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Kentucky wisteria

Kentucky wisteria growing on a trellis.

Kentucky wisteria is native to parts of North America.  This species produces hanging clusters of purple flowers.  It is a good alternate to the Japanese and Chinese wisterias that have become invasive in some areas. Also known as Wistaria frutescens var. macrostachya.

This plant has some cultivated varieties. Go to list of cultivars.

Botanical name:

Wisteria macrostachya

All Common Names:

Kentucky wisteria, Kentucky wistaria

Family (English):

Pea

Family (Botanic):

Fabaceae (formerly Leguminosae)

Tree or Plant Type:

  • Vine

Native Locale:

  • Illinois,
  • North America

Landscape Uses:

  • Massing,
  • Screen,
  • Specimen

Size Range:

  • Large plant (more than 24 inches)

Light Exposure:

  • Full sun (6 hrs direct light daily),
  • Partial sun/shade (4-6 hrs light daily)

Hardiness Zones:

  • Zone 5 (Chicago),
  • Zone 6,
  • Zone 7,
  • Zone 8,
  • Zone 9

Soil Preference:

  • Acid soil,
  • Moist, well-drained soil,
  • Wet soil

Tolerances:

  • Wet sites,
  • Clay soil,
  • Road salt

Season of Interest:

  • Early summer,
  • Mid summer

Flower Color & Fragrance:

  • Fragrant,
  • Purple,
  • White

Shape or Form:

  • Vining

Growth Rate:

  • Moderate,
  • Fast

More Information:

Size and Method of Climbing

Kentucky wisteria can grow 20 to 30 feet long.  It is a twining vine.  Twining vines climb by twisting their stems or leaf stalks around a support.  This type of vine grows well on trellises, arbors, wires or chain-link fences.

Plant Care

Full sun is preferable, but this vine will also tolerate partial shade.  A moist, well-drained, slightly acidic soil is best.  Avoid compaction.
Wisteria often do not produce flowers for the first 5 to 10 years.  To encourage flowering use nitrogen fertilizer sparingly and use a fertilizer that provides phosphorus (follow label directions).
Proper pruning will also encourage flowering.    After flowering, prune excess growth back to 6 inches.  These pruned stems will continue to grow.  In winter cut them again so that each stem has two to three buds left.  Proper pruning not only encourages flowering, but it also helps to manage size and shape of the vine.
Wisteria vines are heavy and require sturdy supports.

Disease, pests, and problems

None serious.

Disease, pest, and problem resistance

Tolerant of black walnut toxicity.

Native geographic location and habitat

Native to North America, mostly in southern states.  Native to a few counties in Illinois.

Leaf description

The opposite leaves are pinnately compound, with 9 to 11 leaflets.

Flower description

Purple, pea-type flowers in dangling clusters.  The clusters are 8 to 12 inches long and fragrant.  Flowers are produced in early summer.

Fruit description

Fruit are similar in appearance to pea pods.  Seeds are poisonous to eat (as are other parts of the plant).

Cultivars and their differences

Aunt Dee Kentucky wisteria (Wisteria macrostachya 'Aunt Dee'):  Flowers are light purple with a light fragrance.  This plant is considered slightly more hardy than the species and may perform well in zone 4.

Blue Moon Kentucky wisteria (Wisteria macrostachya 'Blue Moon'):  Blue-purple flowers.  This plant is considered slightly more hardy than the species and may perform well in zone 4.

Clara Mack Kentucky wisteria (Wisteria macrostachya 'Clara Mack'):  White flowers.

Location of Wisteria macrostachya (Kentucky wisteria) at the Arboretum