I discovered this great little plant a coup,e of years ago. The local garden centre was selling a new variety called 'Wisley Vanilla' as a bedding plant. It was well named: the flowers were small, a lovely rich cream colour. One sniff and I was revelling in the heavenly scent of Vanilla ice cream. I Was sold and bought three plants on impulse.
The plants did very well in tubs on a sun trap patio. Fully grown they were about a foot round and high although the biggest one was almost 50cm wide. A mass of tiny flower heads covered the plants and the smell was amazing especially in the evening. They lasted all through the summer as the soil was always kept damp (not soaked).
I let them die back in the autumn and cut the dead stems back to an inch above ground level. The following spring the pots were full of self seeded new nemesias which were dig up and put all over our small garden.
By now, I wanted more and actively looked for them in garden centres. I found a variety call Berries and Cream: flowers were a lovely blue/purple fading into rich cream towards the centre. And the smell???? Like Raspberry pavlova. It was so good I could have eaten them.
There are lots of different varieties around in all colours so my advice would be to do some research before buying. You can get Nemsias as plant cell seedlings or as ready to go bedding plants. They are both pretty easy to grow. I tried raising them from see last year but had some patchy results. I used a seed tray in the greenhouse but would probably have better results with a propagator. Germination was about 50% although the seedlings did well once finally up.
Would I recommend them? Absolutely . Stunner of a border plant in a myriad of colours and scents. And they come back year after year.