How to Grow and Care for Mastic Trees

The mastic tree is a broadleaf evergreen known for its shrublike appearance, sticky sap, and drought tolerance. The mastic tree grows best in high heat in arid, rocky climates with low humidity. The tree needs full sun and dry, alkaline, and well-draining soil.

Mastic Tree Care

Here are the main care requirements for growing a mastic tree.

• Plant the tree in full sunlight.
• Use dry, sandy, gritty soil that will not retain water.
• Water a young, newly planted mastic tree but once established, give it infrequent deep soakings.
• Prune to shape a mastic tree.

Light

Provide a mastic tree with plenty of bright light. It needs full sun to thrive and produce a healthy amount of gum. Consider placing it somewhere that ensures it receives morning and early afternoon light.

Soil

The perfect soil for mastic trees is a dry, sandy, and gritty mess that many people think is incapable of supporting plants. The mastic will grow in various conditions, but wet soil will not make your tree happy. Make sure your soil is well-draining, and your tree should do great. If not, you can achieve good drainage and proper texture by adding sand and perlite. Mastics prefer alkaline soil. Check the soil's pH to see if it needs amendments.

Water

A mastic tree needs very little watering after it's established. During the first season, water it often to make sure it establishes a good, strong root system. As you head into the next season, overwatering your mastic becomes a concern. Aim for warm, dry soil with deep well-absorbed moisture. Drip irrigation is the perfect way to ensure that the proper amount of water is applied. If this is not possible, then water at the tree base, remembering to water for longer lengths of time but less frequently.

Temperature and Humidity

If you live in an area with high, dry heat and low humidity, then mastic trees are perfect for your yard. Mastic trees are now common in the arid regions of Mexico where it was introduced and has since naturalized. The tree does well in USDA zones 9 to 11, which mimics its native region.

Fertilizer

Giving a yearly dose of a slow-release all-purpose 10-10-10 fertilizer every spring on the first emergence of new growth will really benefit your tree. The soil conditions it prefers lack many organics, so the little addition of some nutrients will give it some added pep.

Pruning

Pruning your mastic may be the most labor-intensive part of owning a mastic tree but it is a necessary one if you'd like to shape it as an ornamental. While small, it will reach no taller than 25 feet and will grow wider than tall. To rein in this wild growth a bit, you will want to keep it well-pruned with some structural shaping. Establish a single individual leader trunk and then you can maintain a manageable canopy from there.

Proceed with pruning using these guidelines and steps:

1. Do all pruning in the winter months while the tree is dormant.
2. Use the right tool for the right cut—pruners for small cuts up to an inch, loppers for anything up to two inches, and a folding saw for things larger than two to four inches.
3. Clean your tools between cuts with a solution made from diluted bleach in a 1-to-9 ratio of bleach and water.
4. Remove the four D's first—branches that are dead, damaged, dying, or diseased.
5. Make structural cuts that will allow for space, air, and room for your tree to grow. Remember that you always want Y-shaped branches and never branches that form an X-shape with neighbors.
6. Prune away shoots and suckers from the base of the trunk. These will grow into new trunks and create a multi-trunked tree.
7. Shape the tree into the desired form.

Propagating Mastic Trees

Commercial growers propagate mastic trees in numerous ways, from grafting to layering. To propagate a mastic tree at home, use hardwood cuttings. Propagating this dioecious plant from seed can prove complicated. Cuttings may be equally complicated because you have to aerate the area you plan to plant the cutting and they may be notoriously tough to root. If you'd like to try this method, take these steps:

• Collect thick branches from a mature tree in the late spring or early summer.
• Dip the wood cutting in rooting hormone.
• Place wood cuttings in containers filled with soil that is well-draining and aerated.
• Put the containers in a cold frame or greenhouse until ready to plant it in the ground.

Common Problems With Mastic Trees

Mastic trees are known for their easy maintenance and pest and disease resistance. However, you may have a few issues with the plant. Watch for these signs.

Yellowing Leaves

A mastic tree with yellowing leaves indicates overwatering. This can also lead to leaf drop and root rot. Pull back on watering to see if this fixes the problem.

Growing Out of Control

The biggest chore that you will face with mastic trees is pruning, which is mainly for aesthetics. Yearly maintenance pruning is vital afterward to ensure the tree's shape and form and keep it from getting out of hand.

Stickiness

The mastic tree leaks a sticky resin from the bark known as gum mastic which has many commercial uses. The better the tree is taken care of, the more gum it produces. However, mastic resin (called "tears") used in commercial products is typically obtained from trees (such as the "Chia" variety) exclusively cultivated on the southern part of Chios, a Greek island in the northern Aegean Sea.