While trees are always a spectacular addition to your garden, the fact is many people don’t have room for many of them. Trees can take up a lot of space, and especially in an urban garden it’s easy for them to become overwhelming rather than impressive. There’s a solution though – dwarf trees. Many of the most popular trees, especially evergreens, are available in compact dwarf varieties that give you the appearance of their bigger brothers without needing anywhere near as much space. One very popular, and highly recommended, example is the dwarf Colorado spruce variety Glauca Globosia.
Colorado spruce, Picea pungens, is an attractive blue-green conifer native to the Rocky Mountains from Canada to Wyoming. In the wild it’s a large tree that often reaches 75 feet or more in height, and in gardens it’s not uncommon for it to reach 50 feet and a width of 16 feet or more. That obviously makes it a tree for people who have a lot of space, but the neat little Glauca cultivar brings the looks of the Colorado spruce within reach of any gardener. It’s small enough that it will fit in any space, either as a centerpiece in a modest garden or an accent plant in a larger one.
The full sized Colorado spruce has a classic conical evergreen shape, but its miniature cousin forms a compact globe. When mature it’s usually between three and five feet high, and spreads from four to six feet wide. It still retains all the other aspects of the wild tree’s appearance though. Its branches are thickly covered with stiff four-sided needles, whose blue-green to silver-blue color gives the species its other name of blue spruce. This species doesn’t flower but it does produce cones. However its main attraction is the foliage, whose color doesn’t fade throughout the year and will create an interesting scene even in winter.
Glauca Globosa is quite a hardy plant, with a few limitations. It will grow well in USDA plant hardiness zones 2 to 7. That means it can be grown right to the northern borders of the USA and will survive a Midwestern or New England winter with ease; its Rocky Mountain heritage has made it very tough in cold weather. It’s not so suited for warmer climates though, and won’t do so well in strong sunlight or high humidity. If you’re in the Deep South this is a shrub you may want to pass by. Otherwise, however, it’s quite easy to look after and very versatile. The main thing to watch is that you don’t let the soil around it dry out too much while it’s young. As it matures it becomes more tolerant of the occasional short dry spell.
The dwarf blue spruce prefers moist, organically rich soil but isn’t too fussy about pH levels. As long as the ground is well drained but with good water content your Glauca should thrive in it. It’s happiest in full sunlight rather than shade, but if you have very intense summer sun an area that gives dappled shade in the afternoon may be better; it’s best not to let it get overheated. This shrub doesn’t suffer from any serious insect or disease problems. It may attract aphids, scale, bagworms and budworms, so check it periodically and treat if required, but it’s not particularly vulnerable to any of them. In terms of disease it can be affected by needle cast or rust; watch for needles turning brown then falling off. Overall, however, it’s generally a robust little tree.
Not much pruning is required with this species, beyond removing any dead branches to encourage new growth. If you want to shape it, however, it can be pruned into a good range of shapes. Its height makes it an ideal choice for an attractive hedge – going for this option will add real character to your garden’s boundaries thanks to its distinctive color and dense foliage. There are many other ways to get the most from it, though. It looks great as the centerpiece of a flower bed, or in a rock garden. A clump of them will provide an attractive habitat for small animals like chipmunks. Thanks to its size it’s also a good choice for a large container, so you can liven up a patio or deck.
Dwarf trees don’t have the presence of a full sized version but they do have many advantages of their own, especially in an urban garden. They require less maintenance and don’t become excessively dominant – a normal Colorado spruce can take over a typical suburban garden and crowd out anything nearby. Glauca Globosa won’t do that; it stays a much more manageable size, making it a very versatile shrub whose uses are limited only by your imagination. Between its distinctive appearance and year-round vitality it’s a great addition to any garden with the right climate, and at The Tree Center we have no hesitation in recommending it.