Juniper trees were one of the first in my garden, and it is not surprising, for many years, these beautiful plants have been cultivated around the world. Every year, breeders produce new cultivars with increasingly attractive decorative features.
Like most gardeners, I try to reproduce unusual varieties on my own to have more than one copy in the garden.
Today we’ll talk about how to propagate Juniper. I will tell you about my achievements and failures, and I will try to describe my whole experience in as much detail as possible.
1. Propagating Juniper From Cuttings
First, let’s talk about the time when it is best to root juniper cuttings. Time plays a crucial role in this process.
The best time to root juniper cuttings is the end of winter or the beginning of spring, depending on the weather and climate. The plant should only come out of hibernation. At this time, it is best to cut the cuttings. There must be no new growth.
I have tried rooting cuttings several times with young shoots, and I have never succeeded in doing so. If you live in cold conditions, then the cuttings can be prepared a little later, for example, in late March or early April.
The second favorable period for rooting is the end of September or the beginning of October. At this time, the plants are no longer growing, and the young growth is ripe. Before the first frost cuttings, in most cases will form the root system.
If in the fall, the cuttings do not have enough time to root, then they will form a callus, which they can also draw water. In this state, they overwinter and continue to grow in the spring.
Do not try to root Juniper in summer, especially in July. It is too hot at this time, and you will not be able to provide the right conditions. All my attempts to root at this time failed.
Also, I do not recommend rooting in winter. I once tried to root Juniper and thuja in the basement in the winter. Humidity and temperature were appropriate. However, it was too dark there, so I installed the backlight.
By the spring, some cuttings took root, and some did not. The downside was electricity and lighting costs. In a word, it was troublesome and costly.
Before harvesting cuttings, you can do a few tricks. Sprinkle Juniper with liquid fertilizer a week earlier. This fertilizer should contain a lot of phosphorus. This will saturate the needles and branches with the necessary substances for better rooting.
Second, water the plant well the day before pruning. Water the plant thoroughly, wet the branches and needles. The idea is to saturate the plant with a maximum amount of water.
It is best to cut in the morning, and it is also advisable that the day is cloudy.
You will need a hand pruner, a sharp knife, and a saw. Sharpen and disinfect all tools.
If possible, use a saw or hand pruner to cut a large branch with small branches that will fit as cuttings. If not, separate the cuttings straight from the bush.
The cuttings should be thick enough. The diameter of the twigs should be at least 0.2 inches. The thinner cuttings will not root, or there will be a low success rate. Cuttings with a diameter greater than 0.5 inches are also poorly rooted. The length should be at least 2 inches.
Take the cuttings off the main branch in a sharp motion. On the opposite end should remain “heel”. In the photo above, you can see how the cuttings should look. It should have enough needles on one side and a “heel” on the other.
The fact is that if you separate the cuttings in the place where it is attached to the main branch, you store enough cambium on it. Cambium is the tissue from which the roots will form.
Peel the bottom half of the cuttings from the needles. Try not to damage the bark and tissue at the lower end.
For rooting Juniper, soil based on peat is best. It must be sterile without fungi. You can buy soil for seedlings at the supermarket.
You can also make the substrate yourself. You need peat and land to do this. The earth should be sterilized using high temperatures. You can use the oven to do this.
Next, mix one half of the peat with half of the sterile soil. Add some water to keep the substrate moist.
Many recommend adding sand or perlite to improve the breathability of the soil. I have never done this, and I have had excellent results. So if you wish you can do it, if not then don’t bother. Peat will make the substrate sufficiently breathable.
It is best to choose trays for plants as containers. You can also use regular plastic pots. The depth of containers should be at least 5 inches. If the cuttings are large, then choose deeper containers.
It is important that there are drainage holes in the containers. If there are no holes, making them with a knife or drill.
Trays or square pots are preferable because the cuttings can be placed more compactly.
Before planting cuttings, spray the soil surface with an aqueous solution of fungicide. This will keep them from rotting.
A few words I want to say about different types of rooting hormones: in fact, it is not necessary to use them at all. I tried different kinds and didn’t notice much difference except rooting gel.
Honey, aloe, and other folk methods do not affect the rooting process. I tried almost all of them, and the number of rooted cuttings did not increase.
My next discovery was a rooting powder that contained Indole-3-butyric acid. To be honest, there was no noticeable effect either. Healthy-looking cuttings were powdered and not rooted, while others without powder formed healthy roots. So I do not recommend spending money on it.
Rooting gel is another matter; besides hormones and vitamins, it has the required consistency. The fact that one of the reasons for the failed rooting is the oxidation and dying of the cambium tissue. Gel just protects this tissue from oxidation. This is its main advantage.
In addition, the concentration of stimulators in the gel is very high. All this allows us to increase the number of rooted cuttings by about 20%.
Suppose you have prepared cuttings and soil for rooting. Next, insert the lower tip of the cuttings into the gel; the amount of gel should be sufficient for a longer duration.
Insert the cuttings with the lower tips into the ground to a depth of at least 2 inches. They should be positioned vertically. Slightly squeeze the soil around each branch so that they do not move.
It is not necessary to water the soil immediately. As I wrote above, the substrate should already be slightly moist. Watering can be done in 2-3 days after.
The next thing you need to do is place the cuttings in the greenhouse. If you do not use the greenhouse, rooting will fail. I had an experience of rooting Juniper without a greenhouse, but the number of rooted plants was 1-2%.
So use the greenhouse anyway. If this is not possible, put plastic bags on the containers. They will also provide the necessary humidity, although the packages are not so convenient.
The humidity in the greenhouse should be in the range of 80-100%. The air temperature should be approximately 68 ° F. The greenhouse should also be shaded. You can use a shading grid to do this.
If everything were done correctly, in about a month, young shoots would appear. This is a good sign; however, it does not mean that the cuttings are rooted. Very often, the upper part is still alive, and the bottom is already dead.
The first small roots can appear in 2 weeks. The root system may form within 1-2 months. However, this is not always the case. Rooting can occur throughout the season from spring to autumn. I have had cases where the roots of the cuttings appear next year.
If young growth occurs, spray them with an aqueous solution of fungicide. Ventilate the greenhouse every 2-3 days. If insects have appeared on the plants, spray them with an insecticide or Neem Oil.
If within 3-4 months the cuttings do not dry up, it means that most likely, it has formed a root system. However, do not rush to replant it.
The best thing to do is move it from the greenhouse to open space but into a complete shadow. It can be placed under a dense tree. Water new plants often but not with a large amount of water, the soil should always be slightly moist.
In pots, cuttings can withstand winter. Next spring, you can plant them in separate pots, but again place them in the shade and continuously moisturize. When transplanting, try not to damage the roots.
Later in the late summer or early fall, you can plant new plants, from pots to a permanent place in your garden.
2. Propagating Juniper From Seed
The second common way to propagate Juniper is by seed. It should be said that varietal traits are hardly transmitted by this method.
This type of breeding is trendy among breeders, crossing different varieties they produce very interesting new forms. After a while, the results of their work become available to all of us.
However, there are times when the gardener needs to get many new plants at the lowest cost. This can happen when, for example, you need a lot of ground cover junipers. In this case, you can sow the seeds and get many new plants. The color of the needles is most likely to be green, but the growth pattern is inherited.
It is best to collect seeds in the fall when it is ripe. Then it should be dried. Put the seeds in a dry paper box or bag. Next, place the bag in a dry, dark place indoors without heating. It can be a garage.
The seeds should lie in the box all winter. Check from time to time whether it has become moldy and that it has no insects.
In the early spring, when the sun is already warming enough, you can start sowing. Use clear, peat-based soil for sowing. Rectangular containers of at least 4-5 inches deep are best suited.
Pour soil into containers almost to the top, then sow seeds. The distance between the seeds should be an average of 1 inch. Then sprinkle the seeds with a thin layer of soil.
Lightly pour water. Watering is best done with a sprayer, and it moisturizes the surface more evenly and gently.
Then place the containers in the greenhouse. If there is no greenhouse, you can cover the containers with transparent lids. Containers should be shaded.
The seeds need suitable conditions to sprout. Humidity should be at least 75%. The air temperature should reach 77 ° F.
After 7-10 days, the first shoots will appear. The air and soil around them should be moist but not wet to avoid rot.
Do not transplant seedlings in the first year of sowing. When young plants become strong, they can be gradually exposed to the sun.
Next year, the seedlings can be transplanted into individual pots and shaded. A year later, they can be planted in open ground.
3. Propagating Juniper By Grafting
The third way to propagate Juniper is by grafting. This is a complicated method, and it is used mainly by professionals. By this method, you can propagate rare juniper varieties or create Juniper on the stam.
For grafting, you need to prepare rootstocks. The rootstock should be at least 3-4 years old. Colony-shaped varieties, such as Skyrocket Juniper, are best suited for this. Trunk thickness should be at least 0.5 inches.
The best time for propagating is the end of winter. Cuttings can be harvested earlier, for example, in January. They can be refrigerated until the end of winter.
You need to move well-rooted rootstocks to the greenhouse at the end of December. After two months, you can start graft. You will need a grafting knife and a gum. You should also use wax to treat all wounds.
The internet has a lot of information on how to graft plants. From my experience, I can say that the best results can be obtained by grafting a cambium on cambium.
Clean the lower half of the cuttings from the needles. Do the same on a rootstock for the length of the cuttings. Cut the top layer of bark on the rootstock and the cuttings. The length and width of the cut should be the same in cuttings and rootstocks. Attach cuttings to the rootstock, wound to wound. Wrap with rubber band and fill with wax.
Grafted plants should remain in the greenhouse until August. You can then bring them outside in complete shade. For 2-3 years, cut native branches from the rootstock. As a result, only the grafted part should remain.
4. Propagating Juniper By Layering
The last method of propagation is layering. This method may be the simplest of all, but it is slow enough, rooting can take 1-2 years. Also, this method will not succeed in obtaining a large number of new plants. In addition, only groundcover varieties can be propagated this way.
The idea is that you bend the branches to the ground, and they take root. In the image above, you can see how I root for juniper layering in my garden. Let’s talk about this in more detail.
Layering can be done at any time of year except winter, but the sooner you start, the faster the result.
In the early spring, pick 2-3 branches that you want to root. The thickness of the branches should be approximately 0.5 inches. You need to clean most of the needles and small twigs. Leave the needles only at the end of the branch, as shown in the photo.
Some recommend making cuts at the point where the branch touches the ground. I have never done this, and the branches have taken root. It is bad to make cuts because rot can develop there. The plants have enough force, and the bark itself will crack, and from there, the roots will start to grow.
Next, fasten the branch to the ground with a steel clamp. Try not to damage the branch. It is not necessary to press the branch very hard, just enough that it just touches the ground. You can fill the ground where the branch adjoins the surface.
That’s all, and you don’t need to do anything else. In a year or two, the roots should appear. Pull out the bracket, and if the branch is kept near the ground, it means that it has roots. You can cut it from the main bush. Do not transplant it immediately; let it grow a year in this place.
One year after rooting, you can transplant the plant to a new location. When transplanting, try not to damage the root system.
People also ask
Can I root Juniper cuttings in water?
The probability that the branch of Juniper rooted in the water is very low. Cuttings would rather rot in the water. I have never tried this, but I have heard that some people did. Even if it works, it will be less successful than in clean soil. In addition, you have to constantly change the water because it will deteriorate in a week or two.
How to propagate Juniper ground cover?
Propagation of ground cover juniper is best done by layering. You can even do nothing, and in a few years, some branches that touch the ground will take root themselves.
How to propagate Blue Rug Juniper?
This is a ground cover juniper, so it is best to propagate it by layering or cuttings. Both of these methods have been described in detail in this article. Reproduction of this variety by seeds or grafting is not advisable.
How to propagate Common Juniper?
Common Juniper is very poorly propagated by cuttings and layering. I have never been able to reproduce it by these methods. This species is better propagated by seeds, but the varietal characteristics are not transmitted in this way. The second way is grafting; it is advisable to do for rare varieties, for example, Juniperus communis Gold Cone.