PLANT OF THE MONTH
March, 2007
Plant of the Month Feature
by Alan Craig
Arboretum Board Member
Picea pungens
'Mongtomery'
Montgomery Globe
Colorado Spruce
'Dwarf' is a relative word. I was reminded of this as I walked through the Heartland Collection of Garden Conifers at the Bickelhaupt Arboretum with Dave Horst, the Bickelhaupt's grounds supervisor, in December of 2006. One of the most impressive dwarf conifers in the Heartland Collection is a large specimen of Picea pungens 'Montgomery' (a dwarf, globose form of Colorado Spruce) that is 30 to 35 years old.
This particular plant measures approximately 12 feet high by 12 feet wide. And what a dramatic specimen it is! But you may be saying to yourself, "I thought that 'dwarf' meant small." Well, it does, but as I mentioned, 'dwarf' is relative. A 30 year old Colorado Blue Spruce of typically tree sized proportions would be anywhere from 30 to 40 feet tall, by 15 to 20 feet wide. So even at 12 feet, this 'Montgomery' is quite small in relation. One must remember that even though a dwarf plant might grow only about three or four inches per year, as 'Montgomery' does, these few inches, over many years, add up to feet!
Don't let 'Montgomery's eventual size prohibit you from using it in your garden though, for that would be a shame, because 'Montgomery' Colorado Spruce is such a beautiful and useful plant. 'Montgomery' has a very dense, rounded to pyramidal form. Especially on sunny days, its bright silver blue needles fairly glow, adding welcome color to the drab winter landscape or a splash of contrast to all the shades of summer green. It makes excellent habitat for birds with its protective needles and dense habit making it nearly impenetrable to cats, raccoons, and other animals that prey on birds. For these same reasons, it also makes an excellent informal hedge. 'Montgomery' is also nearly indestructible to the rigors of mid-western weather, and has few serious disease or insect pests. Deer usually leave it alone as well. I would also like to add, as a note from personal experience, that 'Montgomery' will withstand quite a snow load. I have one planted beside a driveway, and snow sometimes will completely cover it, but I have never seen a broken branch on it from too much snow.
As for culture, 'Montgomery' spruce should be planted in full sun and in well-drained soil. Once established, it is very drought resistant. Commonly this plant is rounded in form, but frequently a leader develops, and this leads to a pyramidal form. If you prefer a more rounded form, just clip out the leader. This will also help to limit the ultimate height. Size can be limited by trimming lightly in the late summer or very early spring before growth starts. Otherwise, approximate size for a 20 year old plant is six to eight feet high and wide. And remember, with age it will continue to grow and add bulk, but very slowly. Just keep this in mind when you plant it and allow it a little room to grow, or if room is too limited, when it gets too large just remove it and plant a new one. 'Montgomery' is just too beautiful and useful to not have at least one in your garden.
About the Author: Alan Craig grew up on a ranch in Colorado and earned a Bachelor of Science degree from the University of Northern Colorado. Upon graduation, he worked for nursery and landscape firms in Colorado for six years. He has been with Iseli Nursery, Inc. in Boring, Oregon, in sales and product development for 20 years. His other horticultural related interests include plant geography, landscape gardening, and forest management. The Bickelhaupt Arboretum is fortunate to have Mr. Craig on its Board of Directors.