Delaware Nature Guide: June 2026
June settles Delaware into early summer — the migration over, the breeding season in full swing, and the first summer fruit reaching the markets. The marshes are loud with nesting birds, the meadows fill with flowers and butterflies, and the long, warm days carry the coastal-plain landscape toward high summer.
What to look for this week
- Tens of thousands of snow geese crowd the Bombay Hook impoundments, rising in roaring white clouds — the heart of Delaware's winter waterfowl spectacle.
- The Quadrantid meteor shower peaks in a short, sharp burst around January 3; watch the northeast after midnight from a dark Cape Henlopen or lower-Sussex site.
- A kitchen-table planning week — order seeds and sketch beds, leaving any snow banked over perennials as insulation against the coastal-plain freeze-thaw.
- American holly, the state tree, stands glossy and red-berried through the bare coastal-plain woods, the signature green of the Delaware winter.
Birds This Month
June in Delaware is the breeding season at its height. The migrants have passed and the resident and summer birds are nesting and singing: indigo buntings, blue grosbeaks, orchard and Baltimore orioles, eastern kingbirds, yellow warblers, common yellowthroats, and field sparrows hold territory in the fields and edges, while the swamp woods ring with prothonotary warblers, Acadian flycatchers, and wood thrushes. Ospreys are feeding young on the bay-shore platforms, and bald eagles' chicks are nearly grown.
The tidal marshes of Bombay Hook and Prime Hook are busy with nesting clapper rails, willets, seaside and saltmarsh sparrows, marsh wrens, and colonies of great, snowy, and cattle egrets, glossy ibis, and black-crowned night-herons. At Cape Henlopen, piping plovers and least terns nest on the protected beaches. Chuck-will's-widows and whip-poor-wills call from the southern woods at dusk.
This month's tip: walk the marsh edges at dawn to hear the dense chorus of breeding birds, and give the roped-off beach-nesting areas at Cape Henlopen a wide berth — the piping plover and tern colonies are fragile and easily disturbed.
What's Blooming
June turns Delaware's flowers from the woodlands to the meadows, marshes, and roadsides. The summer wildflowers open: butterfly weed blazes orange in the dry sandy fields, common and swamp milkweed begin their fragrant pink bloom, black-eyed Susan, daisy fleabane, and oxeye daisy brighten the old fields, and spiderwort and wild bergamot appear at the woodland edges. Blue flag iris and swamp rose bloom in the wet meadows.
Along the coast and in the Sussex woods, the season has its own cast: the native swamp azalea and sweetbay magnolia perfume the damp woods, pickerelweed spikes blue in the freshwater ponds and ditches, and the dunes carry seaside goldenrod foliage and the white of beach plum gone to fruit. Elderberry froths white along the wet roadsides, and the first day-lilies open. The Delaware landscape shifts into its full, warm summer character, the meadows humming with insects.
Garden This Month
June is high-growth time in the Delaware garden. Keep planting warm-season crops — there is plenty of season left for more beans, cucumbers, summer and winter squash, and corn, and sweet potato slips can still go in early in the month. Succession-sow beans, corn, and basil, and start seeds of fall brassicas like broccoli and cabbage indoors or in a nursery bed for transplanting in midsummer. The first tomatoes, peppers, and squash set fruit, and the spring crops finish.
Watering becomes the central task as the heat and humidity climb — give beds a deep, regular soak, especially newly set transplants, and mulch heavily to conserve moisture and keep the coastal-plain soil cool. Stake and prune tomatoes, pinch back basil, and harvest squash, cucumbers, and beans young and often to keep the plants producing. Stay ahead of the summer pests now arriving in force: Japanese beetles, squash bugs, cucumber beetles, and tomato hornworms. Deadhead annuals and roses, and watch for the first signs of the fungal diseases that thrive in Delaware's humid summers. The garden is lush and demanding now.
Zone 7b (Kent, Sussex, and the coast): in the warm lower counties the heat builds fast — mulch deeply, water consistently, and set out the last sweet potato slips and a fresh round of beans and cucumbers for late-summer harvest while the long season still allows it.
What's at the Farmers Market
June markets in Delaware brim with early summer. Strawberries finish their season early in the month, overlapping with the arrival of the first blueberries, sweet cherries, and raspberries. The vegetable stands fill with peas, snap beans, summer squash, zucchini, cucumbers, new potatoes, beets, carrots, broccoli, and the first tomatoes from hoop houses, alongside abundant lettuces, Swiss chard, and salad greens before the heat slows them.
From the Delaware Bay, blue crabs come into their summer season — choose live, lively crabs that feel heavy for their size, keep them cold and damp under wet burlap, and cook them the day you buy. Choose berries that are fully colored and fragrant and use them quickly, keeping them dry and refrigerated unwashed. Pick squash and cucumbers that are firm and glossy and on the small side, and beans that snap crisply. Local honey, eggs, and cut flowers round out a market at its lush early-summer best.
Night Sky This Month
June carries the shortest nights of the year around the summer solstice, so dark time is brief, but the summer sky arrives in full. The Summer Triangle — brilliant Vega in Lyra, Deneb in Cygnus, and Altair in Aquila — climbs the eastern sky, and the great curve of Scorpius, led by red Antares, scrapes low across the southern horizon. Between them, the rich star clouds of the Milky Way begin to rise, densest toward the teapot of Sagittarius and the heart of the galaxy.
There is no major meteor shower in June, so this is a month for the deep-sky riches of the summer Milky Way: the globular cluster M13 in Hercules rides high overhead, and a small telescope sweeps up clusters and nebulae along the rising galactic band. The warm, short nights are comfortable for observing. Seek the darkest skies at Cape Henlopen and the lower Sussex coast, looking south and east over the bay and ocean away from inland light.
Exact planet positions vary year to year — the printable Delaware night-sky guide carries this year's details for your part of the state.
Butterflies & Pollinators
June butterflies are abundant across Delaware. The swallowtails remain on the wing — eastern tiger, spicebush, black, and zebra — and the summer brushfoots fill the meadows: great spangled fritillaries nectar at milkweed and bergamot, pearl crescents, red admirals, painted and American ladies, common buckeyes, and red-spotted purples patrol the field edges and trails. The hairstreaks appear — banded, coral, and gray hairstreaks — and the small skippers explode in number across the grasslands.
The monarchs that arrived in May are now breeding, and June's milkweed carries eggs, striped caterpillars, and the first fresh locally raised adults of the summer. In the Sussex woods and pine edges, watch for the summer azure and the showy eastern tailed-blue in the clover. This is a fine month to watch the full life cycle on the milkweed — egg, caterpillar, chrysalis, and adult — unfolding in a Delaware garden, and to keep nectar flowers blooming for the busy meadow fauna.
Trees This Month
By June Delaware's trees are in full, dense summer leaf, and the flowering shifts to the latest bloomers and the first fruit. American holly finishes its small white flowers, setting the green berries that will redden by winter, and the sweetbay magnolia opens its lemon-scented creamy flowers in the damp coastal-plain woods, a fragrant signature of the Delaware summer. Southern catalpa hangs its showy white flower clusters, and the chestnut oaks and black gum bloom inconspicuously.
The early fruit forms: red maple and elm samaras have fallen, mulberries ripen dark and drop along the edges, and the serviceberries and wild cherries set fruit for the birds. The loblolly pines of Sussex have finished their pollen and hardened their new growth, and the bald cypress of Trap Pond stands in full feathery green over the dark swamp water. The canopy is at its thickest and shadiest, the woods deep and humid in the building summer heat.
Go deeper with the Delaware guides
The complete Delaware birding, native-plant, wildflower, and night-sky guides — or the whole year in one bundle.
Same month elsewhere: June in Washington, D.C. · June in Florida · June in Georgia