Amazing annuals: Nicotiana
These varied, often fragrant plants include annuals and shrubs and are definitely addictive.
OK, so let’s get the obviously bad one out of the way! Nicotiana tobaccum is a large, leafy annual, reaching 2m high, with not-unattractive, pink flowers and leaves that contain a natural pesticide to repel insects. It is the source of tobacco, though other species, such as the green-flowered N. rustica have also been smoked.
Now we have that out of the way we can consider other species, grown primarily for ornament. The first I ever grew were N. affinis hybrids in various colours. I am pretty sure they were ‘Sensation Mixed’, named because the flowers remained open during the day. Traditionally N. affinis opens its flower in the evening and they wilt and look shabby during the day. It is a minor problem with some nicotiana anyway but hot days that cause midday wilting are sadly rare here. Nicotiana affinis is naturally white but the use of other species has increased the colour range to include crimson, lilac, purple, pink and green. This plant, with various-coloured flowers is called N. x sanderae. These colours are quite pastel and nicotiana are generally rather subdued. White and green are definitely dominant colours among the species.
There are 40 or so species in the wild, mainly from the Americas and the southern hemisphere including Australia. They are in the Solanaceae, the same family as potatoes, tomatoes, aubergines and henbane and nightshades. More importantly they are related to daturas, brugmansias, salpiglossis and petunias. By the way, the genus is named after Jean Nicot, the French Ambassador to Portugal who sent seeds of tobacco to France in 1560. Tobacco is native to the Caribbean so presumably reached Portugal sometime after Columbus. They are not named after nicotine, but both are named after him. I know that it doesn’t matter how you pronounce botanical names as long as you are understood but I always wince a bit at ‘nicotina’. Since jean Nicot was French and, presumably the terminal ‘t’ is silent, I am happier with ‘nicoh she arna’ than ‘nicot ee arna’. It is only a thought since there is no way I am going to call dahlias as they should be, named after Mr Dahl – as in Roald Dahl – I would sound too much like the Queen.
If you are prepared to tolerate subtle, then there are no ugly nicotianas. I have previously mentioned some nicotiana including the fabulous N. mutabilis. I am sure that the ‘Whisper’ nicotianas (below) are close to, if not identical to, this Brazilian species. It grows to 1.5m, can be perennial in mild winters and has lovely flowers that open palest pink and deepen as they age, to crimson. Many nicotiana are potentially perennial in our gardens. The deservedly popular N. sylvestris, often sold as ‘Only the Lonely’ though I have no idea why since I think it is just the plain species, has a strange habit. At first you get alarmingly large, paddle-shaped leaves in a lush rosette and then, when it is ready, it sends up a tall stem with clusters of long-tubed, drooping, white, fragrant flowers. It too can be perennial. It is worth sowing early and giving it a good start so that the plants are big and leafy before they start to bloom if you want tall stems – starved plants will only make weedy, short stems.
Another perennial, that is an invasive weed in some countries, is Nicotiana glauca. This is a shrub with slender stems and hairless, non-sticky, blue-green leaves. It can reach 3m or more but will only reach about 1.5m in a summer if sown in spring, before it is killed by frost. Anyone reading this where N. glauca is a weed, thriving in dry spots and among rubble (it is common around the Med and the Canaries) will wonder why anyone would want to grow it, but it is a slender and attractive plant for a sunny border or patio even without the pretty (unscented) yellow flowers.
Others worth a try are the green N. langsdorfii, famed for its blue pollen, though it is a subtle plant. Two years ago I grew N. suaveolens with dainty white flowers – a pretty and delicate plant with decent perfume. I also grew the Australian N. excelsior which was a strange one with lush green leaves and soft prickles. The abundant flowers were a little small for the size of the plant but very pretty and fragrant.
For a while, breeders seemed obsessed with making nicotiana as dwarf as possible, as though they were going to replace impatiens. But then downy mildew appeared and a couple of wet years made them less popular. Whether it was the compact, congested habit that prevented air circulation and encouraged the disease, I do not know. But I have rarely had the problem on any of the taller kinds and species. In recent years breeders have become more adventurous and realised that not everyone wants big, bright flowers on tiny plants. A lot of brownish shades have been introduced to N. langsdorfii-type plants and this species is supposed to be a parent of the dainty, white ‘Starlight Dancer’ which I grew last year.
But don’t let any of this species snobbery put you off the colourful mixes of N. sanderae the common bedding nicotiana. These are easy to grow, flourish in sun or part shade and, if you avoid the dwarf kinds, are substantial enough to be useful in mixed borders. Sow the seeds in March. The seeds are small and need light to germinate. Sow them on the surface of clean compost that has been watered, with clean water, and cover with a little perlite and keep at about 20c to germinate. The seedlings are usually tiny and you need to leave them to grow a few true leaves before attempting to transplant them. Water carefully at first but once they start to grow they increase in size rapidly ready for planting out in late spring, after the last frost.
Nicotiana tobaccum is one that I have never seen before . . . but would like to. Nicotiana glauca is annoying in some places, particularly farther south. It looks shabby at its best, and then leaves all the shabby canes to be cleaned up over winter.