013 in Howard Co., MD
* photos taken on May 21 2014 in Harford Co., MD
* photo taken on June 2015 in Harford Co., MD
* photos taken on Mar 29 2016 in Harford Co., MD
* photo taken on Mar 1 2017 in Howard Co., MD
* photos taken on Mar 9 2017 in Harford Co., MD
* photo taken on Aug 5 2017 @ Brookside Gardens, Wheaton, MD
* photo taken on Nov 9 2017 in Harford Co., MD
* photos taken on Mar 8 2018 @ Brookside Gardens, Wheaton, MD
* photos taken on June 5 2019 in Columbia, MD
* photo taken on Mar 25 2022 in Columbia, MD
* photos taken on Mar 14 2023 in Columbia, MD
Forsythia 'Golden Times'
Of Forsythia giraldiana parentage. A fast growing shrub with very attractive foliage that is variegated with a broad golden-yellow margin. The foliage is scorch resistant. Some records include: largest on record - 10 x 8 feet
Hardy zones 4 to 9 though the flower buds are hardy only zones 6 and warmer.
Forsythia 'Goldilocks'
A vigorous, compact, dense, upright-rounded shrub only reaching around 2.5 x 2.5 feet in 5 years, 4 x 4 feet in 11 years. It is an offspring of a Forsythia x intermedia ‘Spring Glory’ in France that was treated with gamma rays.
The abundant, bright yellow flowers are borne in early spring before the deep green foliage emerges.
The foliage turns to deep purple during autumn.
Hardy zones 5 to 8.
Forsythia 'Karl Sax'
Deep yellow flowers, up to 1.8 inches across, are borne abundantly during early spring then repeating sporadically during autumn. Foliage turns to purple in fall.
Some records include: largest on record - 10 x 8 feet
Hardy zones 4 to 9
* photo taken on Apr 8 2015 in Towson, MD
Forsythia 'Little Renee'
A miniature form, reaching up to 2 x 4 feet in 5 years, eventually to 2.5 x 6 feet. It is great for a low hedge or foundation planting.
The small, fine-textured foliage turns to deep red during autumn.
Hardy zones 4 to 8, it is flower bud hardy to -30 F.
Forsythia 'Lynwood Gold'
Prolific large deep yellow flowers with wide petals. Originating in North Ireland in the mid 1930s, this has since become one of the most popular Forsythias worldwide.
Some records include: 5 years - 10 x 12 feet; largest on record - 10 x 14+ feet
Hardy zones 4 to 9
* photos taken on April 2 2010 in Howard County, MD
* photos taken on Mar 16 2012 in Columbia, MD
* photo taken on Apr 11 2013 in Columbia, MD
* photo taken on Apr 11 2015 in Columbia, MD
* photo taken on July 17 2016 in Bayfield, Ontario
* photo taken on May 15 2018 in Columbia, MD
* photo taken on July 13 2018 in Bayfield, ON
Forsythia 'Magical Gold'
Moderate growing, compact and rounded in habit, reaching up to 5 x 5 feet.
The foliage is luxuriant mid-green.
It bears larger than average, intense golden-yellow flowers during early spring.
Hardy zones 5 to 8
* photo taken on May 8 2020 in Olney, MD
* photos taken on Mar 29 2024 in Laurel, MD
* photo taken on Apr 24 2024 in Elkridge, MD
Forsythia 'Meadowlark'
This hybrid between Forsythia europaea & F. ovata forms a fast groowing, rounded, large shrub.
Some records include: largest on record - 17 x 15 feet
Flowers are more bud hardy than any other Forsythia, hardy to -35 F, even blooming in zone 3 in North Dakota.
The leathery leaves are deep green, turning to purple during autumn.
Hardy zones 3 to 9.
* USDA-NRCS PLANTS Database / Herman, D.E.. North Dakota tree handbook
Forsythia 'New Hampshire'
A fast growing, dense, arching, mounded to rounded shrub, reaching a maximum size of 8 x 8 ( rarely over 6 ) feet.
The soft-textured mid-green foliage turns to deep red during autumn.
The very abundant, golden-yellow flowers are borne during early spring.
Hardy zones 3 to 9, with the flowerbuds being hardy to -35 F.
* photo taken on Apr 14 2015 in Columbia, MD
* photo taken on Apr 6 2020 in Columbia, MD
Forsythia 'Northern Gold'
Golden-yellow flowers, up to 1 inch across, borne in early spring.
The foliage is glossy bright green.
It forms a vigorous, upright, large shrub. Some records include: 5 years - 8 x 5 feet; 6 years - 8 x 7.5 feet; largest on record - 15 feet
Hardy zones 3 to 9, flower buds are hardy to -30 F though flowers buried under snow may be more hardy. The stems are hardier and this very tough plant even thrives in Alberta, Canada's tough climates.
Forsythia 'Northern Sun'
A strong growing, large shrub, averaging around 10 x 10 feet at maturity.
Some records include: largest on record - 17 feet.
The abundant, clear yellow flowers, up to an inch across, are borne early spring.
The leaves, up to 5 inches in length, are glossy mid-green.
Hardy zones 4 to 9. The flower buds and wood are tolerate -33 F with no damage.
Forsythia 'Princeton Gold'
A large, dense, broad upright shrub, reaching a maximum size of 10 x 10 feet.
The foliage is deep green, turning to purple during autumn. The oblong leaves average 3.2 x 1.2 inches in size.
The abundant, large, showy flowers, up to 2 inches wide, are golden-yellow. They usually appear over a period lasting around 2 weeks during early spring just before the foliage emerges.
Hardy zones 4 to 9.
Forsythia 'Show Off'
Compact, dense and upright-rounded, reaching up to 2.8 x 2.5 feet in 3 years with an eventual maximum size of 9 x 6 ( rarely over 6.5 ) feet. Some records include: fastest growth rate - 6 feet.
The attractive foliage is deep green. The elliptical leaves are up to 3.5 x 1.6 inches in size.
It very abundantly bears large, bright yellow flowers, up to 1.5 inches wide, during a period lasting up to 3 weeks during early spring.
Hardy zones 4 to 8.
* photos taken on July 6 2020 in Columbia, MD
* photo taken on Aug 9 2020 in Columbia, MD
* photos taken on Sep 5 2020 in Columbia, MD
* photos taken on Oct 6 2020 in Columbia, MD
* photo taken on Nov 18 2020 in Columbia, MD
* photos taken on Apr 6 2021 in Columbia, MD
* photos taken on June 16 2021 in Columbia, MD
* photos taken on Mar 12 2022 in Columbia, MD
* photos taken on Mar 26 2022 in Columbia, MD
* photos taken on Mar 22 2023 in Columbia, MD
* photos taken on Apr 5 2023 in Columbia, MD
* photo taken on June 2 2023 in Columbia, MD
* photos taken on Sep 2 2023 in Columbia, MD
* photos taken on Mar 31 2024 in Columbia, MD
* photos taken on May 22 2024 in Columbia, MD
* photo taken on Nov 21 2024 in Columbia, MD
Forsythia 'Spectabilis'
A vigorous, large, upright to arching shrub.
Some records include: largest on record - 15 feet.
The sharply toothed, oval leaves are deep green.
Abundant, very large, golden-yellow flowers, up to 2 inches across, borne during early spring.
Hardy zones 4 to 9
* photos taken on March 16 2012 in Columbia, MD
* photos taken on Mar 20 2020 in Columbia, MD
* photos taken on Oct 12 2023 in Columbia, MD
* photos taken on Oct 29 2023 in Columbia, MD
* photos taken on Nov 10 2023 in Columbia, MD
* photo taken on Sep 14 2023 in Columbia, MD
* photos taken on Mar 21 2024 in Columbia, MD
Forsythia 'Spring Glory'
A fast growing, medium-sized to large, arching, rounded, upright shrub. Some records include: largest on record - 10 x 14 feet.
The abundant, showy flowers are very bright yellow.
Hardy zones 4 to 9
* photos taken on Mar 17 2012 in Columbia, MD
Forsythia 'Sugar Baby'
Moderate growing, very compact and upright, rounded in habit, reaching up to 1.7 x 1.7 feet in 3 years, eventually to 2.5 x 3 feet. it is the dwarf form of Forsythia 'Show Off'.
The ovate leaves are up to 3 x 1.2 inches in size.
The intense bright golden-yellow flowers, up to 1.2 inches wide appear during a period lasting up to 6 weeks during early to mid spring.
Hardy zones 5 to 9 ( 4b on protected sites ), it appears to have excellent resistance to Phytophthora root rot.
* patent photo
Forstyhia 'Susan Gruninger'
Originating from Forsythia 'Lynwood Gold'; it is very similar except for having very attractive non-burning foliage that is green variegated with a bold creamy-white 0.25 inch wide creamy-white margin. Very vigorous, it can reach up to 10 x 12 feet in 10 years. It looks stunning with a background of deep green conifers.
Forsythia 'Weekend'
Upright and rounded in habit, reaching a maximum size of 8 x 7 ( rarely over 6 ) feet.
The foliage is deep green, turning to bronze-purple during autumn.
The abundant, large flowers are bright yellow.
Hardy zone 4 to 7.
ADDITIONAL CULTIVARS
https://www.freepatentsonline.com/PP24361.html
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Excellent overview! Thanks a lot!
ReplyDeleteI was on your blog too. Excellent landscape photography and among my favorite blogs ever!
ReplyDeleteShrubs to add that special touch to any garden or landscape. This is a beautiful shrub that brings a lot of color to your garden. They brighten dull spot lawn or landscape, its bright yellow color. Shrubs also add beauty and color to your flower and shrub plantings, this is a good color to wear during the spring and summer. It produces brilliant yellow flowers for your enjoyment during the hot summer days.
ReplyDeleteKarl Sax Forsythia