Travel through the arid mountainous regions of the Southwest United States and you will see dark shrubby conifers surrounding you. Their greyish-brown bark creates little respites of shade in the scorching heat.
There is a good chance you found Juniperus monosperma, or the One Seed Juniper. What you are not seeing is that most of the plant is under the ground. This juniper tree grows at a snail’s pace on the surface, while its taproot rockets to depths of up to 200 feet at maturity.
The tree plays an important part in the local ecology, providing a home for wildlife with its shrubby form and its shade provides a microclimate for plants that cannot handle the harsh temperature of the full sun. The One Seed Juniper is adapted to handle the brutal desert climate. It can stop its growth when not enough moisture is available and begin growing again when it is once again available.
The One Seed Junipers common name is inspired by its botanical name (Juniperus monosperma). Mono means one and sperma means seed. The trees cone, often confused with a berry, typically contains only one seed.
The One Seed Juniper is dioecious, meaning it has separate male and female trees. The female will produce mature cones after about five months that are blue to a dark purple. Young plants are often confused with other plants since they have needles instead of the scaled foliage typical of the mature One Seed Juniper.
With the tree being so widely available, it is not surprising that uses have been found for its berries, bark, and needles. The Native American people of the region historically used the plant for medicine, food, dye, shelter, and ceremony for thousands of years.
|Botanical Name||Juniperus monosperma|
|Common Name||One Seed Juniper|
|Plant Type||Tree, Shrub|
|Mature Size||12-35 ft. tall|
|Sun Exposure||Full Sun to Part Shade|
|Soil Type||Sandy, Gravelly, Loose Rock|
|Bloom Time||No Bloom|
|Flower Color||No flower but shows blue to purple berry like cones.|
|Native Range||Southwest United States|
How to Grow One Seed Juniper
The One Seed Juniper is one of those strange plants that are everywhere in its native range but found rarely in the nursery trade - outside of dealers that specialize in native plants or conifers. This is a shame because it is a great plant for growing in xeriscape gardens, and this is where it has really become a star as of late.
Adding this species to your garden is best done by finding a dealer that sells seedlings or saplings. Trying to plant a larger tree or shrub does not usually bring success because of the issues transplanting this species due to the large taproot.
To plant, do as normal when you would plant any other tree or shrub and choose your location knowing the size, and characteristics of what your planting. Consider the utilities and any infrastructure under the plant and think about future improvements.
Once a site is chosen, dig a hole twice as wide as your container is deep and as deep as your container. Do not fertilize the hole when planting, A New Mexico State University study showed that fertilization increases the chances of the tree dying.
Finally, top the hole with water, fill with loose rocky, gravel soil, and cover the area with mulch. Keep the tree watered, protect it from high wind and critters for the first year or two with stakes and trunk guards, and you will be amazed at how maintenance-free this tree is.
This plant grows in the desert, so it is no stranger to bright glaring sun. It can adapt enough to also deal with part shade. You can thank the high walled desert canyons and cliff faces for providing the shade to allow the One Seeded Juniper to adapt to multiple conditions. When a plant must contend with triple degree temperatures, 60° temperature swings, and months without rain it needs to be adaptable.
The ideal soil for this plant is a loose inorganic mix that is neutral to slightly alkaline. A sandy, gravel pumice mixture is perfect if you are looking to add to your soil to make a more hospitable mix. Again, this tree is adaptable, and it is not particularly picky.
As mentioned, this plant is perfect for xeriscaping. It does not require much watering and is exceptionally drought tolerant with the ability to shut off growth till water is available.
Temperature and Humidity
The One Seed Juniper is a desert native, It enjoys hot dry climates with occasional rain. It is frost hardy and will do well in Zones 5-8 but its native range is hot.
One Seed Junipers require no fertilizer. Amend the soil after testing if you find the soil acidic to be too alkaline, but there is no real need to feed this plant.
Potting and Repotting One Seed Juniper
Though notoriously hard to transplant, with luck and some knowhow, One Seed Junipers can be potted and used in the art of Bonsai. To best do this, purchase a seedling or sapling and plant in a pot just large enough for its roots. Use a premixed bonsai soil that usually consists of pumice, vermiculite, and crushed lava. Once established, you can repot by removing the soil from the roots and moving into a larger pot and trimming and shaping the tree as you feel inspired.