Botanically speaking, mugo pine is a tree, but it is very successful when grown as a shrub. Its extreme hardiness exceeds that of even juniper, so it is among the few evergreens that will grow for gardeners in the coldest of climates. And, because of mugo pine’s ability to withstand strong sun, it is equally at home in hot, arid landscapes, or anywhere in between.
The stocky, upright branches are covered in 2.5-centimetre-long to five-centimetre-long (one-inch-long to two-inch-long) green needles and feature upright new stem tips, called candles, in late spring. This is a pine that rarely manages to grow more than 1.5 metres (five feet) above the ground, but its width can equal its height.
Location, location, location
- Mugo pine is often used as a specimen plant in places that are difficult to irrigate, such as near streets, at driveway entrances, or along the outer edges of a large lawn.
- But its compact size also makes it a good choice for rock gardens, small beds, and foundation plantings.
- It’s a good neighbour to medium-sized, sun-loving perennials and creates a pleasing combination of textures when planted along with ornamental grasses.
There are even cultivars, such as the 30-centimetre-tall (one-foot-tall) and 45-centimetre-wide (18-inch-wide) ‘Slowmound’, that are small enough to be used in containers or troughs.
For many years mugo pines were propagated from seed, which led to variation in the size and growth habit of plants available at nurseries.
Inexpensive mugos are still grown from seed, so even plants of respected varieties, such as ‘Compacta’, may look a little different from one another as they mature.
Happily, nurseries have recently begun propagating mugos from cuttings, making it possible to create more uniform plants. As part of this development, new named cultivars are beginning to appear for sale, including the one-metre-tall (three-foot-tall) ‘White Bud’, which sports nearly white branch tips, or candles, and the bushy ‘Big Tuna’, which grows 1.5 metres (five feet) tall and equally wide.
Also look for dwarfs, such as ‘Winter Gold’ and ‘Ophir’, whose foliage turns from deep green to golden yellow during the winter.
Growing mugo pine
- Set out container-grown plants in spring in cold climates or anytime except midwinter.
- Dig a hole as deep as the nursery container and twice as wide.
- Although the plants can adapt to any type of soil, get the roots off to a good start by amending the soil with organic matter.
- Fill the hole and top it off with a five-centimetre-thick (two-inch-thick) layer of organic mulch to retain soil moisture and suppress weeds.
- Expect to see only modest growth the first year after planting, followed by faster development in succeeding seasons.
- Mugo pines do not need pruning, but should they threaten to grow too tall for their site, the upward growth can be stopped by breaking off the candles in early spring. This is seldom necessary with newer cultivars.
- Unlike many other pines, mugos shed very few needles. It is their habit to hold needles for up to five years.
- Don’t worry if up to one-fourth of the needles drop in late fall; they will quickly be replaced by a new crop.
- A pest called pine sawfly occasionally feeds on the new growing tips in mid- to late-spring.
- Control these small caterpillars with red heads by applying insecticidal soap according to directions.
- Treat promptly, because an uncontrolled infestation often results in a more damaging population the following year.
Plant and enjoy these evergreens for years to come.