Quick answer: 45 native Alabama plants have a recorded bloom range that includes May.
45 species
- American beautyberry Callicarpa americana · 10 states
- American beech Fagus grandifolia · 24 states
- American holly Ilex opaca · 24 states
- American wisteria Wisteria frutescens · 14 states
- Black cherry Prunus serotina · 32 states
- Black locust Robinia pseudoacacia · 12 states
- Butterflyweed Asclepias tuberosa · 37 states
- Cardinal flower Lobelia cardinalis · 37 states
- Carolina allspice Calycanthus floridus · 5 states
- Carolina jessamine Gelsemium sempervirens · 9 states
- Common persimmon Diospyros virginiana · 17 states
- Common yarrow Achillea millefolium · 31 states
- Coral honeysuckle Lonicera sempervirens · 16 states
- Coralberry Symphoricarpos orbiculatus · 20 states
- Downy serviceberry Amelanchier arborea · 34 states
- Eastern purple coneflower Echinacea purpurea · 22 states
- Eastern red cedar Juniperus virginiana · 36 states
- Eastern red columbine Aquilegia canadensis · 36 states
- Eastern redbud Cercis canadensis · 30 states
- Flowering dogwood Cornus florida · 22 states
- Foxglove beardtongue Penstemon digitalis · 31 states
- Indian blanket Gaillardia pulchella · 18 states
- Lemon beebalm Monarda citriodora · 15 states
- Maypop passionflower Passiflora incarnata · 13 states
- Mountain witch-alder Fothergilla major · 7 states
- Northern spicebush Lindera benzoin · 16 states
- Pawpaw Asimina triloba · 17 states
- Pink evening primrose Oenothera speciosa · 8 states
- Plains coreopsis Coreopsis tinctoria · 16 states
- Red buckeye Aesculus pavia · 9 states
- Red chokeberry Aronia arbutifolia · 7 states
- Sassafras Sassafras albidum · 22 states
- Smooth hydrangea Hydrangea arborescens · 12 states
- Southern live oak Quercus virginiana · 13 states
- Southern magnolia Magnolia grandiflora · 10 states
- Standing cypress Ipomopsis rubra · 6 states
- Sweetgum Liquidambar styraciflua · 22 states
- Two-wing silverbell Halesia diptera · 5 states
- Virginia creeper Parthenocissus quinquefolia · 27 states
- Virginia sweetspire Itea virginica · 6 states
- White fringetree Chionanthus virginicus · 14 states
- White oak Quercus alba · 33 states
- Wild blue Phlox divaricata · 32 states
- Woodland pinkroot Spigelia marilandica · 4 states
- Yaupon holly Ilex vomitoria · 7 states