Many butterflies are very specific about which host plant they will lay their eggs on. Sometimes they seek out plants in a particular family, and sometimes their caterpillars will dine on one plant and one plant only. If you intermingle attractive host plants with nectar rich plants in your flower garden, you may find yourself fostering one butterfly generation after the next. Don’t worry about extensive caterpillar damage on your host plants; unlike some caterpillars that are voracious garden pests, butterfly caterpillar feeding rarely causes death or stunted growth on healthy host plants.
Aster flowers are an important source of nectar for migrating butterflies in the fall, but before that, the larvae of the pearl crescent butterfly feed on its foliage. Asters often appear alongside mums in fall nursery offerings, but asters aren’t related to mums. Unlike mums, you can find many blue varieties of asters, and asters have a greater hardiness to freezing temperatures than mums.
Monarchs depend on butterfly weed and other plants in the milkweed family to provide them with the toxins that make them unpalatable to birds and other predators. True to its name, butterfly weed is very easy to grow, but it does demand soil that drains quickly. Plant this perennial where it can have a forever home, for its large taproot makes transplanting difficult.
3. California Lilac
Gardeners in warm coastal areas depend on the drought tolerant, evergreen California lilac shrub to add structure, beauty, and a windbreak to their seaside gardens. In addition to enjoying the deep blue flowers of this shrub, you will be providing fodder for the larvae of the California hairstreak.
The painted lady, gray hairstreak, and some skippers use the hollyhock as a host plant for their larvae. Many hollyhocks are biennial, so expect them to produce foliage the first year, and flowers the second season. Plant seeds two years in a row to ensure some plants in each stage of growth for flowers every year.
The small Boisduval’s blue butterfly doesn’t go far from a source of food for its larvae, the lupine plant. The larvae eat the flowers and seedpods of the lupine, not just the foliage. Ecologically minded gardeners should watch for rare and endangered subspecies of this butterfly, such as the mission blue, in their garden.
The widely distributed grey hairstreak butterfly isn’t picky about host plants for its larvae; it enjoys mallow among the dozens of vegetable and ornamental plants it lays eggs on. Larvae of the painted lady and common checkered-skipper also feed on mallow plants. Plant the popular ‘Zebrina’ mallow plant in your sunny zone 5-9 flower garden, where it will bloom from late spring until early fall.
You can decide if the cabbage white butterfly is friend or foe; your answer may depend on whether you grow cruciferous vegetables like cabbage and broccoli in your garden. In addition to these host plants, the cabbage white will lay eggs on the low maintenance annual nasturtium plant.
The showy zebra butterfly, a Florida and Texas resident, feeds its babies exclusively on the foliage of the passionflower. The Gulf Fritillary also eats passionflower foliage. Gardeners should shop carefully for passionflowers, as many will not survive freezing temperatures. The common maypop (Passiflora incarnata) will survive temperatures down to 20 degrees F.
9. Queen Anne’s Lace
The conspicuous striped larvae of the black swallowtail butterfly aren’t difficult to spot on the lacy foliage of Queen Anne’s Lace and other plants in the carrot family, like parsley and dill. This wildflower looks best in naturalized meadow plantings.
In addition to dining helpfully on weeds like the plantain, the larvae of the common buckeye will snack on the foliage of your snapdragons. Snapdragons are a cool weather annual, and you can plant them outdoors three weeks before your average last frost date.
11. Sweet Pea
If you reside in the Eastern half of the United States, you may attract the iridescent Eastern tailed-blue to your garden with a host planting of sweet peas. Sweet pea vines will shut down when temperatures rise above 85 degrees F, so start your seeds indoors and set out transplants when soil temperatures average 60 degrees for the longest blooming season.