Berks County Cooperative Extension -

ORNAMENTALS FOR SMALL SPACES

Shrubs and trees on standards.

With lot sizes on the decrease in many areas, there has been increased interest in trees and shrubs that will fit well in limited spaces. The recent trend in offering ornamental plants for small spaces has taken on a new twist with niche-seeking nurseries and garden centers offering popular shrubs and trees on standards. ( A standard is a plant that that is trained to a single stem in tree form.) In both the United States and Canada, nurseries are grafting popular shrubs onto 31-70" standard rootstocks and stems. (Grafting is a method of propagation by which an artificial union is made between two plant parts from different varieties.)

Plants marketed on standards.

Among others, the following plants are being marketed on standards:

Botanical name	Common name
Cotoneaster praecox	Early cotoneaster
Eunonymus fortunei 'Emerald Gaitey'	Emerald gaitey eunonymus
E. fortunei 'Canadale Gold'	Canadale Gold eunonymous
Forsythia ovata 'Northern Gold'	Northern Gold forsythia
Hibiscus syriacus 'Arden' and 'Lucy'	Rose of Sharon varieties
Hydrangea paniculata 'Grandiflora'	Peegee hydrangea
Syrina chinensis 'Saugeana'	Chinese lilac
Syringa meyeri 'Palibin'	Dwarf Korean lilac
Viburnum x Carlcephalum	Fragrant Snowball Viburnum
Viburnum opulus and V. opulus 'Roseum'	European Highbush Cranberry and European Snowball Viburnums
Weigela florida 'Nana Vareigata' 'Red Prince'	Variegated and Red Prince Weigela

Issues to consider.

While grafting popular shrubs onto standard rootstock and stems may be an effective means of expanding the availability of attractive, flowering and distinctive shrubs and trees for the patio garden, home gardeners should be aware of potential drawbacks. Each plant has a distinctive growth habit, hardiness and pruning requirements. For example, Weigela as a shrub may die back to the ground under extreme weather conditions. On a standard, this plant may require winter protection in a fashion similar to tree roses. Similarly, 'Northern Gold' forsythia, an upright shrub, can grow to six to eight feet in height. Grafted to a standard, this forsythia may become difficult to manage and prune.

Losing the top.

The potential for loss of the cultivar on top of the standard should be of concern to home gardeners. Conditions that may lead to the top snapping off include:

Maintenance and environment in which the plant is grown. The tops of poorly maintained plants may give way under gusty winds or heavy accumulations of ice and snow.
Incompatibility between the scion (portion of the cultivar to be propagated) and the rootstock. Graft incompatibility may result in plants growing for years with the graft union between the two species weakening over time. The eventual result may be the top breaking out of the specimen. Purchasers should ask the vendor about the understock species or genus and whether there is the potential for incompatibility problems. Inquiry should also be made as to a warranty or replacement policy in the event of graft incompatibility.

Penn State Home Gardener Headlines (Berks County) (Summer 1999)
Document created: 15 December 1999; Revised: 3 March 2001