Alligator Juniper (Juniperus deppeana) Profile

Written by Iris

Aug 10 2021

Alligator Juniper (Juniperus deppeana) Profile
Alligator Juniper (Juniperus deppeana) is an evergreen conifer, so named for its distinctive wrinkled, scaly bark. Alligator Juniper (Juniperus deppeana) grows about 20 to 40 feet tall in a home landscape, but can reach a height of 65 feet. Alligator Juniper (Juniperus deppeana) grows best in a slightly acidic soil with plenty of sun and good drainage, but it can tolerate a variety of soil conditions. Grow Alligator Juniper (Juniperus deppeana) in U.S. Department of Agriculture plant hardiness zones 7 through 9.

Alligator Juniper (Juniperus deppeana) Picture

 Alligator Juniper

Alligator Juniper (Juniperus deppeana) Info

Botanical Name Juniperus deppeana
Common Name Alligator juniper, checkerbark juniper, western juniper
Plant Type Evergreen tree
Mature Size 50' tall
Sun Exposure Full sun
Soil Type Dry, well-draining
Soil pH 5.5 - 7.0
Bloom Time Winter

Ecological Habits of Alligator Juniper (Juniperus deppeana)

While this is the largest southwestern juniper, ranging in heights from 20 to 50 feet, it is very slow growing. It has a dense rounded or pyramidal crown with a spreading canopy. This evergreen tree sits on a single massive trunk but can be multi-trunked. The leaves are bluish green, pointed, and sacle-like. They are about 1/16 of an inch long and form on dense branches. The cones or berries are reddish-brown beneath a waxy gray coating. They are hard and approximately ½ inch in diameter. The berries generally have 3 to 5 seeds and do not mature until the second year. The bark is strikingly checked, in an almost alligator like pattern.
Alligator Juniper

Alligator Juniper (Juniperus deppeana) Hirstory

This species of juniper is native to the southwestern United States and Mexico. It received its common name from the thick, checkered, furrowed bark which is divided into scales that resemble the skin on the backs of alligators. This species is very slow growing, but lives typically from 500 to 800 years, with records of 1100 and 1400 years. Birds and mammals enjoy the berries of the juniper, which are available at times when other food is scarce.
The species name deppeana honors Ferdinand Deppe (1794-1861), a German naturalist and painter who collected plants in Mexico, California and Hawaii for the Berlin Museum. The tree was first collected in the Zuni Mountains of northwestern New Mexico back in 1851 by Dr. Samuel Washington Woodhouse (1821-1904), the surgeon/naturalist on the Sitgreaves Expedition to the Colorado and Zuni rivers.

Alligator Juniper (Juniperus deppeana) Distribution Area

Growing in oak and pinyon-juniper woodlands in Arizona, New Mexico and Texas and into Mexico, these trees grow at elevations between 4,500 and 8,000 feet. The trees may produce multiple stems from a stump, and a single-trunked specimen might reach 65 feet tall.
Alligator Juniper

How to Grow and Care for Alligator Juniper (Juniperus deppeana)

How to Grow Alligator Juniper (Juniperus deppeana)

  • With Seeds
Indoor Planting: If your alligator juniper seeds require stratification or scarification – do the recommended pretreatment before planting indoors.
Planting Instructions: Fill a container with Alligator Juniper seed starting mix to about ½ inch from the top. Place your Alligator Juniper seeds 1 inch to 1 ½ inches below the soil surface. Gently water the Alligator Juniper seeds to keep moist, not soaking wet. Germination may occur in 1 week or as long as 3 months (depending on the species). Place the seed container on a heat mat under growing light. Keep your growing lights on 14 hours per day. Keep your heat mat on 24 hours per day. Once your Alligator Juniper seeds germinate, move each seed into its own container under the growing lights and on the heat mat. Keep your seedlings indoors for 2-3 months before transplanting outdoors in the spring (May to June).
Outdoor Planting: If your Alligator Juniper seeds do not require stratification: the best time to plant alligator juniper tree seeds outdoors is after the last frost in your area (spring). In the Northern states – the best time to plant seeds outdoors is from May to June. If your Alligator Juniper seeds require pretreatment: you should plant your seeds outdoors before the ground freezes in your area (late September to early November). Your Alligator Juniper will naturally stratify during the cold winter. Germination usually occurs in May or during the spring season.

Steps for Alligator Juniper (Juniperus deppeana) Propagation with Cuttings

Fill a clean 1 gallon planter with a soil-less potting medium. Make a 1-inch-diameter hole for each Alligator Juniper cutting.
Cut an 8- to 10-inch long stem off of the juniper with pruning shears. Choose a healthy branch that grew in the summer that has plenty of needles growing at the tip.
Remove the needles on the bottom 2 inches of the cut branch. Make 1- to 2-inch slits through the outer layer on each side of the bared stem with a sharp knife. This allows the Alligator Juniperbranch to absorb more water and hormone for root growth.
Place about 1 teaspoon of rooting hormone in a dish. Dip the end of the juniper cutting in the hormone and roll the bare end in it. Coat it thoroughly and shake off any excess.
Stick the hormone-covered section of the branch into a hole in the prepared planter. Firm the potting mix around the cutting, keeping it upright. Mist the medium until it feels moist all the way through.
Place four small 12-inch stakes around the edges of the planter. Cover the Alligator Juniper with plastic film to maintain a consistent humidity. Sit the planter in a spot that receives indirect light and a temperature range of 60 to 65 degrees Fahrenheit. A heating mat placed under the planter at around 70 degrees Fahrenheit increases the chance of root development.
Mist the cutting daily. Start checking for root development with a very gentle tug after four weeks. Transplant each rooted juniper cutting into a 4-inch pot.

How to Care for Alligator Juniper (Juniperus deppeana)

  • Light
True to its native habitat, the alligator juniper is a sun-loving tree that requires full sun in order to thrive. Alligator junipers cannot grow in the shade, and growth may be stunted in areas that only receive partial sun.
  • Soil
Alligator Juniper trees tolerates a wide range of soils, including clay, however prefer a well-drained sandy clay or loam. As with so many other ornamental plants, constantly soggy or wet soil can be problematic. So make sure to plant your Alligator Juniper in a well-drained site. Alligator Juniper trees grow best in a moderately acid to slightly alkaline soil ranging between 6.0 to 7.5 on the pH scale. Most average garden soils fall between a pH range of 6.0 to 7.0.
  • Water
The Alligator Juniper is considered a drought-tolerant tree with low water requirements. Mature alligator juniper should not need additional watering, however, seedlings and saplings may need watering during dry periods. It is important to note that Alligator Juniper is prone to overwatering. Making sure trees are planted in well-drained soil is important to prevent this.
  • Temperature and Humidity
Alligator Juniperis not an overly hardy juniper and can only tolerate freezing temperatures for a short period of time. In extreme cases, the alligator juniper can withstand temperatures as low as -8 degrees Celsius (or 17 degrees Fahrenheit) when fully dormant. These junipers grow best in USDA zones 7 through 9.
  • Fertilizer
Like most juniper trees, the Alligator Juniper does not need to be fed heavily. However, once established, Alligator Juniper can benefit from annual feeding with slow-release bush and tree fertilizer. Alternatively, alligator juniper also responds well to organic fertilizers and soil amendments. Feed the Alligator Juniper in late winter or early spring as the tree is coming out of hibernation to help kick-start their growing season.
  • Pruning
Alligator Juniper are hardy shrubs that can take severe pruning, but it is possible to kill them by pruning them back too far. Alligator Juniper can be pruned at any time, but do heavy pruning in winter or early spring before growth starts. If the Alligator Juniper is severely overgrown, it may be preferable to replace it.

Uses of Alligator Juniper (Juniperus deppeana)

The wood of this species is fragrant with attractive grain and color, which makes it well suited for the making of novelty items such as bookends and small chests. The wood is also used commonly as firewood because it is light, easy to split, has a high heat value, and gives off a pleasant aroma when burned. The wood is also occasionally made into particle board. The J. deppeana is outstanding by itself, as a background or screen, a median, and even a buffer for plantings.

Varieties of Alligator Juniper (Juniperus deppeana)

There are five varieties of alligator junipers:
Alligator Juniper var. Deppeana
Alligator Juniper var. pachyphlaea
Alligator Juniper var. robusta
Alligator Juniper var. sperryi
Alligator Juniper var. zacatecensis

Alligator Juniper (Juniperus deppeana) Common Pests/Diseases

Alligator Juniper is susceptible to many common pests and diseases. Common juniper diseases include shoot and leaf blight, and cedar rust. Microbicides can help proactively protect alligator juniper from such diseases, but they should be used before infection appears. These common diseases can be controlled by timely pruning any dead or diseased branches.
Common pests of alligator juniper include marsupials, spruce tetragmites, and juniper scales. Insecticides are an effective way to control serious infections of any of these common pests, but the best form of control is prevention. Get in the habit of checking Alligator Juniper regularly for pests so that any pests can be detected and managed early.

Alligator Juniper (Juniperus deppeana) Companion Plants

Alligator Juniper combine well with a wide variety of trees, shrubs, perennials and groundcovers. Plant alongside companions with similar cultivation needs, such as dwarf bamboo, sage, roses, and ornamental grasses.