Mandevilla laxa

The Mandevilla laxa (or suaveolens), the Chilean Jasmine, is a beautiful deciduous South American rambler that should be seen more often in our gardens spared by heavy frosts. In its native mountains, temperatures a few degrees below zero are not uncommon in winter. It charms with its accommodating nature and endless fragrant white summer flowering at the end of the season, with its beautiful autumn foliage in shades of brown. Its funnel-shaped flowers, whose sweet scent is most noticeable in the evening, bloom in small clusters that renew throughout the summer if the plant does not lack water. Its rambling stems wrap around any support, climbing a pergola, a trellis, or a large bush. Continental gardeners will have no trouble growing it in a large pot on the terrace or balcony, as long as they store it away in winter.

The Chilean jasmine is a rambling climbing plant with a tuberous root from the Apocynaceae family. It is related to Trachelospermum, periwinkles, Alamanda, and Dipladenia, the summer glory of our flowering pots. It is naturally present from southern Bolivia and Ecuador to northern Argentina and Chile. The hardiness of a mature plant is estimated at -8, or even -10°C (14°F) at the lowest without winter protection, with the plant regrowing from the stump if the aboveground vegetation has been destroyed. Some sources claim it can regrow after a brief freeze of -12 °C (10.4°F) (late at night).

The Mandevilla suaveolens grows quite rapidly, producing long flexible stems that lignify quickly, with its vegetation eventually covering about 3.50m (11ft) or even 4m (13ft) in all directions in open ground and a favourable climate. The branches are adorned with pairs of opposite leaves, 6 to 7cm (2 to 3in) long, with a slightly undulated entire blade shaped like an elongated ace of spades or heart. Their colour is a matte medium green. Before falling, late in autumn, the foliage takes on shades of brownish-orange, a rather unusual colour that stands out in the garden. The foliage remains evergreen in winter if temperatures do not drop below -5°C (23°F).

The very long flowering period begins in early June and does not end until September-October. The flowers, which stand out well from the foliage, are gathered in clusters of funnel-shaped 8 to 12 white flowers with a diameter of 5cm (2in). They open successively or in groups of 2 or 3 at a time. Their scent can be detected several metres away, especially in the evening. This flowering, which attracts pollinating insects, gives way to green fruits that resemble two green beans joined at their ends. They contain numerous seeds with bristles. Like many plants in the Apocynaceae family, the Chilean jasmine contains alkaloids that are toxic to humans.

Mandevilla laxa is one of the most exciting climbers in mild regions: it perfumes summer evenings while preserving winter sunlight on the patio. To surround it, imagine Mexican orange trees, shrubby lavenders, and ceanothus creeping. You can also make it climb on a small tree or a trellis against an exposed wall. Or even on a pillar, a post. Its branches will intertwine with those of clematis, honeysuckle, or climbing Solanum in mild climates.