Matthiola longipetala. Spindly and insignificant by day, it is potently fragrant at dusk! Single, four-petalled flowers are a pale lilac. Best grown either in out-of-the-way spots or with Virginian Stock to combine their complimentary growing habits, colours, and fragrances. Shear back once for continuing scent from July until frost. Stocks prefer cool temperatures, but need…