Viola

All these hardy violets are easy to cultivate in a sunny, but cooler spot or in part shade, The V.cornuta types being especially useful for providing early summer ground cover amongst emerging perennials such as hosta. All should be trimmed back after flowering usually by late summer, to refurnish with foliage and sometimes a second crop of flower. Keep well watered in dry spells and especially if growing in containers.

Viola flowers have a spur, sometimes very long as in V. cornuta, within which is located the nectar; bees and flies are the main visitors, with different species reflecting the different spur-lengths. Late in the flowering season, some species produce non-opening ('cleistgamous') flowers that pollinate themselves internally to ensure seed-production: it is thought the diminutive nature of the plants may make it difficult for pollinators to find them. The seeds themselves have an oil-body attached that attracts ants (a vital component of any healthy garden) - the ants remove the whole fruit to their nest where they eat the oil body, thus dispersing the seeds. The foliage of some species at least (including V. riviniana) is the sole foodplant of several fritillary butterflies, at least one of which (silver-washed fritillary) is now a realistic hope for attracting to a garden in England especially, following its recent range expansion.