Mugo pine, dwarf Alberta spruce, pinyon pine, bristlecone pine, arborvitae and American holly all stay small enough for a narrow bed or a side yard. Rocky Mountain juniper cultivars belong on that list too. The small evergreen trees that work in a tight spot share one habit, since they reach a set size and then hold it instead of pushing past your roofline. Penn State Extension puts mugo pine at 8 feet (2.4 m) at the top end, and most plants come in under that.
"Is that little pine going to eat your walkway?" my neighbor asked, nodding at the mugo pine by my front step. I planted it there three springs back. It was knee high then and already as wide as it was tall. A mugo carries an equal spread, so a plant that reaches its full 8 feet (2.4 m) of height also covers 8 feet (2.4 m) of ground, and your bed has to be that wide long before the plant gets there.
Mature spread is the number people skip, and in a narrow bed it matters more than height does. A plant with an equal spread claims as much ground as it does air, so you owe it a circle of open soil as wide as the tree is tall. Look up as well. Power lines, a low roof edge and a bedroom window all cap what you can plant under, and no pruning fixes a tree that wanted twice the size of its slot. Good evergreens for small yards fit both numbers without a fight.
Mugo Pine
- Mature height: Reaches up to 8 feet (2.4 m) and often stops well short of that.
- Spread: Equal to its height, so give the bed as much width as the plant will gain in height.
- Cold tolerance: Hardy to Zone 4, which covers most cold northern yards.
American Holly
- Mature height: 15 to 20 feet (4.6 to 6 m) once it settles in.
- Mature width: 6 to 10 feet (1.8 to 3 m), so it stays much taller than it is wide.
- Cold tolerance: Zone 6, so it wants a milder winter than the mugo pine.
Rocky Mountain Juniper Cultivars
- Named picks: Grey Gleam, Sutherland and Wichita Blue sit in the small tier.
- Second job: Junipers make excellent windbreaks, which helps on the exposed side of a house.
- Home ground: Native evergreens outperform trees brought in from other areas on similar sites.
Plenty of dwarf conifers sit in that same small tier, so you have more to pick from than the tags by the door suggest. Pinyon and bristlecone pines make the same list, and so do dwarf Alberta spruce and arborvitae. The juniper cultivars round it out. Ask your nursery for the mature height and spread of the exact cultivar, not the species. A dwarf form and its full-size parent often share one common name.
Measure before you shop. Run a tape from the wall to the walk and write your number down, because a tree set in the middle of a strip 4 feet (1.2 m) wide has only 2 feet (0.6 m) of room on each side. Most small evergreen trees fail in a spot like that for one reason, and the reason is width. Match that full width against the mature spread on the tag before you pay for anything.
Start with the space and let it pick your plant. Measure the width, hold that number against mature spread, and lean toward a native tree if you have the choice. Colorado State University Extension reports that native evergreens outperform trees brought in from other areas, and the gap is widest on ground like the ground they grow in on their own. Mugo pine handles Zone 4 and American holly wants Zone 6 or milder, so your tight bed has a different answer in each yard.
Read the full article: Evergreen Trees: 8 Types and How to Choose
