Junipers are coniferous plants with green, needle-like leaves. There are many different juniper cultivars available, and each may have its own particular needs. A few planting and care requirements are consistent throughout the species, however.
Part One: Preparations
Choose the best variety. There are many different juniper cultivars, each with a different appearance and size, so you’ll need to choose one that suits your taste and space appropriately.
Low growing varieties grow 2 feet (61 cm) high or less. Some examples are: Sargentii, which has green foliage and spreads to 7 feet (2.1 m)
Plumosa Compacta, which spreads to 8 feet (2.4 m) and has gray-green foliage in the summer and bronze-purple foliage in the winter
Wiltoni or Blue Rug, which spreads to 8 feet (2.4 m) and has silver-blue foliage
Shore juniper, which has yellow-green foliage and spreads to 8 feet (2.4 m)
Medium growing varieties reach heights between 2 and 5 feet (0.6 and 1.5 m). Several common cultivars include:
Sea Green, which has arching dark green foliage that spreads out as far as 8 feet (2.4 m)
Saybrook Gold, which spreads to 6 feet (1.8 m) and has bright gold needle-like foliage
Holbert, which has blue-tinted foliage that can spread as wide as 9 feet (2.7 m)
Large growing varieties tend to reach heights between 5 and 12 feet (1.5 and 3.7 m). A few example include:
Aureo-Pfitzerana, which has yellow-tinted light green foliage that spreads as far as 10 feet (3 m)
Pfitzeriana, which has bright green foliage that spreads out to 10 feet (3 m)
Blue vase, which has steel blue foliage that grows out to 5 feet (1.5 m)
Purchase a small established shrub. If you want to add juniper to your garden, you should buy young juniper plants from a local garden center. Juniper plants can be grown from seed or propagated through cuttings, but the process is time-consuming and difficult, so it is not recommended for the average gardener.
It is also more difficult to find seeds and cuttings than it is to find a young established plant.
Look for a sunny location. Junipers do best with full sun, but they can also survive well in partial shade.
Areas that are mostly shaded should be avoided. Junipers planted in the shade tend to open up and thin out. They may also face more problems with pests and diseases.
You should also avoid sites that are directly next to lawn sprinklers or similar sources of irrigation. Heavy, frequent watering can drench the soil too severely for your juniper plant.
Examine and amend the soil. Most juniper varieties tolerate a wide range of soil conditions, but the soil must be well-draining. If it isn’t, you should amend the soil to improve its drainage abilities before planting your juniper.
The pH of the soil does not matter much for most varieties.
Most varieties can manage well in dry, clay-based soils and standard soils. Some can even grow in sand or notably salty soils.
If the soil is heavy and drains poorly, you should dig several buckets of gravel or grit into the intended planting area prior to the planting period. Either material should help improve drainage conditions.
While it is not necessary, if you want to make the soil more nutrient-dense, you may also wish to add a bucket of organic material, like leaf mold, rotted manure, or compost. Dig it into the planting site shortly before you intend to plant the juniper.
Part Two: Planting
Water the juniper in its container. Thoroughly water the juniper in its container, soaking the soil and making it more compact.
Feel the soil in the container before you do this. If it already seems very moist and very compact, you should skip this step.
Watering the soil reduces the amount of air in the container and makes it easier to remove the root ball.
Dig a large hole. Use a shovel or spade to dig a hole that is twice as wide and at least as deep as the container the juniper plant is currently in. There needs to be plenty of space. If you make a hole that is just barely big enough, the roots may not settle and establish themselves well.
Mix in a balanced fertilizer. Mix 2 tsp (10 ml) of a balanced 10-10-10 fertilizer into the soil for every 1 gallon (4 L) plant.
Note that a 10-10-10 fertilizer refers to a blend containing equal parts nitrogen, phosphorus, and potassium.
You should either mix the fertilizer into the soil at the bottom of the hole or spread it around the outside of the hole. Do not lay the fertilizer directly inside the planting hole.
Remove the plant from the container. If the plant is in a disposable plastic container, carefully tip the container on its side and press around the outside to loosen the soil and root mass inside. You should be able to carefully slide the entire soil mass out of the container with your hands or shovel.
If the plant is not in a disposable plastic container, you may need to loosen the soil around the sides of the container by gliding your shovel around the inner perimeter.
Loosen the root mass. Use your hands or a dull knife to separate the individual roots from the compacted mass. Loosen as many of the roots as possible without damaging too many.
You do not need to tease out all of the roots, but the longer ones at the bottom of the root ball should be loosened from the mass. This will help the roots spread into the surrounding soil as you plant the shrub.
Place the root ball into the hole. Place the root ball in the center of the hole you dug. The top of the root ball should be level to the surface of the soil around the hole.
The soil level should be about the same as it was in the pot. If you discover that the planting hole is too deep, take the plant out and add more soil before putting it back in. If the hole is too shallow, remove the plant and dig the hole deeper before returning it.
Fill in the rest of the hole. Hold the shrub steady and upright while you fill in the hole around it with some of the soil you removed while digging the hole.
You can also add some organic matter during this time, but that is strictly optional.
Pat down the soil with your hands or feet to settle it and remove any air pockets. Do not stamp the plant into the ground, however.
Leave plenty of space in between plants. When junipers are planted too close together, a thick layer of foliage can form, causing problems with air circulation. As a result, the plants are more likely to face problems with pests and diseases.
This can be a problem for all juniper varieties, but it is especially problematic for horizontal growing varieties.
The exact amount of space you need to leave in between juniper plants will vary based on the type and size of the variety you choose. Consider how far the shrub spreads and space the plants wide enough apart to prevent them from spreading into each other.
Water thoroughly until established. Give the plant plenty of water immediately after you finish planting it. Doing so will help the plant establish itself while further compacting the soil.
Continue to water the plant twice a week for the first month to help it establish itself.
Part Three: Care
Avoid over-watering. Established juniper plants only need to be watered during periods of severe drought.
These plants are fairly drought tolerant, so you should be able to leave them alone during minor droughts.
Junipers can actually weaken if you water them too often. Soggy soil and water-logged roots make the plant more susceptible to diseases and pests.
Apply fertilizer twice a year. Fertilizer should be mixed into the soil around the junipers once in the early spring. Apply fertilizer once more in the late summer.
Use 1/2 lb (225 g) of fertilizer per 100 square feet (9.23 square meters).
For best results, apply the fertilizer immediately before an anticipated rainfall. If this is not possible, water the area thoroughly after application.
Select a 16-4-8 or 12-4-8 fertilizer. These two types have a large amount of nitrogen (represented by the “16” and “12”), which helps the juniper produce more chlorophyll to grow faster. The phosphorus (“4”) is minimal since phosphorus primarily helps with flowering ability. The potassium (“8”) is mid-range and helps protect the plant from disease while improving root development.
Prune lightly. You only need to prune old, dead foliage that builds up underneath creeping juniper varieties. Clearing out dead wood improves air circulation, leading the a healthier plant.
You can also prune the tips of the plant as they bud to limit the height and reach of the plant.
If the plant becomes too bushy or dense, you can thin out some of the older wood, as well.
Wait until new growth has begun to sprout in the spring before doing any pruning.
Since the needles can be painful, you should wear gloves and long sleeves while pruning the plant.
Do not do any heavy pruning, however. Not much new growth develops on old wood, so if you cut the wood back to its large limbs, that wood will not grow back and the plant will remain bare.
Watch out for common pests. Junipers can develop problems with insects, including bagworms, spider mites, leaf miners, webworms, and aphids. Most of these pests can be controlled with pesticide. Wait until you see a problem, then purchase a pesticide labeled for use against that pest and apply as directed on the label.
If you see carrot-shaped bags forming on the needles of your juniper, you likely have a bagworm problem. You can physically remove these bags to prevent the larvae from hatching and eating the needles.
Spruce spider mites can be especially problematic since they come in heavy infestations and cause massive needle browning and death. Chemical intervention is almost always necessary.
Twig borers can be detected when branch tips brown and die. Webworms can be detected when you see heavy webbing and browning of the foliage. Both of these must be treated with pesticides, as well.
Be aware of common diseases. Junipers planted in ideal conditions rarely have trouble with disease, but some diseases can occur, especially during particularly rainy or shady seasons.
Twig and tip blight can be avoided with proper air circulation, but if you notice it, you should quickly remove any infected branches. Apple cedar rust can develop when apples or crabapples are planted near junipers. If you see it, remove the infected portions of the plant immediately.
Phytophthora root rot results in the sudden death of the entire plant and cannot be treated after it develops. It can be prevented by planting the juniper in raised beds or well-draining soil.
Scale appears on stems and leaves and can be minimized by applying dormant oil in the spring or at first sight of a problem.
Things You’ll Need
Gravel or grit
Shovel or garden spade
Balanced 10-10-10 fertilizer
Secondary 16-4-8 or 12-4-8 fertilizer
Pesticides (as needed)
Sources and Citations
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