Dutchman’s pipe
Dutchman’s pipe is a strong growing and twining climber from the south east of the USA which can achieve a good 20ft in height if given a plant, trellis or wires to grow up and through. At Ventnor Botanic Garden A. macrophylla and other species of Aristolochia thrive outside as fairly hardy perennials growing on walls and through other evergreen shrubs. It grows perfectly well in sun or full shade and will survive the winters outside best in dry rather than damp or waterlogged soils while it is dormant. Pergolas or pillars are also ideal places to grow it.
This is a spectacular plant too for the greenhouse if you have enough space to let it romp. It has broad heart shaped leaves 4-12in long which are lighter coloured on their undersides. In summer it produces pairs or single flowers at the stem joints on long stalks. The tubular flowers are yellow-green outside with a flared brownish-purple mouth. The ‘tubes’ are bent in half and hence the common name “Dutchman’s pipe”.
Clearly this is a frost tender plant so propagation is important. Seed can be sown in the greenhouse as soon as ripe. The roots of A. macrophylla can be divided in the spring or root cuttings can be set in winter. Softwood cuttings should be taken in the summer and root quickly.
A. macrophylla needs a large pot in the greenhouse if you have no open bed to plant it in. Rich potting compost encourages fast growth and a monthly liquid fertiliser feed is advisable. Water sparingly in winter when it is dormant.