Rose of Sharon (aka Althea)
Hibiscus syriacus
Native to China and India, Rose of Sharon was introduced to the gardens of Europe in the 16th century. The specific epithet “syriacus”, refers to it having been collected from gardens in Syria. It is propagated by seed and cuttings, and many new cultivars have shown up in recent years. Many of these cultivars produce little to no seed.
Rose of Sharon is a deciduous, multi-trunk woody shrub to small tree that is cold hardy to Zone 5b (-15°F). It tolerates heat, poor soils and is drought tolerant once established. Although Rose of Sharon will thrive in a wide range of soils, it will not tolerate poorly drained soils. They will grow in a wide range of soil pH, from acid to alkaline (5.0-8.0).
This beautiful small tree blooms best in full sun but will tolerate light shade. Best blooming occurs if it receives 6 hours of sun a day.
What more could we ask for? How about relatively pest free? Aphids are occasionally found on the new growth or flower buds but can usually be controlled by a spray of water. It is susceptible to Cotton Root Rot, but really, what isn’t?
Flower colors are white, pink, dark pink, magenta, and blue, with some flowers having dark red centers. Single, semi-double and double flowers are available. Flowers are usually produced late spring through fall.
New introductions have different mature heights, so always choose the variety with the height that is desired. The “old fashioned” varieties grow to 8’-12’ x 6’-10’, while new hybrids may only reach 6’-8’ x 4’-6’. Some of these hybrids are also sterile or semi-sterile, so seed production is mostly absent.
Many of us remember this plant from our childhoods, when our grandmothers would have one planted in their yard. I would say the only drawback to this tree is the fact that it is a favorite “munchie” for the deer!
Here are some varieties that are found on the market today:
Blue Angel 6’-8’ x 4’-6’
single blue flower with
red eye
Aphrodite 8’-12’ x 6’-10’
ruffled clear pink with red eye
Minerva 8’-12’ x 6’-10’
lavender pink with dark red eye
Blueberry Smoothie 8’ x 4’
upright growth, double bluish-purple
Peppermint Smoothie 8’ x 4’
upright growth, double red
and pink blooms
Raspberry Smoothie 8’ x 4’
upright growth, double
raspberry pink blooms
‘Ardens’ 8’-12’ x 6’-10’
double lilac-purple blooms
‘Lady Stanley’ 8’-12’ x 6’-8’
very light pink double pink
with red eye
‘Amplissimus’ 8’-10’ x 6’-8’
double reddish-purple
‘Jeanne D’Arc’ 8’-10’; x 5’-6’
double pure white
with red eye
‘White Pillar’ 10’-15’ x 2’-3’
upright narrow growth habit with semi-double white flowers