What is the best hardiest most fragrant annuals I could grow in masse with a long season? (I know, I'm asking for a miracle plant but anything that comes remotely close?)
You probably need to plant a mix to get what you really want. Matthiola bicornis is not the showiest plant, but extremely night fragrant and blooms all summer to frost. (Mine from last year just put forth its last flower a few weeks ago!) Nicotiana is another good one, several kinds, fragrant, long season.
Is matthiola biscornis the "correct" name for night scented stock Eric? I love what I know as night scented stock because it smells beautiful, self seeds and while not showy is very dainty and whispy. What about another favourite of mine, members of the wallflower family? Margaret
Honey-scented sweet alyssum (Lobularia maritima) can also be easy and willing, even reseeding for years in some spot so that it almost has the effect of a perennial planting.
Yes alyssum is a good one, easy to grow. Wallflowers (Erysimum species and cultivars) do well here. Some are perennial (short lived). Yes Matthiola bicornis is night scented stock. The regular stock is very fragrant as well, easy to grow, but does not have a long bloom period (there may be some superior cultivars on the market that last longer.) Another annual with intense fragrance that I have grown is Zaluzianskya - Z. capensis is the easiest to grow. The fragrance is amazingly strong and wonderful.