In contrast alternative planting for the summer Holly Blue butterfly brood includes Bramble, Rubus fruticosus, Alder Buckthorn, Frangula alnus , Common Buckthorn Rhamnus cathartica, also known as Purging Buckthorn and Gorse, Ulex ssp..
Gorse is in fact the only plant used by both broods of Holly Blue, which admittedly isn’t always top of a gardeners list, however a mixed native hedge, hedgerow or shrubby mini-copse or corner containing Buckthorn, Dogwood and Spindle will serve both Holly Blue generatons well and sustain the entire annual cycle of Holly Blue butterflies.
Less Common Caterpillar Host Plants
The non-native, but attractive Snowberry bush, Symphoricarpos spp has also been used by the second Holly Blue brood.
General Caterpillar Host Planting Tips
Caterpillars usually rely on our native wildflowers for evolutionary reasons, which often may not be readily available in your local general garden centre and when they are, may not be the original native cultivar or pesticide free (even with a pollinator friendly label so do take care to ask). The good news is that there are plenty of excellent specialist native plant and seed stockists online, a few of which are listed below.
Plant your caterpillar host plants in generous clumps as butterflies are often quite picky about which stems they will use. Site them in or near a sunny sheltered position (depending on the plants’ requirements) ideally with a good, seasonally appropriate, source of nectar close by. Again native plants are often preferred, when using non-natives pick single flowered varieties rather than doubles as the latter produce less nectar.
Companion Holly Blue Butterfly Nectar Plants
Most of the Holly Blue’s caterpillar host plants serve as nectar sources and honeydew is also used, but these pretty wildflowers are also a good companion planting option:
Spring Brood
Ajuga reptans, Bugle
Ranunculus spp, Buttercup
Selene dioica, Red Campion
Myosotis spp., Forget-me-not
Anthriscus sylvestris, Cow Parsley
Summer Brood
Eupatorium cannabinum, Hemp Agrimony
Carduus spp. and Cirsium spp., Thistles
Mentha aquatica, Water Mint
Ligustrum vulgare, Wild Privet
British Native Wildflower Stockists
There are plenty of online specialist suppliers these days, do ask about pesticides and double check latin names before ordering.