Totally eclipsed by their perennial cousins, annual nemesia are still lovely

Much of last summer was spent writing a book on container gardening. Due out in spring it is supposed to be clear, concise and easy to understand for beginner gardeners. It sounds like an easy write. But trying to be concise, in limited space, when the plant in question actually needs a lot of explanation is not easy, indeed it is not always possible. It was a good exercise in cutting the waffle but there were some plants that I really struggled to ‘slot into boxes’. A lot of those were plants that are perennials but treated as annuals. Take osteospermums as an example. Most people buy them in late spring, put them in pots and then through them away the following April when they think about gardening again. While it is true that they are perennials, can be propagated from cuttings, can be kept another year in frost-free conditions, and may survive outside in a sheltered spot, how do you explain that to a beginner without causing utter confusion! It is like when I ask for directions; the worst answer is, ‘well you can turn left then right then left again or you could go right, take the seventh left and straight on or you could…’ Please – just tell me one way!

All this preamble has a slight relevance because nemesias have changed. When I started gardening it was easy, they were half hardy annuals with flowers in tutti-frutti colours that were brighter and more cheerful than virtually any other bedding plants. We sowed in March, pricked out into wooden trays 6×8 and they flowered in July and August. When they were past their glorious best we would shear them off to deadhead them, give them a soak and they would flower again.

But, in the past two decades, a host of new nemesias, based on N. denticulata, have been bred and these are perennials. The first were in shades of blue and lilac, usually scented, but the colour range has increased to now include the reds, yellow and orange of the annual kinds. They are fabulous plants, often flowering all summer if they are sterile, and some smell fantastic. When we had the display at Bloom in Dublin I would always include ‘Wisley Vanilla’ and we would sell out of the plants within the first two days, no matter how many we took for sale, based on their scent alone.

The annual kinds do not usually smell, at least I do not recall it, but N. cheiranthus, which goes by many variety names but are all the same, has a distinct coconut smell as well as curious and charming yellow and white flowers. The standard annuals are N. strumosa. A few years ago the blue and white ‘KLM’ was very popular but seems to be disappearing.

This would be a great shame. The new perennials are fabulous plants but, costing several euro a plant, are unsuitable for border planting. But from seed you can be generous with your drifts and have a really bright splash. Most grow to about 25cm in bloom and while they are not exactly statuesque, they have a cheeky charm. Best of all is the range of colours from a good mixture. They are not tricky to grow from seed as long as you watch for overwatering when they are young, something that is true of the perennials as well.

how to grow nemesia