The needles are a rich green or green-gray and quite fragrant. The tree is typically planted in late fall. Patient gardeners with enough land to properly host a cedar of Lebanon tree can expect a pyramid-shaped tree for the first 20 or so years that eventually flattens as it ages. Beyond that, caring for a cedar of Lebanon tree is rather straight-forward. It prefers well-drained soil and full sun in order to thrive. As the tree is getting established, you’ll want to be mindful of extreme weather conditions that can damage its still-developing young branches. Make sure to plant the tree away from your home or other large structures that can be damaged by a falling tree should your cedar of Lebanon rot or come down unexpectedly.
Light
Plant your cedar of Lebanon tree in a spot with at least eight to 10 hours of sunlight daily. This shouldn’t be too hard to achieve—chances are, the tree will be the tallest thing in your landscape (at least, after a few years’ time), so it’s unlikely that it will be shaded by other trees and kept out of the sun.
Soil
Cedar of Lebanon trees prefer acidic soil, but can also be grown in soil with neutral and alkaline pH levels. When it comes to the composition of their soil, they will do best if planted in moist but well-drained soil. Any soil that is too mucky or poor draining will result in root rot and ultimate failure.
Water
Water your cedar of Lebanon plant deeply at least once a week, and make sure the soil doesn’t dry out, especially in its first few years of life.
Temperature and Humidity
The cedar of Lebanon tree is a very adaptable varietal and can handle a range of temperatures both cold and warm. It can thrive in the high heat of summer (similar to the conditions in its native land), and withstand very low temperatures in winter.
Fertilizer
Fertilize your cedar of Lebanon tree from the end of winter to the end of spring, using a complete all-purpose fertilizer that is slow-release. You do not need to fertilize the plant from the spring on. During the tree’s first two years of life, it’s wise to choose a fertilizer mixture that also includes phosphorous to encourage strong roots.
Types of Lebanese Cedar
There are two dwarf varieties of Lebanese cedar, both used for bonsai growing:
C. libani ‘Green Prince’ (sometimes erroneously referred to as ‘Green Knight’). After ten years, this extremely slowly growing variety (2 to 3 inches per year) reaches only 3 feet in height.C. libani ‘Katere’ is a cultivar with a maximum height of 6 feet. It was bred in New Zealand.
Pruning
The cedar of Lebanon tree can be pruned to form a central leader if desired, as it may form several different ones if left alone. However, the multiple leaders help the tree form into an attractive shape. Any pruning should be done during the fall and only be done to trees that have matured beyond their first few years of life. Altogether, pruning is not necessary unless done for aesthetic or safety purposes.
Propagating Lebanese Cedar
Cuttings of Lebanese cedar are virtually impossible to root. The only method of propagation is from seed.
How to Grow Lebanese Cedar From Seed
To grow the tree from seed takes patience but it can be done.
Start by collecting several cones from an established tree. Place the cones in a paper bag and store them in a cool, dry place until the cones “ripen,” indicated by the scales cracking open and spilling their seeds. Soak the seeds in a bucket of water for three hours or more. Discard any seeds that float (they’re not viable) and collect any that sink. To activate germination, wrap the viable seeds in a moistened cheesecloth or paper towel and place them in a plastic bag. Store in the refrigerator for one month, making sure to mist the cloth whenever it feels dry to the touch. When the time comes to plant your tree, prepare pots (as many as you have seeds) that are at least 3 inches deep and filled with a mixture of potting mix. Coat the seeds with powdered fungicide then place each one in its individual pot, topping them with more sand and peat mixture. Water until the mixture settles and water runs from the drainage holes in the base of the pot. Place the pots somewhere that will get at least six hours of sunlight a day and watch for germination. Once you notice the seeds have germinated, transplant the seedlings into larger gallon-sized containers to grow through the winter. The saplings can then be planted in the landscape in the spring after the last frost has passed.
Potting and Repotting
Due to its size, Lebanese cedar is not suitable to be grown in pots but a dwarf variety can be trained as a bonsai.
Overwintering
The tree is hardy to USDA zone 5 and needs no winter protection. The roots of a potted bonsai, however, might need to be insulated against winter cold by wrapping the container in burlap and bubble wrap, or placed in an insulating silo for overwintering.
Common Pests & Plant Diseases
There are not too many problems associated with cedar of Lebanon trees. You may see some aphids on the tree, which can be naturally managed by ladybugs or removed simply by spraying them off the branch with water. Root rot is another issue but can be rectified by maintaining well-draining soil.