When planted right and in the right spot, Juniper trees are exceptionally easy to grow. Their upright habit and dense foliage makes Juniper trees an ideal selection for a dense privacy screen or windbreak, to mark each side of an entry way, as a specimen, or to frame in the corners of a home or other structure in the sunny landscape. They are excellent additions to Asian Gardens, Bird Gardens, Conifer Gardens, Rock Gardens, Xeriscape Gardens (Low Water Needs).
Here's a breakdown of what you need to know for how to plant and care for Juniper trees...
Cultural Preferences
Soil Preferences
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 Juniper in a well-drained site.
How To Test Soil Drainage
If you are uncertain about soil drainage in the area you intend to plant your Juniper, it's well worth taking the time to test the drainage before planting. To test soil drainage, dig a hole 12" wide by 12" deep in the planting area. Fill the hole with water and let it drain. Then, after it drains, fill it with water again, but this time clock how long it takes to drain. In well-drained soil the water level will go down at a rate of about 1 inch an hour. A faster rate, such as in loose, sandy soil, may signal potentially dry site conditions and possibly a need to add organic matter to help retain moisture. A slower rate indicates poor draining soil and is a caution you need to improve drainage, plant in a raised mound or bed, or look for plants that are more tolerant of wet or boggy conditions.
Soil pH
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.
How To Test Soil pH
Soil pH is a measurement of the alkalinity or acidity of soil and is measured on a scale of 1-14, with 7 as the neutral mark. Any measurement below 7 indicates acid soil conditions, and anything above 7 indicates alkaline.
If you're unsure about the pH of your soil, and whether or not it's suitable for growing Juniper trees, it's a good idea to test the soil pH in the planting area. You can quickly test soil pH with an inexpensive soil pH tester probe. To raise the pH (make more alkaline) you can add pelletized limestone to the soil. To lower the pH (make more acid) you can apply Soil Sulfur, Aluminum Sulfate, or Chelated Iron. Adding organic compost to the soil or using compost as mulch can also help to increase acidity and maintain acid soil conditions.
Learn More: What is Soil pH and How To Adjust It?
Light Preferences
Juniper trees prefer as much sun as you can give them. At least 6 to 7 hours of direct sunlight per day is suggested.
How To Plant A Juniper Tree In The Ground
Scroll down for container planting instructions and care tips
Step 1
Start by digging your planting hole at least two to three times as wide and not much deeper than the root ball of the plant. The wider the hole the better. Place native soil removed from planting hole around the perimeter of the hole, in a wheel barrow, or on a tarp.
Step 2
Depending on the type, fertility and porosity of the soil in the planting area you might need to amend the native soil. When planting in dense clay or other compacted soils it is beneficial to thoroughly mix in some bagged top soil, sand, and/or a good planting mix at a 50/50 ratio with the native soil removed from the planting hole. When planting in very sandy, quick-draining soil you might want to consider mixing in some top soil to help retain some moisture. When planting in well-drained soil of average fertility there is no need for adding a soil amendment.
Step 3
To remove your Juniper from the container it was growing in, first squeeze or tap on the sides of the container to loosen the root ball. Then grasp the base of the plant and try to gently lift and remove the root ball from its container. If the root ball is stuck in the container use snips or a utility knife to cut the container away. After having removed the plant from the container, loosen some feeder roots around the surface of the root ball. If your plant is root bound, use a stream of water from the garden hose to remove some of the soil from the side and bottom surface of the root ball. This should help to expose and loosen some feeder roots.
Step 4
Set your Juniper in the planting hole so that the top edge of the root ball is at or slightly above ground level. If necessary, add some backfill soil mixture to the bottom of the hole to achieve proper planting height.
Note: If the soil is poorly drained (constantly soggy or wet) improve drainage in the planting area or consider planting another plant species tolerant of wet soils.
Step 5
After setting your Juniper in the planting hole, use one hand to hold the plant straight and your other hand to begin back-filling your soil mixture around the root ball, tamping as you go to remove air pockets. When you have filled the hole to the halfway point you can soak the soil. Then continue back-filling to the top edge of the root ball. To avoid suffocating your plant, do not put any soil on top of the root ball.
Step 6
Immediately after planting deep soak the soil in the planting area, including the root ball, to a depth equal to the height of the root ball. For an extra boost, you can water your newly planted Juniper with a solution of Root Stimulator, which stimulates early root formation and stronger root development, reduces plant shock, and promotes greener, more vigorous plants.
Step 7
To help conserve moisture and suppress weed growth, apply a 1 to 2" layer of shredded or chipped wood mulch or pine straw around the planting area. Avoid using freshly chipped or shredded wood for mulch until it has cured in a pile for at least 6 months, a year is better. Avoid placing or piling mulch directly against the base of your Juniper tree as this could cause the bark to rot.
How To Plant A Juniper Tree In A Container
Junipers growing in pots appreciate a moist but well-drained soil. Constantly soggy soil can and often will cause root rot or other harmful or deadly plant diseases. Therefore, I suggest using a quality potting soil or potting mix, or a 50/50 combination thereof and a container with a drainage hole(s). You can also add 10 to 20 percent pumice or Perlite to the soil mixture to help with drainage.
As mentioned, choose a container with drainage holes at the bottom and also one that is large enough to allow for 2 to 3 years of growth before shifting up to a larger size container. This might mean your planting pot would be 8 inches or more in diameter (width) than the root ball of your plant.
Container color will matter as well. Not only will you want to pick a color of container that goes well with the foliage color of your Juniper, you'll also want to pick a container that matches the style of your home or other structures and other plants in the surrounding environment.
Many nursery & garden centers offer a wide variety of containers to choose from. Before heading out to buy a container take pictures of your home and the surrounding environment. Doing so will help you to choose just the right color and style.
Container Planting Instructions
Step 1
Before filling your container with the soil mix, I suggest lining the bottom of the container with shade cloth or a porous landscape fabric. This will keep the drain holes from becoming stopped up with soil. If you place gravel or other materials in the bottom of the pot lay the fabric over it.
Step 2
To remove your Juniper from the container it was growing in, first squeeze or tap on the sides of the container to loosen the root ball. Then grasp the base of the plant and try to gently lift and remove the root ball from its container. If the root ball is stuck in the container use snips or a utility knife to cut the container away. After having removed the plant from the container, loosen some feeder roots around the surface of the root ball. If your plant is root bound, use a stream of water from the garden hose to remove some of the soil from the side and bottom surface of the root ball. This should help to expose and loosen some feeder roots.
Step 3
Pour a small amount of your soil mixture in the bottom of the container. Set your plant in the container and make necessary adjustments by adding or removing some soil so that the top edge of the root ball will sit 1/2 to 1" below the rim of the container.
Step 4
Backfill with your potting soil around root ball, tamping as you go, until the level of potting soil is even with the top edge of root ball.
Step 5
Water thoroughly until water starts to drain from the holes in the bottom of the container. Add more potting mix if settling occurs during watering.
Step 6 (Optional)
Apply a 1/2" layer of wood chips or sphagnum moss to soil surface to help conserve moisture. Stone mulch can also be used.
How To Care For A Juniper Tree
Feeding - Watering - Pruning
Junipers are light feeders however will benefit from fertilization.
When to fertilize a Chaste Tree?
I fertilize my Juniper trees in late winter or very early spring.
What type of fertilizer?
In The Ground - To maintain good foliage color and support growth and overall health of the plant, feed in spring with a slow-release shrub & tree food, preferably one containing iron and/or sulfur. Alternatively, you can feed with a natural organic plant food. To avoid stimulating new growth that could be damaged by an early frost, cease fertilization two months prior to the first frost date in your area.
To conserve moisture throughout the growing season and suppress weed growth, I also always apply a 1 to 2" layer of cured, shredded or chipped wood mulch or pine straw around the tree in late winter. As the mulch decomposes it will add vital nutrients to the soil that your chaste tree will appreciate.
Note: Avoid the use of freshly chipped wood for mulch until it has cured in a pile for at least 6 months, a year is better. Avoid placing or piling mulch directly against the base of your plant as this could cause the bark to rot.
In Containers - Feed Junipers growing in containers with a slow-release granular fertilizer or a all-purpose iquid plant food listed for use in containers. Follow instructions on product label.
How much fertilizer?
This will depend of course on the size of the Juniper tree you are fertilizing and the type of fertilizer. Regarding slow-release shrub and tree fertilizers, you'll find application instructions on the package label.
Where to spread the fertilizer?
The root system of a Juniper tree might grow 2 to 3 feet deep but the majority of the feeder roots responsible for absorbing nutrients are in the top 12 to 18 inches of soil. Spreading fertilizer on the soil surface is sufficient to reach these feeder roots.
Spread fertilizer evenly around each tree, beginning a couple feet from the trunk, and then one foot beyond the drip line (branch perimeter) for every 5 feet in tree height.
Note: If the soil is compacted or subject to excessive water runoff, the fertilizer can be applied in a series of holes 6 to 8 inches deep in the same area with about five holes per 1 inch of trunk diameter.
Soil pH - Juniper grows best in a slightly acid to slightly alkaline soil ranging from 6.0 to 7.5 on the pH scale. Most average garden soils fall between a pH range of 6.0 to 7.0.
Learn More: What is Soil pH and How To Adjust It?
How To Water A Juniper Tree
When young, Juniper trees will require some water to establish roots. That said, when established they are exceptionally drought tolerant. As with so many other types of ornamental plants, constantly soggy or wet soil conditions can cause root rot and other harmful plant diseases. So be careful not to over-water!
Note: When watering with an automated irrigation system it's best to set your timer to water during the early morning hours and not in the late evening or at night, which can lead to the onset of fungus and other foliar diseases. Test the soil moisture often during the first few weeks after planting and adjust irrigation time if necessary to maintain a moist but not wet soil.
At Planting Time
Immediately after planting deep soak the soil in the planting area, including the root ball, to a depth equal to the height of the root ball. For an extra boost, you can water your newly planted Juniper with a solution of Root Stimulator, which stimulates early root formation, stronger root development, reduces plant shock, and promotes greener, more vigorous plants.
During the First Active Growth Season
In average garden soil you should not have to water your newly planted Juniper every day. More often than not, this causes soggy soil conditions that can cause root rot and other harmful plant diseases. In the absence of sufficient rainfall, water only as needed to keep the root ball and surrounding soil damp to moist.
Keep in mind that deep soaking less frequently, allowing the soil to dry out somewhat before watering again, is much better than splashing just a little water on the plants every day.
Thereafter
When well established, Juniper are very drought tolerant. Rarely if ever will they require supplemental irrigation.
How To Prune A Juniper Tree
If you provide enough space for a Juniper to grow to it's mature size, no pruning is necessary. That said, Juniper can be pruned to remove a stray or damaged branch, lightly for shaping purposes, or to form very interesting topiary forms such as poodle tier, pom pom and spirals.
When to Prune
Since junipers and other conifers produce new growth in spring and fall, and do not grow much in summer, prune them in early spring in warm regions or early summer in cooler regions. The only exception to this rule is pines, which should be pruned before the candle growth develops in the spring.
How to Prune
With the exception of topiary, which is the method of frequent trimming to a formal shape: spiral, poodle tier or pompom, prune Juniper trees according to their growth habits.
When pruning a Juniper tree it is a matter of cutting the branches so that a more desirable plant is attained through compact, controlled growth, while leaving the natural shape of the plant. This requires selective pruning of individual stems rather than indiscriminately shearing with hedge trimmers. Shearing not only ruins the natural growth habit but prevents light from penetrating into the center of the plant resulting in foliage drop.
Important Note: When pruning any Juniper avoid cutting back to a point of bare wood, or, in other words, beyond green foliage on branches or stems. Since few leaf buds are formed on older branches or stems, the plants may be damaged beyond repair if you cut too far.
There are certain general rules to follow for various types of conifers:
Start pruning when plants are small, usually the first year after they come from the nursery. Then, if they are pruned a little each year, severe pruning, which can harm conifers, is not necessary.
Damaged or dead branches should be removed when they occur. Cut damaged branches off just beyond the break. New foliage from surrounding branches will usually fill in these gaps. Remove dead branches at their origin.
The tips of branches can be pruned each year to keep plants in check and induces a smaller, more compact plant.
If you don't want to destroy the natural shape of upright growing conifer, do not cut the central leader (top vertical branch), except to remove a multiple leader. This may occur when the plants are young. Remove all but one of the leaders, leaving the straightest and strongest.