a. Spring and early summer-flowering:

Benzoin aestivale

Spice Bush Berberis thunbergi

Thunberg's Japanese Barberry

Cephalanthus occidentalis Button Bush

Cercis canadensis Red-bud

Chionanthus virginica White Fringe

Cornus (in variety) Dogwood

Cotoneaster (in variety) Cotoneaster

Deutzia (in variety) Deutzia

Diervilla hybrida

Hybrid Weigela Dirca palustris

Leather-wood Elaeagnus angustifolia

Russian Olive

Evonymus (in variety) Burning Bush

Forsythia (in variety) Golden Bell

Hamamelis virginiana Witch Hazel

Hippophae rhamnoides Sea Buckthorn

Hydrangea arborescens Wild Hydrangea

Kerria japonica Globe-flower

Ligustrum (in variety) Privet

Lonicera (in variety) Honeysuckle

Philadelphus (in variety) Mock Orange

Physocarpus opulifolius Ninebark

Rhamnus cathartica Common Buckthorn

Rhodotypos kerrioides White Kerria

Robinia hispida Rose Acacia

Sambucus canadensis

American Elder Spiraea arguta

Hybrid Snow Garland

Spiraea billardi Billard's Spirea

Spiraea prunifolia Bridal Wreath

Spiraea tomentosa Hardhack

Spiraea vanhouttei Van Houtte's Bridal Wreath

Stephanandra flexuosa Stephanandra

Syringa (in variety) Lilac

Viburnum (in variety) Viburnum b. Late summer and fall-flowering:

Amorpha fruticosa False Indigo

Buddleia davidi (Cut back in spring to prevent danger of rotting) Sweet-scented Buddleia

Ceanothus americanus New Jersey Tea

Clethra alnifolia Sweet Pepper Bush

Hibiscus syriacus Rose of Sharon

Hydrangea (in variety)

Hydrangea Sorbaria arborea

Chinese Mountain Ash Spirea

Spiraea douglasi Douglas' Spirea

Symphoricarpos racemosus Snowberry

Vitex incisa Cut-leaved Hemp-tree