Conifers Contained

Posted in Gardening Tips on January 11 2011, by Sonia Uyterhoeven

Sonia Uyterhoeven is Gardener for Public Education.

Last week we were looking at some dwarf conifers that would be suitable for the perennial garden. Remember that miniature conifers grow less than one inch a year; dwarf conifers grow 1-6 inches per year; and the epithet ‘nana’ that you often see in cultivar names means ‘dwarf’.

This week we will look at miniature and dwarf conifers as excellent candidates for container gardens. When choosing your conifers for a container garden make sure that you not only pay attention to the growth rate (a miniature or dwarf conifer will be your best choice), but also to its growth habit. Some conifers spread and are not suitable for containers (use them as ground covers). Look for mounding, rounded or upright forms.

Dwarf conifers thrive in containers and are comfortable with restricted root growth. Nonetheless, it is best to choose a container that is at least 4-6 inches wider than the container that your conifer came in so that you give it space to grow.

Container grown conifers need good drainage. This is generally provided by standard potting mixes. These mixes, however, tend to be light and evergreens are prone to blowing over in heavy winds. The remedy is simple: weight the bottom of the container down with gravel or small stones. You not only provide a layer of drainage but also add stability with the additional weight.

Feed your conifer in the spring with a slow-release fertilizer. Remember not to over-fertilize – you are not trying to push growth. Water your container regularly so that the conifer does not dry out. For city dwellers that battle with exposed sites, pines and junipers fare well. Below is a list of some suitable container conifers.

Chamaecyparis obtusa ‘Golden Sprite’ — Dwarf Golden Hinoki-cypress
Chamaecyparis obtusa ‘Mariesii’ — Variegated Hinoki-cypress
Chamaecyparis obtusa ‘Nana Gracilis’ — Dwarf Hinoki-cypress
Chamaecyparis obtusa ‘Tsatsumi Gold’ — Golden Hinoki-cypress
Chamaecyparis pisifera ‘Filifera Aurea Nana’ — Dwarf Threadleaf Sawara-cypress
Chamaecyparis pisifera ‘Tama-himuro’ — Miniature Sawara-cypress
Picea pungens ‘R.H. Montgomery’ — Dwarf Blue Colorado Spruce
Pinus mugo ‘Honeycomb’ — Dwarf Mountain Pine
Pinus mugo ‘Paul’s Dwarf’ — Dwarf Mountain Pine
Pinus mugo ‘Pot o’ Gold’ — Dwarf Mountain Pine
Pinus strobus ‘Coney Island’ — Dwarf Eastern White Pine
Pinus strobus ‘Sea Urchin’ — Miniature Eastern White Pine
Thuja occidentalis ‘Hetz Midget’ — Dwarf American Arborvitae
Thuja occidentalis ‘Teddy’ — Miniature American Arborvitae
Tsuga canadensis ‘Jervis’— Dwarf Eastern Hemlock

Come visit both our perennial garden and the Benenson Ornamental Conifer Collection to see a fine collection of miniature and dwarf conifers. In our ornamental conifer collection we have an area devoted to conifers for the sun and correspondingly one for shadier situations.