Dwarf mugo pines grow to be about 3 to 5 feet tall at most, but the spread of these plants can be much larger. At times, a dwarf mugo pine may reach a width of 10 feet. However, it will take a long time for this pine to reach that size because it is a very slow-growing plant. Non-dwarf varieties of this plant will be much larger, becoming 20 feet tall or more in some scenarios.