SCIENTIFIC NAME FLOWERING_PEAK_WEEK Acer palmatum 'Tamukeyama' 29 Apr - 5 May Acer palmatum 'Waterfall' 29 Apr - 5 May Aesculus pavia 13-19 May Aesculus sylvatica 13-19 May Ajuga cv. 29 Apr - 5 May Ajuga reptans var. alba 29 Apr - 5 May Alchemilla vulgaris 29 Apr - 5 May Allium cernuum 27 May - 2 Jun Amsonia tabernaemontana 29 Apr - 5 May Anemone blanda 'Blue Star' 13-19 May Antennaria dioica 6-12 May Aquilegia canadensis 13-19 May Aquilegia canadensis 'Corbett' 13-19 May Arum italicum 'Pictum' 27 May - 2 Jun Aruncus aethusifolius 13-19 May Asimina triloba 29 Apr - 5 May Baptisia australis 13-19 May Betula maximowicziana 20-26 May Calycanthus floridus 'Athens' 13-19 May Cerastium tomentosum 13-19 May Cercis canadensis var. alba 29 Apr - 5 May Chionanthus virginicus 20-26 May Chrysogonum virginianum 13-19 May Clematis 'Nelly Moser' 6-12 May Clematis montana var. rubens 'Odorata' 13-19 May Conradina 'Cumberland Snow' 13-19 May Cornus kousa 13-19 May Cornus sanguinea 13-19 May Cornus x rutgerensis 'Constellation' 13-19 May Cornus x rutgerensis 'Stella Pink' 13-19 May Corylopsis veitchiana 29 Apr - 5 May Cotoneaster adpressus 'Little Gem' 13-19 May Crataegus brachyacantha 6-12 May Crataegus spathulata 6-12 May Deschampsia ceaspitosa 'Gold Shower' 13-19 May Deutzia gracilis 'Nikko' 13-19 May Dianthus plumarius 'Agatha' 20-26 May Dicentra exima 'Adrian Bloom' 20-26 May Dicentra exima 'Luxuriant' 13-19 May Dicentra spectabilis 'Alba' 13-19 May Dictamnus albus 'Purpureus' 27 May - 2 Jun Dodecatheon meadia 'Album' 6-12 May Elaeagnus multiflora 6-12 May Epimedium x youngianum 'Roseum' 13-19 May Euphorbia griffithii 'Fireglow' 6-12 May Exochorda x macrantha 29 Apr - 5 May Fothergilla major 29 Apr - 5 May Galium odoratum 20-26 May Geranium macrorrhizum 'Beven's Variety' 6-12 May Geranium macrorrhizum 'Ingwersen's Variety' 6-12 May Geranium macrorrhizum 'Spessart' 20-26 May Geranium maculatum 20-26 May Geranium maculatum 'Album' 29 Apr - 5 May Geranium sanguineum 'Cedric Morris' 6-12 May Geranium sanguineum 'Shepherd's Warning' 13-19 May Geranium sanguineum var. striatum 13-19 May Geranium sylvaticum 'Album' 13-19 May Geranium wlassowianum 29 Apr - 5 May Geranium x 'Ballerina' 6-12 May Geranium x 'Johnson's Blue' 29 Apr - 5 May Geranium x cantabrigiense 27 May - 2 Jun Geranium x cantabrigiense 'Biokovo' 13-19 May Geranium x oxonianum 'Claridge Druce' 27 May - 2 Jun Halesia diptera 13-19 May Heuchera 'Chocolate Ruffles' 27 May - 2 Jun Heuchera 'Raspberry Regal' 13-19 May Heuchera sanguinea 'Torch' 27 May - 2 Jun Ilex decidua 'Warren's Red' 20-26 May Ilex glabra 27 May - 2 Jun Iris 'White Excelsior' 13-19 May Iris siberica 'Flight of Butterflies' 13-19 May Iris siberica 'Little White' 13-19 May Iris sibirica 'Super Ego' 13-19 May Iris versicolor 13-19 May Iris x germanica 13-19 May Itea virginica 'Beppu' 20-26 May Kalmia latifolia 'Elf' 27 May - 2 Jun Kalmia latifolia 'Olympic Fire' 13-19 May Kalmia latifolia 'Pink Charm' 13-19 May Kalmia latifolia 'Sarah' 13-19 May Kalmia latifolia 'Unknown Cv.' 13-19 May Lamium maculatum 'White Nancy' 6-12 May Magnolia 'Ann' 6-12 May Magnolia acuminata 13-19 May Magnolia acuminata var. cordata 13-19 May Mazus reptans 'Alba' 13-19 May Myosotis 'Victoria Blue' 13-19 May Osmunda cinnamonea 13-19 May Penstemon gracilis 13-19 May Phlox divaricata 'Fuller's White' 29 Apr - 5 May Phlox divaricata 'Laphamii' 13-19 May Phlox maritima 'Rosa Stolz' 27 May - 2 Jun Phlox stolonifera 'Sherwood Purple' 13-19 May Phlox subulata 'Coral Eye' 13-19 May Phlox subulata 'White' 13-19 May Physocarpus opulifolius 'Nanus' 13-19 May Prunus virginiana 6-12 May Ptelea trifoliata 20-26 May Rhododendron 6-12 May Rhododendron 'Blue Peter' 29 Apr - 5 May Rhododendron 'Choice Cream' 29 Apr - 5 May Rhododendron 'Flame Creeper' 20-26 May Rhododendron 'Joseph's Coat' 6-12 May Rhododendron 'Kehr's White Rosebud' 13-19 May Rhododendron 'Lollipop' 27 May - 2 Jun Rhododendron 'Marydel' 13-19 May Rhododendron 'My Mary' 6-12 May Rhododendron 'Scintillation' 20-26 May Rhododendron 'Yaku Queen' 29 Apr - 5 May Rhododendron 'Yellow Delight' 6-12 May Rhododendron alabamense 29 Apr - 5 May Rhododendron alabamense 'Light Yellow' 6-12 May Rhododendron atlanticum 6-12 May Rhododendron austrinum 29 Apr - 5 May Rhododendron austrinum 'Austrinum Gold' 6-12 May Rhododendron canescens 29 Apr - 5 May Rhododendron canescens 'Sp. Found.' 29 Apr - 5 May Rhododendron catawbiense 'Album' 13-19 May Rhododendron flammeum x canescens 20-26 May Rhododendron kiusianum 6-12 May Rhododendron periclymenoides 29 Apr - 5 May Rhododendron periclymenoides 'John Bell Purple Nudiflorum' 29 Apr - 5 May Rhododendron prinophyllum 13-19 May Rhus aromatica 6-12 May Rosa 'Snow Carpet' 27 May - 2 Jun Salvia 'Amethyst' 13-19 May Salvia x superba 'East Friesland' 20-26 May Salvia x superba 'Rose Wine' 20-26 May Stachys byzantina 27 May - 2 Jun Staphylea trifolia 6-12 May Stewartia ovata 29 Apr - 5 May Styrax americana 13-19 May Symphytum asperum 13-19 May Tiarella cordifolia 13-19 May Tradescantia 'Red Cloud' 27 May - 2 Jun Tradescantia x 'Zwanenburg Blue' 13-19 May Veronica 'Waterperry' 13-19 May Viburnum acerifolium 13-19 May Viburnum dilatatum 'Asian Beauty' 13-19 May Viburnum dilatatum 'Erie' 13-19 May Viburnum lantana 'Mohican' 29 Apr - 5 May Viburnum opulus 'Xanthocarpum' 27 May - 2 Jun Viburnum plicatum var. tomentosum 'Mariesii' 20-26 May Viburnum prunifolium 6-12 May Viburnum rufidulum 13-19 May Viburnum setigerum 20-26 May Viola labradorica 13-19 May Viola pedata 13-19 May Wisteria frutescens 'Dark Purple Selection' 27 May - 2 Jun Wisteria frutescens var. nivea 27 May - 2 Jun x Heucherella tiarelloides 'Bridget Bloom' 6-12 May