Hibiscus syriacus ‘RED HEART’

Rose-of-Sharon deserves more attention for its abundant flowering in summer. These maintenance-free shrubs come from eastern Asia and are the inevitable ingredient of every summer garden which they highlight with a wide range of coloured flowers. There has been a number of cultivars available since its discovery. They have various bloom colours, shapes and sizes, as well as varigated leaves.
Red Heart bears snow white flowers with conspicuous burgundy red hearts, hence the name. There are often veins of the same colour running from the inside.
It has very decorative leaves that are unique. They are narrowly palmate, 3-lobed, mid to dark green and coarsely toothed. If they turn yellow in summer the plant manifests too much water at the roots. They are either over-watered or planted in too heavy, water-logged soil that might cause serious problems. Hibiscus is a typical example of a plant where the borderline between favourably moist soil (which they need) and wet soil can be tricky. Our advice is: water it well when you plant it, mulch it well and let it be well. Only when you see the leaves are drooping water it again.
I am quite surprised when I read comments about its pruning. Especially in older encyclopedias and on some West-European and American websites it is recommended to prune it every spring after frosts to encourage better flowering. Our hibiscus plants were only trimmed when they were young, and we did it before we planted them to achieve a compact shapes if the plants were delivered unsightly. Then nothing. They are located in different places throughout the garden with various soil types and quality, and they all grow relatively the same speed = medium slow (10-15 cm per year). Such short branches, however, are fully mature, woody and well branched which is a guarantee for profuse flowering the following year. If you prune your hibiscus hard, it may result in larger flowers but also in too long branches that will need to be trimmed again next year, and on and on. The only cut I suggest is when you need to reduce size of an old specimen.
Rose-of-Sharon is quite adaptable of soil type. As explained above it likes moist but well-drained soil, medium fertile. Older plants dislike peat. Selective fertilizers for better flowering are convenient. Place it in full sun. Fully hardy to min. -27°C (USDA zone 6, very likely 5).
Last update 23-06-2009.

The Rose of Sharon (Hibiscus syriacus) also known as an Althea shrub is a mid summer bloomer in white, pink, red, or purple with a red center. You can also find them ruffled in the same array of colors including what many call blue. You can grow the Rose of Sharon as a shrub or a tree and many garden catalogs sell them as a fast growing deciduous flowering hedge.

The Rose of Sharon grows in zones 5-9

I have seen a listing for up to zone 11. In my zone (7) it can be invasive and pop up where the seeds may fall or the wind takes them. Many sites will tell you that the height can reach up to 10′ tall and 6′ wide but I can confirm that I have a ruffled purple one that is 8 years old and is well over 12′ tall and 6′ wide. It has never had viable seeds yet and last summer transplanted a purple one to the same area of the yard to see if that will make a difference (sometimes plants need another for cross pollination). It grows in most soils and will tolerate the hot summer sun.

The Rose of Sharon can be a prolific reseeder

About 3 years ago I discovered under the Oak tree on the front corner of my property along the street quite a few seedlings. Since the seedlings were mixed in with the Wintercreeper Euonymous under the Oak tree, I just let them to see what they would do. Well, last summer 2 purple and 1 pale pink bloomed so I dug up the 2 purple ones and left the pale pink one under the Oak by the road. I transplanted one (purple) on the side of my house where it is hot and dry and I put the other one in my back yard. (I believe) the seeds came from my neighbor 4 houses down and across the street. She has a purple one but no one else on my street has a Rose of Sharon that I have found.

Flower is done for the day

My double ruffle blooms around the 1st week in July and shortly after the others start to bloom. I have one in part shade and it has not bloomed yet but has buds. This is a late bloomer and would not be a good specimen tree for any garden because the leaves emerge much later than most other deciduous shrubs and trees. The Rose of Sharon does make a great hedge and I would think about mixing it in with some sort of conifer, evergreen, or arborvitae for winter interest. The Rose of Sharon can be controlled by simply cutting off thee seed heads before the pods turn brown and burst open. If the seedlings emerge, you can simply pull them out of the ground. I threw down seeds late last summer and this spring they emerged. These are fast growing plants. The first year they will grow less than a foot but by the 3rd year my Rose of Sharon tree has reached over 6′ tall. Now I live in zone 7 so I have a longer growing season and a milder winter but I would venture to guess that a foot a year growth until it reaches maturity is not over stating how fast they grow.

The seed pod burst and already released the seeds

The Rose of Sharon can be pruned to control its size. I am not a pruner so I let (most of my) plants do what they will. If you do want to prune I would wait until the last flower blooms and fall arrives to prune to shape for next year. You can also prune in early spring and shape the plant (some gardener says for bigger blooms). The Rose of Sharon can be a bush, tree, or even an espalier (which is training the plant to grow along a fence or wall).

Bee magnet

I have never fertilized my ruffled Rose of Sharon and had any disease problems but that does not mean they cannot succumb to blight, leaf spot, or canker. This year, however, there seems to be an aphid problem which I need to address with a shower of Dawn dishwashing liquid in my fertilizer hose sprayer. It has been written that the Rose of Sharon is also one of the favorites of the Japanese Beetle. (so knock on wood that I do not find this out)

There are new cultivars you can find at garden centers and nurseries which are smaller and are not invasive (because the plant does not produce many seeds). The bees love them which is a plus in my book. The Rose of Sharon also tolerates my dry, red clay soil and life under Oak trees which is another reason I have them.

I have so many seedlings because I do not prune off the seed heads. It is easy to identify them and pictured below I have a close up of the leaves for you to use to identify them on your hunt. I would save the pictures and go for a walk in your neighborhood and see who has them. I would ask the gardener (or property owner) if they would mind if you took some seeds or dug up some of the seedlings. Many people will share and asking is so much better than just taking.

Leaf ID

I have transplanted these in the heat of summer with great success. Watering is the key to success and transplanting before, during, or after a rain is my secret. Happy gardening everyone and if you ever have a question, just ask.

Creating. Inspiring. Gardening without the rules!

Bloom bud and spent flower

2017 copyrighted material C Renee

single stem to train as a tree notice 2 trunks which will grow more into a bush multiple trunks on my Ruffled Rose of Sharon another small Rose of Sharon with double trunk

Here’s to Rose of Sharon

To Prune or Not to Prune?

Beyond a fresh layer of mulch in spring, routine care includes pruning (if desired) in late winter or very early spring. Some gardeners cut their shrubs back very hard – to 3 or 4 buds per shoot — to control overall size and encourage larger blooms. Others simply take the laissez faire route and let their shrubs grow into their natural shape. This latter approach encourages more, smaller blossoms. The plant blooms on the new wood of the current season — summer trimming means that you’ll lose out on flowers.

She’s a hardy plant with gorgeous blossoms that needs little care — what’s not to love?

Barbara Martin is National Gardening Association’s reporter for the Mid-Atlantic region. Maggie Oster also contributed to this article.

Photography by Barbara Martin/National Gardening Association

Luscious Bloom

Breeders have developed some lovely flower colors — white, pink, red, violet, and lavender-blue — available in single or double forms. Rose of Sharon sports her blossoms, which resemble those of other members of the mallow family, from mid- to late summer. I especially like the blue ones, such as ‘Blue Satin’ (although to my eye they are still more blue-violet than true blue, except in soft early morning light). Many of the double-flowered types seem almost more like oversized rose trees, with eye-stopping, multi-layered crepe paper flowers. The white-flowered cultivars are perfect for an all white summer “moon garden,” and the many pinks and purples work well among the pastels of English-style gardens.

Also, the U. S. National Arboretum has introduced new cultivars in recent years that are triploids. The flowers are large, but they don’t set seeds, so blooms are produced over a long period. ‘Diana’ is among the best of these introductions, with pure white flowers that remain open at night. The foliage is a waxy and dark green. ‘Aphrodite’ has rose-pink petals that are red at the base. ‘Helene’ has white flowers with deep red centers with streaks forming many-pointed stars. ‘Minerva’ has lavender-pink flowers with a red center.

I first noticed the hardy shrub called Rose of Sharon (Hibiscus syriacus) while traveling one midsummer across the southern plains. I saw it over and over again, blooming bravely in dooryard gardens despite the sizzling heat on the rough, wind-swept prairies. That’s when I discovered that this large, summer-flowering shrub reliably brings pleasure and beauty, whatever the weather dishes out. That, to me, is the sign of a quality plant.

This native of Asia and India was introduced to the U.S. in 1790. Hardy in USDA Zones 5 through 8, Rose of Sharon thrives in full sun and isn’t too fussy about soil, as long as it’s not sodden or very dry. The vase-shaped shrub grows 8 to 12 feet tall and to 6 to 10 feet across, but can be pruned to a smaller stature. Many books suggest using Rose of Sharon in a shrub border rather than as a specimen plant in the yard, but I’ve noticed that those grown alone develop a much better shape than those crammed in a shrub border.

If you plant Rose of Sharon in fall, don’t be dismayed in springtime if it looks dead while surrounding plants are busily sprouting away. The three-lobed leaves emerge quite late. I, for one, am willing to accept this quirk because of the shrub’s contribution to the summer garden. There is nothing to equal its stately presence amidst the daylilies, coneflowers, reblooming clematis, and sweet peas, with butterflies and hummingbirds all around it. Not bad for a low-maintenance, workhorse of a shrub!

While some gardeners find its persistent, woody seed pods an asset in the winter landscape, many gardeners shun Rose of Sharon – at least the old fashioned type – for the prolific, weedy offspring. This group will be won over by recent introductions, including triploid and tetraploid varieties, that set little if any seed.

As for pest problems, there are few. Japanese beetles love Rose of Sharon, so be prepared with your favorite means of beetle avoidance, be it traps, repellents, or grub control.

Rose of Sharon, Shrub Althea ‘Red Heart’

Height:

8-10 ft. (2.4-3 m)

Spacing:

4-6 ft. (1.2-1.8 m)

Hardiness:

USDA Zone 5a: to -28.8 °C (-20 °F)

USDA Zone 5b: to -26.1 °C (-15 °F)

USDA Zone 6a: to -23.3 °C (-10 °F)

USDA Zone 6b: to -20.5 °C (-5 °F)

USDA Zone 7a: to -17.7 °C (0 °F)

USDA Zone 7b: to -14.9 °C (5 °F)

USDA Zone 8a: to -12.2 °C (10 °F)

USDA Zone 8b: to -9.4 °C (15 °F)

Sun Exposure:

Sun to Partial Shade

Bloom Color:

Red

White/Near White

Bloom Time:

Mid Summer

Late Summer/Early Fall

Foliage:

Deciduous

This plant is resistant to deer

Other details:

Unknown – Tell us

Soil pH requirements:

6.6 to 7.5 (neutral)

Patent Information:

Non-patented

Propagation Methods:

From woody stem cuttings

From softwood cuttings

From semi-hardwood cuttings

From hardwood cuttings

Self-sows freely; deadhead if you do not want volunteer seedlings next season

Seed Collecting:

Allow pods to dry on plant; break open to collect seeds

Foliage Color:

Blue-Green

Bloom Characteristics:

This plant is attractive to bees, butterflies and/or birds

Water Requirements:

Average Water Needs; Water regularly; do not overwater

Requires consistently moist soil; do not let dry out between waterings

Where to Grow:

Unknown – Tell us

Regional

This plant has been said to grow in the following regions:

Tuscaloosa, Alabama

Carmichael, California

Crockett, California

Deland, Florida

Fort Walton Beach, Florida

Conyers, Georgia

Chicago, Illinois

Saint Cloud, Minnesota

Saucier, Mississippi

Jefferson City, Missouri

Blair, Nebraska

Kearney, Nebraska

Lincoln, Nebraska

Auburn, New Hampshire

Jersey City, New Jersey

Willingboro, New Jersey

Croton On Hudson, New York

Cleveland, Ohio

Dayton, Ohio

Dundee, Ohio

Glouster, Ohio

Painesville, Ohio

Westerville, Ohio

Hulbert, Oklahoma

Oakland, Oregon

Salem, Oregon

Clairton, Pennsylvania

Coatesville, Pennsylvania

Lebanon, Pennsylvania

Pittsburgh, Pennsylvania

Greenville, South Carolina

Greeneville, Tennessee

Jackson, Tennessee

Summertown, Tennessee

Talbott, Tennessee

Arlington, Texas

Longview, Texas

North Zulch, Texas

San Antonio, Texas

Santa Fe, Texas

South Jordan, Utah

Cathan, Washington

John Sam Lake, Washington

Langley, Washington

North Marysville, Washington

Priest Point, Washington

Shaker Church, Washington

Stimson Crossing, Washington

Weallup Lake, Washington

show all

Red Heart Rose Of Sharon flowers

Red Heart Rose Of Sharon flowers

(Photo courtesy of NetPS Plant Finder)

Red Heart Rose Of Sharon in bloom

Red Heart Rose Of Sharon in bloom

(Photo courtesy of NetPS Plant Finder)

Height: 10 feet

Spread: 8 feet

Sunlight:

Hardiness Zone: 5b

Other Names: Shrub Althea

Description:

A wonderfully distinctive variety of this old-fashioned favorite featuring ostentatious pure white flowers with the most prominent rich ruby-red blotch at the base of each petal surrounding a white stamen cone; commands attention in the garden

Ornamental Features

Red Heart Rose Of Sharon features bold white trumpet-shaped flowers with ruby-red centers along the branches from mid summer to early fall. It has green foliage throughout the season. The lobed leaves do not develop any appreciable fall color. The fruit is not ornamentally significant.

Landscape Attributes

Red Heart Rose Of Sharon is a multi-stemmed deciduous shrub with an upright spreading habit of growth. Its average texture blends into the landscape, but can be balanced by one or two finer or coarser trees or shrubs for an effective composition.

This is a high maintenance shrub that will require regular care and upkeep, and is best pruned in late winter once the threat of extreme cold has passed. It is a good choice for attracting butterflies and hummingbirds to your yard, but is not particularly attractive to deer who tend to leave it alone in favor of tastier treats. Gardeners should be aware of the following characteristic(s) that may warrant special consideration;

  • Insects
  • Disease

Red Heart Rose Of Sharon is recommended for the following landscape applications;

  • Accent
  • Mass Planting
  • Hedges/Screening
  • General Garden Use
  • Container Planting

Planting & Growing

Red Heart Rose Of Sharon will grow to be about 10 feet tall at maturity, with a spread of 8 feet. It tends to be a little leggy, with a typical clearance of 2 feet from the ground, and is suitable for planting under power lines. It grows at a medium rate, and under ideal conditions can be expected to live for 40 years or more.

This shrub does best in full sun to partial shade. It prefers to grow in average to moist conditions, and shouldn’t be allowed to dry out. It is not particular as to soil type or pH. It is highly tolerant of urban pollution and will even thrive in inner city environments. This is a selected variety of a species not originally from North America.

Red Heart Rose Of Sharon makes a fine choice for the outdoor landscape, but it is also well-suited for use in outdoor pots and containers. Its large size and upright habit of growth lend it for use as a solitary accent, or in a composition surrounded by smaller plants around the base and those that spill over the edges. Note that when grown in a container, it may not perform exactly as indicated on the tag – this is to be expected. Also note that when growing plants in outdoor containers and baskets, they may require more frequent waterings than they would in the yard or garden.

Rose of Sharon Shrubs

Rose of Sharon is a deciduous flowering shrub and is botanically known as Hibiscus syriacus. Rose of Sharon is also known as althea or hardy hibiscus. Rose of Sharon is a native of Asia. Rose of Sharon prefers full sun and well drained, moist soils.

Althea is a beautiful shrub that does not take much care and they will do well in average soils. Rose of Sharon blooms in late summer and into the fall. They bloom profusely making this shrub one of the most attractive of late summer flowering plants. Rose of Sharon is a heat lover and can easily tolerate summer heat. They also leaf out late in the spring so do not be alarmed if all the other plants are leafed out and the hibiscus is not.
Rose of Sharon is a multi-stemmed shrub, but they can be pruned to grow as a tree like plant with a single main trunk. Pruning should begin in the first or second year of growth to create a single trunked rose of sharon. Prune the Rose of Sharon in late winter. Light or no pruning will allow the Rose of Sharon shrubs to bloom profusely with smaller flowers. Heavy pruning will create larger but less flowers.

Nature Hills has several varieties of Rose of Sharon. Click the photos to learn more, or call our plant experts at (888) 864-7663.

Hibiscus syriacus, the common garden Hibiscus is also called Rose of Sharon. It is a flowering shrub native to much of Asia. It is vase-shaped, reaching 2-4 meters in height. Hibiscus syriacus is the national flower of South Korea. The flowers come in several colors, including white, pink, purple, blue, red or bicolors, with a different colored throat, depending upon cultivar. Continuous blooms often occur from July through September. The flowers can reach 2-4 inches in diameter. The flowers are hermaphrodite, they have both male and female organs. Plants are late coming into leaf, usually around the end of May or early June. The foliage is deciduous. The leaves are 2-4 inches long, they have three distinct lobes with sparsely dentate margins, and are medium to dark green. Fruits green to brown capsule 0.75″ long. The trunk is white-gray and relatively smooth, branching very near to the ground unless limbed up into tree form. Since plants bloom on new growth, shaping or pruning can be done at any time; prune in late Winter or early Spring in northern climates. Hardiness zones 5-9, (-26°C/-15°F, -5°C/25°F) in Winter. When planted in colder areas, they will need protection for the first few Winters. It prefers a well-drained humus rich fertile soil in a position in full sun. Plants grow best with their roots in cool moist soil and their tops in a hot sunny position. The tree is very adaptable to various soil pHs, soil compaction, drought, heavy pruning, and pollution. It will succeed in any soil of good or moderate quality.

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