I’ll bet this is not a plant you would ever previously thought I’d be likely to recommend. However wait, yes petunias can be a bit cheap and nasty, but they do have certain virtues other than the exuberant floriferousness they always exhibit. Too long associated only with garish town centre bedding schemes and pub frontages. In almost every hanging basket, tub, pot, churn and recycled wheelbarrow these are still an interesting genus. Related to the potatoes and tomatoes Petunias belong to the Solanaceae family so the foliage and most parts are probably poisonous. Of a dozen or so species one important parent of our popular bedding plants is P. violacea also called Nierembergia phoenicea. This short lived perennial only arrived in Britain in 1831. It came from South America, thus the lack of hardiness. It’s purple tubular blooms were admired but it was small; only a hand or so high. So it was crossed with others to get our more vigorous modern beauties. However it had a great virtue only retained in a few of the modern hybrids. It was gloriously scented with a vanilla like fragrance especially strong at night. Fortunately if you gather a range of purple and white varieties of modern strains you’ll find many carry this beautiful scent.
If you also grow them under cover; their perfume is concentrated, and the extra warmth brings it out on more evenings filling the whole conservatory or greenhouse. And even better, given a frost free place the plants just ramble on blooming right thro’ winter bringing much needed cheer to the dim days of winter. (Watch out for mealy bug infestations and mould.) Once you have found your favourite variety take cuttings in spring and grow fresh plants as although old ones can serve another year or two new ones flower the better. Almost any piece will root in gritty compost and some bottom heat. (It helps to nip off lower leaves and any flower buds before
rooting.) Later pot up into rich compost, but do not feed heavily if at all once flowering size is reached as excess nitrogen produces soft rank growth and poorer perfume. In the border under cover plants get more and more magnificent as the rain never spoils them. Propagate loads and put them out after the frosts and in a hot summer you can fill your whole garden with their scent.