In recent years discussions have taken place to determine definitions to describe the juvenile habit (or plant shape) of shrubs in order to indicate more precisely the required appearance of the specified shrub. It is important to appreciate that the mature habit of the species can differ from the juvenile shape at time of purchase. The following words are currently used to describe NPS shrubs habit:
A branched shrub is defined as “a plant with lateral shoots arising either from a main stem or from a central point with relatively few sub-lateral shoots.” Examples are Amelanchier spp., Arbutus spp., Forsythia spp., Kerria spp., Sambucus spp., Syringa spp. The majority of shrubs have a branched or bushy habit.
A bushy shrub is defined as “a plant often without a defined main stem. Lateral shoots often arising from a central point but sometimes also from elsewhere. More sub-lateral shoots produced than a branched plant.” Bushy plants normally cover the pot (when container grown) except where a diameter dimension is shown, when it is less than the pot diameter. Examples are Aucuba spp., Buxus spp., Hypericum spp., Lavandula spp., Olearia spp., Skimmia spp.
A shrub with Leader and Laterals is defined as “a plant with a single dominant shoot with significant side shoots.” Examples are Ceanothus spp. (medium and vigorous forms), Ilex spp. (medium and vigorous forms), Parrotia spp., Pyracantha spp.
A shrub with several shoots is defined as “a plant with a number of shoots arising from ground level.” Examples are Cornus spp. (dwarf species), Gaultheria spp., Vaccinium spp. (dwarf species), Vinca spp.
A shrub with a single leader is defined as “a plant with a single dominant shoot with few, if any, side shoots.” An example is Aralia spp.