How to Grow and Care For a Mastic Tree

The mastic tree (Pistacia lentiscus) is a broadleaf evergreen that favors the arid, rocky conditions you will find in the hills of Mediterranean countries of its native range. The ancient tree has been used in craft and the kitchen since ancient times and continues to be used today for cooking (really , it's used to make iced cream!) and in a new role as an ornamental tree in gardens in hot, dry climates.

In the areas where the weather allows it, primarily in the western United States, mastic will be a good option for those looking for a slow-growing shrublike tree that requires almost no water at all once established.

Mastic trees are dioecious, meaning that both male and female trees are needed to produce the showy red fruit. The trees bloom in spring, and although it is related to pistachio, the fruit isn't tasty for humans. However, wildlife love the fruit. Female flowers are followed by red berries, which turn black when ripe.

Mastic Tree Care

Growing a mastic tree is going to get you into some sticky situations—really. The tree leaks a sticky resin is known as gum mastic. It is used in cooking, medicine, and to bind books. The better the tree is taken care of, the more gum it produces; luckily, the tree is easy to care for. The biggest chore that you will face with mastic trees is pruning, which is mainly for aesthetics.

The greatest challenge when growing your tree will be learning how to water it. You were taught that trees need water to thrive. Although young, newly planted trees need water to get established, once the mastic tree has been growing a few years, you will need to learn not to overwater or water any more often than an infrequent deep soaking. Think about sunbaked Greek and Sicilian mountainsides: consider the dryness of that native ecosystem for a second, and then put down the hose and let your tree bake for a bit.

Light

When growing a mastic tree, you will want to provide it 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. Another consideration is pH. Mastics prefer alkaline soil, so checking the pH might be a good idea; you can do a pretty easy test for it that will let you know If you need to amend the soil.

Water

After your tree is established, it will need very little watering. During the first season, you will want to water it often to make sure it does establish a good, strong root system. As you head into the next season, overwatering your mastic becomes the concern. What you should be aiming for is 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 longer lengths of time, less frequently.

Temperature and Humidity

If you live in an area where you can use the line, "But it's a dry heat," then mastic trees are perfect for your yard. Common now in the arid regions of Mexico where it was introduced and has since naturalized, the mastic tree excels in conditions of high heat and low humidity. It does fantastic in USDA Zones 9-11, 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. While small, reaching no taller than 25 feet, the tree will be shrubby and can grow wider than it is tall. To rein in this wildness a bit, you will want to keep it well-pruned with some structural shaping. The first thing you will need to attend to is assuring that you establish a single individual leader trunk. Once this step is done, you will then be able to maintain a somewhat manageable canopy.

Yearly maintenance pruning is vital afterward to ensure the tree's shape and form and keep it from getting out of hand. How you want to proceed is easy:

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 inches up to up to four.
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. Remembering 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.