Forestiera acuminata (Swamp Privet)


Michael's Opinion

An underutilized specimen that should be used more often where the situation is right. For example, it could be used more often in public parks around ponds or in lowland areas where moisture is adequate. It is absolutely stunning in spring when the flowers emerge. The ornamental bark, leaves, fruit and autumn colour provide interest all year round. Because of this, I feel that it would draw a lot of eyes in a public setting. Definitely one of my favourites in the Olive family.

Botanical Information

FamilyOleaceae
GenusForestiera
Speciesacuminata
CategoryWoody
TypeTree (deciduous)
OriginSoutheastern United States. South Carolina to Florida, as far west as Texas and Kansas.
Ethnobotanical Uses
Disclaimer
This plant is mostly used for its ornamental appeal; however, I discovered that the roots and bark can be used to make a tea that is drunk as a health beverage. The wood is strong and close-grained, so perhaps it could be used for its lumber as well. Fruit can also be eaten as a food source.

Details

USDA Hardiness Zone5 - 8
USDA Hardiness Ref.
Canadian Hardiness Zone4a - 8a
Canada Hardiness Ref.
RHS Hardiness ZoneH4 - H7
RHS Hardiness Ref.
Temperature (°C)(-29) - (-7)
Temperature (°F)(-20) - 20
Height3 - 9 m
Spread9 m
GrowthSlow
Flowering PeriodMarch, April

Description and Growing Information

General DescriptionA wild tree not often used in commercial locations. Grows in a shrubby form but can be trained to grow as a small tree. Extremely hardy. Significant ornamental value if pruned correctly. Fruit attracts birds and other wildlife.
ID CharacteristicEasy to spot in the spring by its distinct flowers, which emerge before the leaves. The bark and branches are very smooth and covered with pronounced lenticels. Leaves are deep green, glossy and have acuminated apices, with a pronounced, light brown central vein. When in fruit you will notice the grape-like structure and colour of the drupes.
ShapeOften shrubby in its native habitat, but it can be grown as a small tree. Very broad. Grow in an area with plenty of space for it to reach out as it grows. In maturity, if not pruned, this tree is as wide as it is tall.
LandscapeGenerally, not used in urban environments but is suitable for parks and lowland locations. It is used extensively as an erosion control tool and for naturalization purposes. When grown in public locations it can be used as screening because of its shrubby nature. In the wild it is a wildlife habitat and food resource for birds and fish.
PropagationPropagation by seed can be successful without stratification, but a stratification period of about 4 weeks increases germination success rate. However, fresh seeds have a much lower germination rate, suggesting that the plant may have a dormancy period similar to that of peonies. As for propagation by cutting, only cuttings from new, juvenile growth can be rooted, it seems cuttings from more mature growth can only be rooted with a synthetic auxin treatment. Both male and female plants have the same rate of germination.
CultivationThis tree is tolerant of most conditions. However, it experiences stress in high heat and is prone to drought stress as well. It would prefer to be planted in a lightly shaded area with soil that stays moist. Standing water is also acceptable as this plant is incredibly resistant to rot. As for soil, it can be planted in light to heavy soils, with pH levels from mildly acidic to neutral alkaline. Feel free to plant it in a completely shaded area, the growth will be slowed, but the tree will not experience stress. This tree is tolerant of salt and pollution, but I would not recommend planting it in urban areas unless you are meeting its high moisture requirements.
PestsNone that are serious. Deforestation and environmental change. Loss of our wetlands and the migration of fish and bird species that spread the plant’s seed. Some insects will feed on the leaves, but it is not known which insects.
Notable SpecimensChicago Botanic Garden, Chicago, Illinois, United States of America.
HabitatTypically found in swamps in southeastern United States, hence the common name; may also be found in low wet areas around ponds or lakes, wet wooded areas, or areas where flooding is common. Almost always in undergrowth.
Bark/Stem DescriptionNew growth is typically red or reddish-brown, as it ages branches will become grey or light brown. The trunk is covered in smooth brown or grey bark with pronounced lenticels. Bark is smooth to the touch.
Flower/Leaf Bud DescriptionSmall and insignificant, orange to red colouring, slight scaling and an acorn-like shape. They are distributed opposite along the branches with short internodal distances.
Leaf DescriptionLeaves are simple, ovate-oblong to ovate-lanceolate, acuminated apices, slightly serrated margins and can grow to 7.6 cm long, 1.5 cm wide. Their colour is deep green, but in early development they appear lime. They are glossy and have a pronounced central vein. They grow opposite along the branches of the plant with short internodal distances.
Flower DescriptionFlowers in late March to April on old growth before the first leaves emerge. The species are dioecious and the flowers are much more stunning on male plants. Yellow-Green in colour, they develop in bundles and are sessile. The flowers are incomplete; males are covered in stamens, giving the flowers an almost insect-like appearance, females only contain a pistil. Both flowers are cradled by sepals, but they do not have petals.
Fruit DescriptionAfter fertilization the female flowers develop into purple oblong drupes about 1.3 cm long by 0.8 cm wide. They generally ripen in May to June. This fruit is edible but doesn’t taste very good to humans. It is eaten by fish and ducks which, in turn, assists its seed dispersal. The fruit is fleshy and contains a single sizable pit that is light brown.
Colour DescriptionBranches are grey to light brown, but in early growth they are red or reddish-brown. Bark is brown or grey with pronounced lenticels. Leaves are lime in development and fade to a deep green as they age. In the autumn they are a beautiful golden yellow. Flowers are yellow-green, and the fruit is purple.
Texture DescriptionFinely textured plant. Texture remains the same all season.

Photographs