How to grow Incarvillea
Commemorating Pierre d'Incarville (1706-57), a French Jesuit missionary to China (Bignoniaceae). A genus of about 6 species of herbaceous perennials, first introduced in the mid-nineteenth century, hardy or nearly hardy in suitable conditions.
Species cultivated I. delavayi, 2 feet, rose-pink trumpet shaped flowers in May and June. I. grandiflora, 14 feet, large, deep rose-red flowers with orange tube, and throat blotched white, June-July ; var. brevipes, a variety with crimson flowers. I. olgae, 2-3 feet, somewhat shrubby, with clusters of pale pink flowers and finely divided foliage, summer.
Cultivation A light, well-drained warm soil in a sunny but sheltered border is essential. Cold, stagnant moisture is fatal. Plant in March or April, and protect the crowns with bracken in winter. Liquid manure applied occasionally during the summer is beneficial. Propagation is by division of large plants in autumn or by seed in heat in March, or in a cold frame in April, transplanting outdoors in June. Seedlings may take 3 years to reach flowering size.