Fir trees, including the Korean fir (Abies koreana), are a popular choice for live Christmas trees. But beyond that, the Korean fir is ideal for landscape use, especially if you don't have the space for a larger fir species. This evergreen tree is known for its fairly slow growth rate, gaining only around 1 to 6 feet per year and reaching its mature size in roughly 10 years. It is best planted in the fall. Korean firs grow in a cone or pyramid shape with dense branches and short needles that are dark green on top with silvery undersides. They produce distinctive cones that are around 3 inches long, which start out purple and mature to a tan color.
|Botanical Name||Abies koreana|
|Common Names||Korean fir, kusang namu|
|Mature Size||15–30 ft. tall, 6–12 ft. wide|
|Sun Exposure||Full, partial|
|Soil Type||Rich, moist, well-drained|
|Hardiness Zones||5–7 (USDA)|
Korean Fir Care
Korean firs are generally very low-maintenance trees, especially after they are established in the landscape. The key is to start them off right, planting them in a spot that has good drainage and preferably rich, acidic soil. Also, make sure to take into account their mature size when determining their spacing in the landscape. Having to transplant them can damage the roots and weaken or kill the tree.
Plan to keep new trees well watered, especially in the summer, and feed them annually. You likely won't have to do much, if any, pruning on your tree unless there's an unhealthy portion you need to take off. Just inspect it periodically for any signs of distress.
This tree grows well in full sun, meaning at least six hours of direct sunlight on most days. But it also will tolerate partial shade.
Korean fir trees prefer a rich soil with good drainage. They also like an acidic soil pH. They can tolerate a neutral pH but won’t grow well in alkaline soil. They also don’t do well in clay soil.
These trees prefer consistent moisture in the soil, but they struggle in soil that remains too wet and soggy. So water your tree whenever the soil begins to dry out, but make sure no water is pooling around the tree. A layer of mulch around the tree can be helpful to retain adequate soil moisture and keep the roots cool.
Temperature and Humidity
Korean firs tolerate heat and humidity better than many other fir trees. But they still prefer a cool, temperate climate. They also can handle some wind but should be sheltered from strong winds that can be extremely drying.
Feed young Korean fir trees annually in the early spring before new growth picks up with an organic granular fertilizer. Mature trees can be fed at half strength unless you have poor soil.
Korean Fir Varieties
There are several varieties of Korean fir trees, including:
- Abies koreana 'Aurea': This variety is commonly known as the golden Korean fir, thanks to its bright golden needles in the spring that turn light green by winter.
- Abies koreana 'Compact Dwarf': This especially small variety only reaches around 5 feet tall and 3 feet wide.
- Abies koreana 'Silberlocke': The needles on this tree curl upward to expose more of their silver-white undersides.
- Abies koreana 'Kohout Hexe': This miniature variety grows only around a foot tall.
- Abies koreana 'Silver Show': This variety features very tightly curled needles that expose their silver undersides.
Korean fir trees don’t require much in the way of pruning. They typically form a symmetrical pyramid shape all on their own. However, you should prune off any dead, diseased, or broken branches as you spot them. And you can prune any unsightly branches as needed. But don’t cut back branches extensively and expect them to regrow. You’ll likely end up with some bare branch stubs where you cut.
These trees don’t have serious issues with pests or diseases, though they don't do well in areas with high air pollution. They can be susceptible to certain insects, including aphids and adelgids. If these insects are present, the tree’s needles might turn yellow or drop off. Forcefully spraying the needles with water to dislodge the insects every other day or so is a natural way to get rid of them. You also can apply an insecticidal soap or horticultural oil, though this can discolor foliage. It’s important to remove and replace any mulch around your tree each spring to prevent any dormant insect pests from returning and infesting the tree.