Aristolochia – Pipevine

I can highly recommend Aristolochia macrophylla (synonyms: Aristolochia durior, Aristolochia sipho) to all garden lovers seeking a climber to grow in partial or full shade. It belongs to the family Aristolochiaceae.

Its imposing size has earned it the nickname of the “gentry bush” in some regions of Poland. Aristolochia macrophylla is a climbing plant attaching itself to supports using leaf petioles and clockwise-twining stems. It grows up to 10 m high, producing 1-2 m of new growth a year.

Young stems are deep green and turn grey-green with age. It has very characteristic large, heart-shaped leaves up to 30 cm long, the upper side deep green, the bottom blue-green. In autumn, just before falling, the leaves turn yellow. The flowers are very unusual: slightly fragrant, yellow-brown-green, they open up in May-June and resemble a pipe 2 – 4 cm long, on a long stipule and with a wide-open bowl, hence the English name “Dutchman’s pipe”.

The flowers act like a trap for insects. Once an insect has entered a tube, they keep it captivated for some time, and thus, without any sinister designs, they force it to carry out a thorough pollination.

The blooms are usually hidden under the leaves and so may be difficult to spot. The fruits have a form of a bag resembling a little cucumber, about 6 – 10 cm long and 3 cm across.
They ripen in September, turn brown and split into 6 pieces scattering numerous, small, flat, triangle-shaped seeds.

Aristolochia macrophylla rarely sets fruit in a cool climate, such as the Polish one, although some particularly prolific specimens can produce fruit and seeds every year.
Its large leaves overlap and form covers as thick as almost no other plant and thus provide deep shade for fences, pergolas or arbors. Dutchman’s pipe also looks decorative in winter with the tangle of its leafless green stems.

Requirements.
Dutchman’s Pipe is a long-lived shrub and can live even for a few dozen of years. It’s fully frost hardy and tolerates well urban conditions. Thrives best in half-shade, but will also grow in full shade. In a sunny position, especially a dry one, it is very vulnerable to spiders. It requires fertile, moist to moderately moist soils that are not too heavy, and prefers chalky or neutral soil to acid one. It doesn’t like positions exposed to strong wind.

Culture.
It’s a rampant grower that creates a large mass of greenery, and as such it needs a sturdy support. Planted next to an old tree, live or dead, it will wrap around its trunk and branches and create a charming crown. After planting into a final position it needs two years to settle and start growing vigorously. During that time you should prune it to encourage branching. In the following years pruning isn’t needed and should only be applied when the plant has spread out excessively. You can cut it back without fear, as it will grow back well even after hard pruning.
Due to its vigorous growth, it requires annual fertilizing and abundant irrigation, especially during hot summers.

Aplication.
Aristolochia macrophylla is ideal for creating screens, covering pergolas, arbours and high fences. It looks very attractive when climbing up pylons, columns and old trees. It can also be used as groundcover. Owing to a great mass of greenery it produces, it needs sturdy supports, e.g. lattices, ropes or chains. It’s suitable for public green spaces.

Aristolochia macrophylla is native to the eastern part of North America. It was brought to England in 1762 and arrived in Poland in 1808, at the Botanic Garden in Cracow.
The genus Aristolochia comprises over 300 species of perennials and bushes, mostly climbing in habit. The majority are native to tropical climate. Only a few of them, apart from Aristolochia macrophylla, are capable of growing without any screens in cooler climatic conditions:

• Aristolochia manshuriens – Chinese aristolochia. A rampant climber originating from Far East (China, Korea, Russia), similar to Aristolochia durior in appearance and requirements, and almost equally ornamental. Large leaves are slightly pubescent.
• Aristolochia tomentosa – Woolly Dutchman’s pipe (Aristolochia tomentosa) – native to northern America, is a vigorous climbing plant with small, densely hairy leaves. Considerably less decorative and less valuable than Aristolochia durior and Aristolochia manshuriens.

• Aristolochia clematitis – Birthwort (Aristolochia clematitis). A non-climbing, perennial plant native to southern Europe. Raised stems that reach the height of 1.5 m, heart-shaped leaves 10 – 15 cm long and yellow flowers in May-June. It produces numerous root stolons. Suitable for large parks or garden landscapings, to use in half-shade. However, it gets easily out of control and becomes a rampant weed.