Blue spruce dwarf tree

Picea pungens ‘Montgomery’ / Montgomery Colorado blue spruce

Picea pungens ‘Montgomery’ is considered by many as a classic dwarf conifer and is present in many arboretums and large gardens around the world. This dwarf selection of Colorado spruce is broadly pyramidal, with a somewhat mounding form. Dense, compact branching holds short, fleshy, powder-Blue foliage. After 10 years of growth, a mature specimen will measure 4.5 feet (1.5. m) tall and 3 feet (1 m) wide, and annual growth rate of 4 to 6 inches (10 – 15 cm).

A true Montgomery spruce is usually globose when young and will eventually form a leader, becoming broadly pyramidal with age. A specimen growing in the Harper Collection of Dwarf and Rare Gardens at Hidden Lake Gardens, Tipton, Michigan is now about 35 years of age and is very pyramidal and symmetrical. It is 15 feet (4.5 m) tall with a bottom of 12 feet (3.8 m). The original mother plant is still alive in the New York Botanical Gardens, New York.

This cultivar originated as a seedling selected in the early 1930s at Eastern Nursery, Massachusetts, USA. Later, noted collector, R.H. Montgomery of Greenwich Connecticut obtained the plant, named it after himself, and introduced it to the nursery trade. In spite of the fact that the plant was originally listed under the cultivar name, ‘R.H. Montgomery,’ the shortened name, ‘Montgomery’ has become so prevalent in the international nursery trade, that it’s unlikely ever to be corrected. Apparently several of the dwarf Blue spruce have become mixed in the trade, and ‘Montgomery’ is often confused with the cultivar Picea pungens ‘Globosa’.

Colorado Spruce, Blue Spruce ‘Montgomery’

Category:

Shrubs

Conifers

Water Requirements:

Drought-tolerant; suitable for xeriscaping

Average Water Needs; Water regularly; do not overwater

Sun Exposure:

Full Sun

Sun to Partial Shade

Foliage:

Grown for foliage

Evergreen

Foliage Color:

Blue-Green

Height:

18-24 in. (45-60 cm)

24-36 in. (60-90 cm)

Spacing:

4-6 ft. (1.2-1.8 m)

Hardiness:

USDA Zone 3a: to -39.9 °C (-40 °F)

USDA Zone 3b: to -37.2 °C (-35 °F)

USDA Zone 4a: to -34.4 °C (-30 °F)

USDA Zone 4b: to -31.6 °C (-25 °F)

USDA Zone 5a: to -28.8 °C (-20 °F)

USDA Zone 5b: to -26.1 °C (-15 °F)

USDA Zone 6a: to -23.3 °C (-10 °F)

USDA Zone 6b: to -20.5 °C (-5 °F)

USDA Zone 7a: to -17.7 °C (0 °F)

USDA Zone 7b: to -14.9 °C (5 °F)

USDA Zone 8a: to -12.2 °C (10 °F)

USDA Zone 8b: to -9.4 °C (15 °F)

Where to Grow:

Unknown – Tell us

Danger:

Handling plant may cause skin irritation or allergic reaction

Bloom Color:

Inconspicuous/none

Bloom Characteristics:

Unknown – Tell us

Bloom Size:

Unknown – Tell us

Bloom Time:

N/A

Other details:

Unknown – Tell us

Soil pH requirements:

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

Patent Information:

Unknown – Tell us

Propagation Methods:

By grafting

Seed Collecting:

N/A: plant does not set seed, flowers are sterile, or plants will not come true from seed

Regional

This plant has been said to grow in the following regions:

Tuscaloosa, Alabama

Parker, Colorado

Ashton, Illinois

Bolingbrook, Illinois

Rock Island, Illinois

Bridgewater, Massachusetts

Lexington, Massachusetts

Cleveland, Ohio

Salem, Oregon

Hanover, Pennsylvania

Lexington, Virginia

Warrenton, Virginia

Bainbridge Island, Washington

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Dwarf Blue Spruce: A Superb Year-Round Garden Plant


Dwarf Blue Spruce makes a great focal point in the garden, as a foundation planting, or even as a specimen in a mixed border.

By Ed Moran
Reiman Gardens
Iowa State University Extension

Since its introduction in 1862, the Colorado spruce has become a landscape staple across much of the United States. Its numerous cultivars provide gardeners with almost any desired growth habit, which make it a versatile planting option for year-round interest.

One of the most common cultivars is the dwarf blue spruce (Picea pungens ‘Globosa’). This attractive, slow-growing conifer has many attributes that make it an outstanding addition to any landscape or garden.

Dwarf blue spruce is adaptable to a wide range of growing conditions and is hardy to USDA Hardiness Zone 3 (-40 to -30 degrees F) to 8 (10 to 20 degrees F). It prefers a well-drained to dry soil due to the high elevation of its native habit in the western United States but can easily adjust to most soil types. Its coarse, blue-gray needles are extremely vibrant, especially during spring when new shoots (or candles) break, releasing a flush of soft light blue foliage that remains throughout most of spring and summer. The growth rate of Picea pungens’Globosa’ is quite slow, averaging only 1 to 6 inches per year (3 to 6 feet in 10 years) classifying this conifer as a dwarf.

Maintenance of dwarf blue spruce is minimal. It requires very little attention, except for regular watering during establishment, and selective pruning to control height and habit. Like most plants, dwarf blue spruce benefit from 2 to 3 inches of organic mulch such as shredded bark or composted leaves.

Like most selections and cultivars of Colorado spruce, propagation is accomplished during the winter by grafting new growth of existing plants onto seedling understock of the same species. If grafted onto a taller understock or a standard, the result is a plant with a single-stemmed topiary appearance.

Several other cultivars of dwarf blue spruce are available, including P. pungens ‘Montgomery’ and P. pungens ‘Glauca Globosa.’ These cultivars share similar attributes such as growth habit and color, often causing confusion not only in the landscape but also in the nursery trade.

Dwarf blue spruce is quite versatile in the landscape. It makes a great focal point in the garden, as a foundation planting, or even as a specimen in a mixed border. Additionally, if grown as a standard, a matching pair can create a year-round formal addition to a home’s entryway.

View several dwarf blue spruces in the Dunlap Entry Courtyard and the Walled Courtyard at Iowa State University’s Reiman Gardens.-30-

BlueSpruce.jpg (488K): A color photo, suitable for publication, is available.

Colorado Blue Spruce: A Blue Conifer in All Sizes

(Editor’s Note: This article was originally published on April 10, 2010. Your comments are welcome, but please be aware that authors of previously published articles may not be able to respond to your questions.)

I’m sure all gardeners are familiar with Colorado blue spruce, Picea pungens var. glauca. They are among the # 1 landscape tree for large parks and gardens throughout temperate regions of the world. In December 2008, Geoff Stein (palmbob) wrote a wonderful article on Blue Conifers Choices for the Holidays. This article mentioned a few of the many blue spruce cultivars which exist but as he mentioned, there are far more. This article will go into more depth the wonderful array of blue spruce that you may find in your local nurseries.

As the common name suggests, Colorado spruce is native to Colorado. In fact, they are found wild from Idaho and Wyoming in the north, south through Colorado, Utah, Arizona and New Mexico, growing in mountainous regions. This coniferous tree can reach 40 m (130 feet) in the wild but in cultivation they rarely exceed 25 m (80 feet). The normal species has bluish new growth that fades to green over the winter months. Many gardeners get fooled by this. They purchase a Colorado spruce, thinking it will be blue year-round, only to find it has turned green by spring. No, the plant is not suffering for any nutrient deficiency and adding aluminum sulphate (the chemical that keeps your Hydrangeas blue) will not make it turn back to blue. You simply bought just the regular Colorado spruce, not the BLUE Colorado spruce which is Picea pungens var. glauca. It is important to read the tag! (assuming the plant has one). To ensure you have a REAL blue spruce, you are best to purchase one of the named selections which are generally grafted, therefore true to form.

Above are two examples of the lovely dwarf form called ‘St. Mary’s Broom’

In cultivation, they require full sun and well-drained soil. While they perform admirably under acidic soil conditions, they seem to prefer more neutral to slightly alkaline soil. Colorado spruce are very drought resistant and reasonably tolerant to salt. They are hardy from zones 2 to 8. The blue colour comes from a waxy layer on the needles. In wet climates the wax can be partly lost, dulling out the ‘blue’ effect. In dry climates, the wax remains year-round thus plants in the mid-west are often much “bluer” than the same plant growing in the Pacific Northwest or northeastern North America.

There are nearly 100 named selections of Colorado spruce (not all are ‘blue’ spruce), which can range from under 1 m (3 feet) to towering giants. Most are much too large for the average garden lot so care must be taken to select a smaller form if you do not want to risk the tree outgrowing its allotted space. While there are several green forms and even yellow forms of Colorado spruce, this article will focus just on the “blue” types.

Standard cultivars include ‘Moerheim’, ‘Fat Albert’ and ‘Hoopsii’

Above are two examples of ‘Glauca Pendula’

So what can you choose from if you have a more typical garden lot. There are several semi-dwarf selections that are upright. These often appear more globe-shaped when young but develop a leader with age. They will eventually reach 6 to 10 feet, but they are slow growers. Ones to look for include ‘Glauca Compacta’, ‘R. H. Montgomery’, ‘Jack Corbet’, ‘Thume’ and ‘Hunnewelliana’. The smallest selections will often stay under 1 m (3 feet) thus are suitable for rock gardens and foundation plantings. These include ‘Hillside Dwarf’, ‘Glauca Globosa’, ‘Jean Iseli’ and ‘St. Mary’s Broom’. If you prefer the groundcover effect there are a couple of prostrate, ground-hugging forms namely ‘Glauca Procumbens’ and ‘Glauca Prostrata’. The dwarf globular forms are often top-grafted to produce blue lollipop conifers while the prostrate forms may be top-grafted to produce dwarf weeping forms.

There are no doubt other Colorado blue spruce selections that I have not mentioned. New ones seem to crop up almost yearly. It is worth visiting your local nursery to see what they offer if you are in the market to obtain one of these striking conifers. But please do some research as many of these innocent-looking small conifers can become quite large and will look horrible if you have to continually prune them!

Landscape Plants

  • Conifer, evergreen dwarf tree or shrub, slow growing, 3-5 ft ( m) tall, 5-6 ft ( m) wide in 10 years, mound-shaped, compact, densely branched, blue-green needles.
  • Sun to part shade. Regular watering in dry summer areas.
  • Hardy to USDA Zone 3 It may have been selected in the Netherlands in 1937, or there about, and named ‘Glauca Globosa’. This plant is similar to ‘R.H. Montgomery’ (also called ‘Montgomery’) which was named by the New York Botanic Garden in 1949; there may be some confusion between these two plants in the trade (see below).
  • The following is from the Coenosium Gardens website (2010): “Whether or not a nursery is actually growing ‘Glauca Globosa’ or ‘R.H. Montgomery’ is a moot point since for all intents and purposes there is no difference to the consumer. Propagation of terminals will tend to produce ‘R.H. Montgomery’ while laterals will tend to produce ‘Glanca Globosa’. Enhance the desired effect with careful pruning and the nursery has whichever form it wants (“Poppycock!” says the conifer taxonomist.) The taxonomist is bound “to get bent out of shape” over such a statement, but the nurseryman has to take a more “practical” attitude. There evidently is a ‘Glauca Globosa’ in a collection somewhere, but the nurseryman wants a cultivariant under this name, not necessarily the actual plant. Those of us “in the know” must consider any ‘Glauca Globosa’ as a cultivariant unless the plant can be certified as possessing some characteristic other than growth habit or foliage that distinguishes it from ‘R.H. Montgomery’, and that characteristic has to be traceable back to the oldest labeled ‘Glauca Globosa’ that can be located.”
  • Minnesota Landscape Arboretum, Chaska, Minnesota

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