PRUNING REQUIREMENTS 297 



Sambucus canadensis Spiraea tomentosa 



American Elder Hardhack 



Spiraea arguta Spiraea vanhouttei 



Hybrid Snow Garland Van Houtte's Bridal Wreath 



Spiraea billardi Stephanandra flexuosa 



Billard's Spirea Stephanandra 



Spiraea prunifolia Syringa (in variety) 



Bridal Wreath Lilac 



Viburnum (in variety) 

 Viburnum 



b. Late summer and fall-flowering: 



Amorpha fruticosa Hydrangea (in variety) 



False Indigo Hydrangea 



Buddleia davidi (Cut back in spring to Sorbaria arborea 



prevent danger of rotting) Chinese Mountain Ash Spirea 



Sweet-scented Buddleia Spiraea douglasi 



Ceanothus americanus Douglas' Spirea 



New Jersey Tea Symphoricarpos racemosus 



Clethra alnifolia Snowberry 



Sweet Pepper Bush Vitex incisa 



Hibiscus syriacus . Cut-leaved Hemp-tree 



Rose of Sharon 



B. SHRUBS NEEDING REMOVAL OF OLD WOOD ONLY: 



a. Summer pruning: 



Caragana Magnolia 



Pea Shrub Magnolia 



Daphne Mahonia 



Deciduous Daphne Oregon Grape 



Halesia Prunus cerasus 



Silver Bell Flowering Cherry 



Koelreuteria Pyracantha 



Varnish Tree Evergreen Thorn 



Laburnum vulgare Rhododendron 



Golden Chain Rhododendron 



Lonicera tatarica Staphylea 



Tartarian Honeysuckle Bladder-nut 



Xanthoceras 

 Chinese Flowering Chestnut 



b. Winter pruning: 



Aralia Pavia 



Angelica Tree Dwarf Horse-chestnut 



Artemisia Robinia Pseudacacia 



Wormwood Black Locust 



Cladrastis Yucca 



Yellow- wood Adam's Needle 



