To make a real container garde, you will need a selection of plants that maintain their good looks without constant grooming, that exude health and vigor and are capable of sustained performance. These are your mainstays. Their job, if they are flowering plnats, is to bloom long and generously. If they foliage plants, their leaves or needles must remain in prostine condition throughout the growing season, and if they are evergreens, beyond.
Which plants will become mainstay in your container garden depends on the kind of garden you have in mind. There are several possibilities:
1. Container garden with annuals and tender perennials which bloom during summer and fall months
Annuals and tender perennials will give you an opportunity to try out new color schemes, experiment with unfamiliar plants, and make your surroundings look different every year.
2. Container garden that gives you something to look at all year
This is the type of garden to use if you do not favor change for its own sake and you don't have to start from scratch every season. Trees and shrubs stay, but you can still experiment with different annuals and rearrange smaller plants every summer.
3. Evergreen container garden
If you do not want your garden to be bare for 6 months of the year, you need evergreen shrubs and trees, which also serve as a background for summer flowers.
No matter what type of garden you choose, you will need a palette of basic plants. For four-season container gardens these plants include dwarf conifers and broadleaf evergreens, small deciduous trees, ornamental grasses and other hardy perennials, annuals and tender perennials.
Dwarf Alberta Spruce 'Elf'
Picea glauca 'Elf'
Photo credit: Conifer Gardens Nursery
Dwarf Conifers and Broadleaf Evergreens
Slow growing by nature, the following and other dwarf spruces are undemanding. Hardy to zone 4, dwarf spruces come in many forms and different tones of blue and green:
- P. pungens "Fat Albert's" has a perfect conical shape and blue needles
- P. glauca "Little Globe" forms a neat ball and has short, dense light green needles
- P. pungens "Iseli Fastigate" with blue needles grows into a very narrow and upright column reaching a height of about 12 feet in 10 to 15 years. It is an excellent accent plant.
Sun-loving junipers are cold tolerant to zone 3 and come in different colors and forms:
Juniperus communis "Pencil Point"
Juniperus communis "Pencil Point" has silver-blue needles and grows to a slender 6 feet, has a bright yellow cousin, Juniperus communis "Gold Cone", also narrow and upright. Both are attention getters and can be used as exclamation marks in a container garden. Grow in very poor soils, very adaptable to different soil types. Juniperus chinensis 'Pyramidalis' is a neat shrub with a smooth pyramidal outline. The foliage is a bright steel-blue color. Grows to approx 5 feet in 10 years.
While upright junipers are useful as screening as well as accents, trailing forms bring the container garden down to earth. For this purpose, try one of the following:
Juniperus horizontalis "Wiltonii"
Juniperus horizontalis "Wiltonii", also called "Blue Rug Juniper", and "Wilton Carpet Juniper." One of the slower growing and most prostrate Blue Junipers. One of the best flat forms.
Juniperus procumbens "Nana"
Also called "Dwarf Japgarden juniper", this variety has short, crowded sea green needles. It has wide spreading form; lays flat on ground if given adequate space or mounds up in center if crowded. Hardiness zone 4-9. Tolerant of many soils, thrives under adverse conditions.
Dwarf Thuja 'Teddy'
Thuja occidentalis 'Teddy''
Photo credit: Conifer Gardens Nursery
These tough, tolerant evergreens are hardy from zones 3 to 7 and have proved to be excellent trees for different situations. Cultivars of arborvitae come in green and gold and assume many shapes, from narrow pyramids, like round balls, like "Little Gem" (1-3 feet high and 4-6 feet wide) and "Little Giant." Dwarf Thuja "Teddy" (Thuja occidentalis 'Teddy' ) is an extremely compact shrub, forming a tight round ball. The soft green foliage turns a plum-color in winter. In 10 years a height of 1.5 feet may be reached. Thuja occidentalis 'Globosa' is a globular shrub with dark green foliage that turns copper in autumn. The sprays of foliage are arranged in a haphazard manner. Grows to approx 5 feet high. Thuja occidentalis 'Sunkist' is a conical shrub with golden foliage that turns old-gold in winter. Grows to approx 5 feet in 10 years. Thuja orientalis 'Aurea Nana' ("Golden Biota or Bookleaf") is a very popular conifer, forming a neat globular shape with a smooth outline. In summer the plant is bright gold, greener in winter. Very hardy, excellent in pots.
- Pinus mugo Mugo pine is a sun-loving pine which can survive wind and heat and is easily adaptable.
- Pinus aristata Bristlecone pine, a tree with irregular form and dark needles. It grows well from zone 4 to 7.
- Pinus aristata Bristlecone pine, a tree with irregular form and dark needles
Dwarf Rhododendrons and Azaleas
The genus Rhododendron, which includes azaleas, is enormous, with as many as 800 species. Hybrids derived from Rhododendron yakishimanum, a dwarf species from the Japanese island of Yakishima, are particularly well suited to container gardens. The so-called Yaku hybrids remain small in stature and have superb foliage—dark green and glossy above, lined with soft, fawn-colored feltlike hairs underneath. The flowers come in white and different shades of pink.
Evergreen azaleas, ranging in height from 18 inches to 3 feet, also make good container plants. Low growing, densly twiggy, and well furnished with small, shiny leaves, they offer year-round good looks and lively pink, red, or white flowers early in the season: "Gumpo Pink" has a low, domelike profile; "Hino-Crimson" is an old favorite with a mounding habit; "sir Rober" becomes a compact three-by-three-foot plant bearing large pink flowers.
Of particular interest to container gardeners are the following miniatures:
"Little Linda", with shiny, dark green leaves on a bushy two-foot plant with a spread of about 3 feet. The flowers are deep pink in bud and
open to a paler pink;
"Minuet", similar to "Little Linda", cinnamon red cup-shaped flowers;
Other miniatures include "Elf," with white flowers, pink-flowered "Tinkerbell," and "Tiddlywinks."