Quick answer: 151 native Delaware plants have a recorded bloom range that includes May.
151 species
- Adam's needle Yucca filamentosa · 21 states
- Allegheny chinquapin Castanea pumila · 21 states
- Allegheny serviceberry Amelanchier laevis · 17 states
- American alumroot Heuchera americana · 20 states
- American basswood Tilia americana · 37 states
- American beech Fagus grandifolia · 31 states
- American bittersweet Celastrus scandens · 33 states
- American bladdernut Staphylea trifolia · 28 states
- American cranberry Vaccinium macrocarpon · 15 states
- American hazelnut Corylus americana · 34 states
- American holly Ilex opaca · 28 states
- American hornbeam Carpinus caroliniana · 33 states
- American plum Prunus americana · 37 states
- American strawberry bush Euonymus americanus · 23 states
- American wisteria Wisteria frutescens · 14 states
- Atlantic white cedar Chamaecyparis thyoides · 17 states
- Balsam poplar Populus balsamifera · 8 states
- Beach plum Prunus maritima · 8 states
- Bear oak Quercus ilicifolia · 13 states
- Bearberry Arctostaphylos uva-ursi · 34 states
- Birdfoot violet Viola pedata · 34 states
- Black cherry Prunus serotina · 35 states
- Black huckleberry Gaylussacia baccata · 25 states
- Black locust Robinia pseudoacacia · 12 states
- Black oak Quercus velutina · 30 states
- Black tupelo Nyssa sylvatica · 31 states
- Black walnut Juglans nigra · 33 states
- Black willow Salix nigra · 24 states
- Blackjack oak Quercus marilandica · 24 states
- Box huckleberry Gaylussacia brachycera · 8 states
- Bristly locust Robinia hispida · 10 states
- Broadleaf cattail Typha latifolia · 39 states
- Bur oak Quercus macrocarpa · 33 states
- Butterflyweed Asclepias tuberosa · 40 states
- Butternut Juglans cinerea · 26 states
- Canada wild rye Elymus canadensis · 37 states
- Canadian serviceberry Amelanchier canadensis · 21 states
- Canadian wild ginger Asarum canadense · 30 states
- Cardinal flower Lobelia cardinalis · 41 states
- Carolina allspice Calycanthus floridus · 17 states
- Chokecherry Prunus virginiana · 44 states
- Cinnamon fern Osmunda cinnamomea · 32 states
- Climbing prairie rose Rosa setigera · 27 states
- Cockspur hawthorn Crataegus crus-galli · 25 states
- Common blue violet Viola sororia · 37 states
- Common elderberry Sambucus nigra ssp. canadensis · 36 states
- Common hackberry Celtis occidentalis · 33 states
- Common hoptree Ptelea trifoliata · 28 states
- Common leopardbane Arnica acaulis · 10 states
- Common ninebark Physocarpus opulifolius · 30 states
- Common persimmon Diospyros virginiana · 26 states
- Common selfheal Prunella vulgaris · 25 states
- Common winterberry Ilex verticillata · 32 states
- Common yarrow Achillea millefolium · 47 states
- Coral honeysuckle Lonicera sempervirens · 16 states
- Coralberry Symphoricarpos orbiculatus · 30 states
- Creeping phlox Phlox subulata · 23 states
- Deerberry Vaccinium stamineum · 22 states
- Downy serviceberry Amelanchier arborea · 37 states
- Dutchman's breeches Dicentra cucullaria · 32 states
- Eastern bluestar Amsonia tabernaemontana · 18 states
- Eastern hop-hornbeam Ostrya virginiana · 37 states
- Eastern leatherwood Dirca palustris · 25 states
- Eastern red cedar Juniperus virginiana · 37 states
- Eastern red columbine Aquilegia canadensis · 36 states
- Eastern redbud Cercis canadensis · 32 states
- Eastern smooth beardtongue Penstemon laevigatus · 15 states
- Eastern white pine Pinus strobus · 28 states
- Fire pink Silene virginica · 26 states
- Flowering dogwood Cornus florida · 31 states
- Foxglove beardtongue Penstemon digitalis · 35 states
- Fragrant sumac Rhus aromatica · 30 states
- Golden alexanders Zizia aurea · 35 states
- Gray dogwood Cornus racemosa · 19 states
- Green ash Fraxinus pennsylvanica · 43 states
- Heart-leaved meadow parsnip Zizia aptera · 30 states
- Highbush blueberry Vaccinium corymbosum · 25 states
- Honey locust Gleditsia triacanthos · 13 states
- Indian blanket Gaillardia pulchella · 17 states
- Indigo bush Amorpha fruticosa · 37 states
- Jack-in-the-pulpit Arisaema triphyllum · 35 states
- Jacob's ladder Polemonium reptans · 31 states
- Lanceleaf coreopsis Coreopsis lanceolata · 35 states
- Low prickly pear Opuntia humifusa · 31 states
- Lowbush blueberry Vaccinium angustifolium · 22 states
- Lyreleaf sage Salvia lyrata · 22 states
- Mapleleaf viburnum Viburnum acerifolium · 27 states
- Marsh marigold Caltha palustris · 28 states
- Mayapple Podophyllum peltatum · 35 states
- Maypop passionflower Passiflora incarnata · 21 states
- Nannyberry Viburnum lentago · 25 states
- Narrowleaf blue-eyed grass Sisyrinchium angustifolium · 21 states
- Narrowleaf evening-primrose Oenothera fruticosa · 10 states
- New Jersey tea Ceanothus americanus · 35 states
- Northern blue flag Iris versicolor · 10 states
- Northern red oak Quercus rubra · 33 states
- Northern spicebush Lindera benzoin · 31 states
- Pagoda dogwood Cornus alternifolia · 30 states
- Partridgeberry Mitchella repens · 31 states
- Pawpaw Asimina triloba · 29 states
- Pin oak Quercus palustris · 27 states
- Pitch pine Pinus rigida · 12 states
- Plains coreopsis Coreopsis tinctoria · 16 states
- Post oak Quercus stellata · 28 states
- Purple clematis Clematis occidentalis var. occidentalis · 15 states
- Purple milkweed Asclepias purpurascens · 20 states
- Quaking aspen Populus tremuloides · 39 states
- Red chokeberry Aronia arbutifolia · 22 states
- Red-osier dogwood Cornus sericea · 36 states
- Royal fern Osmunda regalis var. spectabilis · 30 states
- Sassafras Sassafras albidum · 22 states
- Scarlet beebalm Monarda didyma · 25 states
- Scarlet oak Quercus coccinea · 28 states
- Shagbark hickory Carya ovata · 34 states
- Shingle oak Quercus imbricaria · 18 states
- Smooth Solomon's seal Polygonatum biflorum · 34 states
- Smooth hydrangea Hydrangea arborescens · 23 states
- Smooth sumac Rhus glabra · 42 states
- Southern arrowwood Viburnum dentatum · 28 states
- Southern red oak Quercus falcata · 23 states
- Spotted beebalm Monarda punctata · 29 states
- Stiff dogwood Cornus foemina · 12 states
- Sugar maple Acer saccharum · 34 states
- Sundial lupine Lupinus perennis · 28 states
- Swamp azalea Rhododendron viscosum · 15 states
- Swamp rose Rosa palustris · 27 states
- Swamp white oak Quercus bicolor · 23 states
- Sweet birch Betula lenta · 21 states
- Sweet crabapple Malus coronaria · 20 states
- Sweet-fern Comptonia peregrina · 21 states
- Sweetbay magnolia Magnolia virginiana · 17 states
- Sweetgum Liquidambar styraciflua · 26 states
- Trailing arbutus Epigaea repens · 24 states
- Tulip tree Liriodendron tulipifera · 27 states
- Twoleaf miterwort Mitella diphylla · 25 states
- Umbrella tree magnolia Magnolia tripetala · 17 states
- Virginia bluebells Mertensia virginica · 23 states
- Virginia creeper Parthenocissus quinquefolia · 40 states
- Virginia spiderwort Tradescantia virginiana · 24 states
- Virginia springbeauty Claytonia virginica · 28 states
- Virginia strawberry Fragaria virginiana · 30 states
- Virginia sweetspire Itea virginica · 19 states
- Water oak Quercus nigra · 17 states
- White ash Fraxinus americana · 35 states
- White baneberry Actaea pachypoda · 33 states
- White fringetree Chionanthus virginicus · 21 states
- White oak Quercus alba · 33 states
- Whorled milkweed Asclepias verticillata · 30 states
- Wild blue phlox Phlox divaricata · 36 states
- Wild geranium Geranium maculatum · 33 states
- Willow oak Quercus phellos · 23 states
May in a Delaware native garden
May is Delaware's peak bloom month: 151 of the state's 255 native plants in this directory flower in May, more than in any other month.
36 start blooming in May, including American bittersweet, American cranberry and American strawberry bush. 45 finish in May, including American beech, American hornbeam and Atlantic white cedar, so this is the last chance to see them in flower.
97 of them grow in full or partial sun and 107 tolerate shade, so there are options for open beds and woodland edges alike. Sizes run from low plants like American alumroot and Birdfoot violet to trees such as Allegheny chinquapin and Allegheny serviceberry. For wildlife, 119 support pollinators, 97 provide food or cover for birds and 66 are caterpillar host plants.
126 of the 151 have a seed or plant listing we verified as the wild species. Be careful buying American alumroot, American wisteria, Common yarrow: common listings for these are often a bred variety or a different species.
Good places to start
Verified wild-species listings that take sun and are widely native, so they are forgiving first plants.
- Chokecherry Prunus virginiana · Sun, Part Shade, Shade · blooms Apr-Jul
- Green ash Fraxinus pennsylvanica · Sun, Part Shade, Shade · blooms Apr-Jun
- Smooth sumac Rhus glabra · Sun, Part Shade, Shade · blooms May-Aug