Hesperis Matronalis The Hesperis matronalis or Sweet Rocket is a Hardy Biennial which although short lived, freely self seeds in the wildlife or cottage garden. The charming tall spikes hold sweet spicy fragrant lilac & violet flowers with a delicious evening fragrance in late spring. The Hesperis matronalis is very attractive to butterlies, moths, bees & other beneficial insects with its nectar rich flowers. This is a must in the wildlife garden, seeding readily in drifts. Plant with Brunnera, Digitalis or ferns for a natural display. The plants are clump forming. Height up to 90 cm, spread 40cm.