In Cornwall’s early summer, Large White butterflies visit purple Honesty blooms for nectar, their flights peaking with the plant’s flowering. Mild climates, cottage gardens, and nearby crucifers strengthen this seasonal garden partnership.
In early summer Cornwall, gardens hum with pollinators. Among the most visible is the Large White butterfly (Pieris brassicae), drifting between flower heads with crisp white wings that flash in the sunlight. Its bold black wingtips set it apart from the smaller “cabbage whites” of the same family. Females carry an extra signature — two distinct black spots on the upper forewings — while males are more simply patterned. With a wingspan of 5.8 to 6.3 cm, the Large White is a commanding presence in the air, its steady flight tracing a path through gardens, allotments, farmland, and wildflower-rich community spaces.
This butterfly is common throughout Cornwall from April to October. In warm years, the first brood of adults often appears from late April, peaking through May and into mid-June. Its adaptability is part of its success: it thrives in urban gardens and cottage borders, open countryside and allotments, and even coastal grasslands where salt wind meets sheltered hedgebanks. In all of these, a mix of nectar-rich plants and cruciferous foliage ensures both adults and caterpillars can find what they need.
One flower seems to fit the Large White’s early summer perfectly — Honesty (Lunaria annua).
Honesty flowers from April to June in Cornwall, producing generous clusters of purple or, more rarely, white blooms. Its nectar is easily accessed by butterflies with long tongues, and it is a magnet for not just Large Whites, but also Orange-tips and Green-veined Whites. In gardens, Honesty is primarily a nectar source for adult Large Whites. It can host eggs and larvae, but generally only incidentally, far less often than cabbages, nasturtiums, or other widely-grown crucifers. When it does happen, it is usually in lush, mixed plantings where conditions are sheltered and damp.
The timing is more than coincidence. Honesty’s peak flowering coincides with the emergence, feeding, and breeding of the Large White’s first brood. Fresh nectar fuels the adults, while the foliage remains available should females choose to use it for egg-laying. In long-flowering stands, this link can stretch further: in good Cornish summers, the final weeks of the first brood may overlap with the earliest of the second brood, extending Honesty’s role as a feeding plant well into early July.
The Large White’s year is shaped by two, sometimes three, broods. First-brood adults appear from late April in warm years, more typically from May, and fly until mid-June. Females lay their eggs in clusters of 20 to 100, most often on the leaves of cabbages, kale, nasturtiums, and wallflowers, with Honesty as a less frequent choice.
The caterpillars hatch in two to three weeks and feed in groups, their combined appetite capable of defoliating plants — although in many Cornish gardens, their numbers are kept in check by parasitic wasps and hungry birds. When fully grown, they leave the host plant to pupate on garden walls, stems, or fences. In summer, the pupal stage lasts about two weeks before the next generation takes wing.
The relationship between Large White and Honesty is especially strong in Cornwall for several reasons:
When Large Whites do choose to breed on Honesty in Cornwall, several conditions tend to be in place:
The success of this pairing depends on the two life cycles aligning. In mild springs, Honesty flowers earlier and for longer, and Large Whites emerge sooner, often in late April. Cool or late springs delay both, sometimes shortening the period when nectar and butterflies overlap. Adequate rainfall keeps Honesty blooming and its leaves soft for caterpillars, while spring droughts can reduce nectar availability and leaf quality. Extreme weather — late frosts, storms, high winds — can damage blooms and hinder butterfly activity, breaking the synchrony.
The Large White is sometimes maligned as a brassica pest, yet in Cornwall’s gardens it is also a valuable pollinator, visiting a wide variety of flowers. Honesty, in turn, contributes more than just nectar in spring: its silvery seed pods catch the low light of autumn and winter, providing texture and shelter in the garden’s quieter months.
To encourage this seasonal connection:
When the Large White drifts across a stand of purple Honesty in a Cornish cottage garden, it is more than a pretty picture. It is a moment shaped by climate, tradition, and the gardener’s hand — a brief season where plant and pollinator meet at their peak, each benefiting from the other, and together adding to the richness of Cornwall’s summer gardens.
The Large White (Pieris brassicae) is one of Cornwall’s most familiar butterflies, known for its crisp white wings, strong flight, and its appetite for brassicas. Often called the “cabbage white,” it is both a resident species and a migrant, with some autumn broods boosted by arrivals from continental Europe. From spring to autumn, it is a common sight gliding over gardens, allotments, and countryside.
Everyday Encounters
Wild Cornwall
The Large White may have a reputation as a “garden pest,” but in flight it’s a striking and graceful insect, and its migrations connect Cornwall to a wider European story. Its wide range means you can enjoy watching it almost anywhere — from ornamental borders alive with nasturtiums to windswept coastal fields — while its life cycle offers an intimate glimpse into the balance between abundance and the natural checks that keep it in harmony.
