Chinese juniper(Juniperus chinensis) is a coniferous tree or shrub popular in garden plantings. Low requirements, resistance to diseases and a we alth of forms and colors make it an ideal plant for almost any garden. Meet the most interestingvarieties of Chinese juniperand find out what it looks likegrowing juniper in the gardenWe also advise how to prune these shrubs, how to fightjuniper diseases Chinese , as well as what are theways to breed juniperson your own.
Chinese juniper - Juniperus chinensis
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What does Chinese juniper look like?
Chinese juniper(Juniperus chinensis), native to China, Japan and Mongolia, belongs to the cypress family (Cupressaceae). In our country, in its natural state, the only representative of this family is juniper. Chinese juniper reaches 25 m in height, but breeders target the groupof Chinese juniper varieties much shorter , among which we can find many small dwarf shrubs.
Chinese juniper has aquite regular, compact crown with a conical or columnar shape, although you can also buycreeping varieties of Chinese juniperW in gardens it reaches a height of several dozen cm to even 10-15 m, depending on the variety planted.
Chinese juniper shootsin the initial stage of growth are covered with green needles, which over time they transform into scales adhering to the shoots. Some varieties of Chinese juniper have both needles and scalesAt the ends of the shoots appear not too impressive inflorescences, which give rise to blue cones-berries ripening in the second year after flowering. Plants give off a characteristic, pleasant, pungent smell.
Chinese juniper 'Old Gold'
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Chinese juniper - application
Flowing varieties of Chinese juniperare perfect as ground cover plants, covering slopes, slopes and areas under higher plantings of trees and shrubs.Chinese juniper column varietiescan be used to create alleys, lanes or labyrinths. Dwarf varieties are perfect for rock gardens or grown in containers.
Junipers can createbeautiful, mixed flower beds in the company of shrubs such as barberry, azalea, tawula and Fortune's euonymus.Under junipers, we can also plant bulbs, such as tulips, sapphires and crocuses. Due to its high resistance to pruning, theChinese juniper is often usedby bonsai lovers and formed into small trees.
Chinese juniper bonsai tree
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Chinese juniper - varieties
Like other junipers, alsoChinese junipers come in a variety of shapes and sizes.Trees up to 15 m tall as well as dwarf and even creeping shrubs are available for sale. The color palette of Chinese juniper varieties is also wide, from lush green through silvery to golden and cream. Everyone will find something for himself.Among the huge number of varieties of Chinese juniper , we have selected a few of the most popular and best-suited for Polish gardens.
Chinese juniper 'Variegata'- a variety with a conical shape.It grows slowly and reaches 2-3 m in height. The highly compacted crown is characterized by mixed foliage - there are both scales and stiff, blue needles. An additional attraction are twigs with white needles, which cover the plant irregularly and form white spots.
Chinese juniper 'Expansa Variegata'- creeping variety only 30 cm high. Attractively colored (green-blue foliage with cream spots) it works great as a turf plant.
Chinese juniper 'Stricta Variegata'
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Chinese Juniper 'Obelisk'- is a fast growing variety with a compact, columnar shape. The bluish needles are very long, stiff and prickly, slightly bent. Plants grow up to 3-4 m in height. The variety does not set seeds. Due to its speed of growth and columnar habit, the 'Obelisk' juniper is a great alternative to thuja when creating hedges.
Chinese juniper 'Spartan'- is one of the most popular varieties of Chinese juniper, fast-growing, reaching up to 3 m in height after 10 years. It creates a beautiful column with a dark green color and decorative blue fruits. An excellent variety both for a hedge and for single plantings as a solitaire. Juniper 'Spartan' has minimal cultivation requirements and is fully hardy.
Chinese juniper 'Stricta'- is a slow growing, dwarf variety, after 10 years of cultivation the shrubs reach about 2 meters in height. The branches are covered only with soft, bluish needles. The variety is versatile, it looks good in the garden, as a solitary plant, or as an element of mixed beds. It can also be planted in containers.
Chinese juniper 'Stricta'
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Chinese Juniper 'Blaauw'- is a slowly growing shrub with an inverted cone-shaped crown. This dwarf variety reaches 1.5 m in height after 10 years of cultivation. Thin shoots are covered with blue-gray, flush scales.
Chinese juniper 'Aurea'- is one of the most beautiful golden juniper varieties. The needles growing on thin branches turn bright and golden yellow shades, beautifully looking, at any time of the year. The variety requires a position sheltered from both cold winds and direct sunlight.
Chinese juniper - planting and cultivation
Chinese juniper has low cultivation requirements . It is enough to provide it with a dry, sunny position with sandy loam soil and the pH of the soil will be slightly acid to neutral (pH 5.5-7.0). Yellow-colored varieties grow best in semi-shaded positions.
Chinese juniper seedlingssold in pots can be planted all year round, whenever weather conditions allow it. When preparing the position for the cultivation of Chinese juniper, remove the weeds, loosen the soil and mix it with fertilizers.
Then we dig an appropriate sizehole for each juniper seedling(it should be 2 times wider and deeper than the root ball of the seedling).Before backfilling, the soil selected from the holes should be mixed with peat or compost in order to fertilize it. Too compact soil can be mixed with sand to loosen its structure. Then we pour some of the prepared soil on the bottom of the hole and place the plant at the depth it grew in the container. After backfilling the hole, lightly knead the soil and water it abundantly.
It is advisable to mulch the soil around thenewly planted Chinese juniperPine bark is a good bedding material. The mulch will prevent weeds from growing and water from evaporating from the soil.
Watering Chinese juniperdoes not have to be frequent, as junipers growing in the ground are resistant to short-term drought. We water them only in the case of a prolonged lack of rainfall. We water the plants for a longer period - also in autumn, in snow-free winters and in early spring, if the rainfall or snowfall is insufficient. During this period (especially during snowless winters), plants are threatened with the so-calledphysiological drought.Junipers growing in potsshould be watered more often as soon as the soil becomes dry.
Chinese juniper 'Kaizuka'
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The firstfertilization of the Chinese juniper is donebefore planting, mixing the soil with compost, manure or peat. During the growing season, it is also worth using mineral fertilizers that will ensure faster growth and better color of the needles. The best solution is to use multi-component fertilizers containing a complete set of macro - and microelements necessary for the growth. You can use a product with versatile use (e.g. Osmocote universal fertilizer) or a specialist fertilizer for conifers.
Chinese juniper is resistant to the most severe frosts(most popular varieties belong to the 5A plant frost resistance zone). It does not need to be secured for the winter. Some variations, such asChinese juniper 'Stricta' and Chinese juniper 'Variegata' have a slightly weaker frost resistance (frost resistance zone 6A), but they also cope with the Polish climate without any problems. Only plants grown in containers should be protected against the freezing of the root ball, e.g. by placing the pot in a larger container and filling the free space with insulating material (polystyrene, sawdust or cut newspapers).
Chinese juniper 'Torulosa Variegata'
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Chinese juniper - pruning
Chinese juniper tolerates pruning well , thanks to which we can freely form the plant and regulate its growth. Older specimens that no longer show such regenerative abilities, try to cut more gently or stop pruning at all.
Pruning Chinese juniper is performed on two dates:
- we make the first cut in spring, before new growths appear,
- the second cutting date for Chinese juniper is summer, from mid-July to mid-August.
Later we do not cut so as not to expose the plant to frost. Newly trimmed shoots must regenerate before winter comes.
Chinese juniper hedgescan be freely shaped with a hedge trimmer. With freely growing shrubs, in planting in flowerbeds, proceed a bit differently.
First of alluse a secateurs for cutting juniper bushes, which will allow for precise pruning of twigs in selected places. We select single branches that are cut as close to the middle of the bush as possible.If we only want to slightly shorten selected twigs , shorten them with secateurs in the corners from which smaller side branches grow. They will cover the cut places and the bush will retain its natural appearance.
How to become confident in pruning plants?
If you are unsure how to cut or simply afraid to do it, the fantastic book "Cutting School" will help you. Thanks to it, you will gain confidence in pruning plants and learn to cut plants so that they grow according to your expectations. After reading this book, your approach to pruning plants will probably change completely!
Chinese juniper can be multiplied in two ways:
Chinese juniper propagation from seeds- juniper seeds should be stratified at -4 ° C in a moist medium for 6-18 months. When the seeds start to germinate, we sow them into pots filled with a permeable substrate, e.g. a mixture of peat and sand with a pH of approx. 5.0-5.5. Cover the seeds with a thin layer of sand and cover them with foil or glass.
Chinese juniper seedlingsobtained from seedsmust be aired frequently to prevent fungal diseases.In the third year after sowing, the seedlings can be planted permanently. Remember, however, that the seeds of ornamental varieties often do not repeat the characteristics of the mother plant.Garden varieties of Chinese junipersit is much better to propagate vegetatively through cuttings.
Chinese juniper seedlings
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Chinese juniper propagation by cuttings
- the best time to pick Chinese juniper cuttings is autumn (September-November). We prepare the seedling by taking a fragment of the shoot along with the heel. We remove the needles from the bottom of the seedling and shorten its top so that it is 10-15 cm long. Dip the lower part in the rooting agent (optional), then plant it in a permeable substrate and water it.Duringrooting Chinese juniper cuttingsthe temperature of the substrate should be 16 ° C and the air temperature - 12 -15 ° C. We cover the boxes with seedlings with glass or foil, often airing them.In May, already rooted plants can be transplanted into pots and replaced permanently after 1-2 years.
Chinese juniper - diseases and pests
The Chinese juniper is a resistant species . Nevertheless, plants can be attacked by pathogens from time to time, especially if we do not provide them with proper growing conditions. Below we list the most commondiseases and pests of Chinese junipers .
Phytophthora- is a fungal disease of Chinese juniper and many other trees and shrubs, sometimes also called root rot and root rot. As a result of infection, the plant loses needles and its growth is inhibited. Usually at the base of the shoot, just above the ground, you can see necrotic changes on the shoot. However, phytophthora attacks primarily the roots of the plant, and the effect of this is the changes observed on the above-ground parts. The reason may be too heavy soil and too dense planting. High temperature also contributes to the development of the disease.The firstsymptoms of phytophthora on juniperare best treated with the natural biological preparation Polyversum WP, which the plant is sprayed and watered with. If this is not enough, and the condition of the juniper does not improve, chemical fungicides such as Scorpion 325 SC, Proplant 722 SL, Magnicur Energy 840 SL will help.
Juniper rash- is a fungal disease leading to discoloration and then dropping of the needles. In case of disease symptoms, fallen needles should be collected and burned. Spraying with Scorpion 325 SC and Topsin M 500 SC fungicides is also necessary. In order to limit the use of chemicals, it is worth using them alternately with the natural preparation Biosept Active.
Gray mold- attacks juniper shoots, causing them to die. Disease can be prevented by providing conifers with more space, which will ensure good air circulation and prevent fungus development in a humid environment with high ambient temperature. However, if gray mold occurs on our plants, they can be treated with the biological spray Polyversum WP or Topsin M 500 SC.
We have already listed the most commondiseases of Chinese juniper . Now it's time for pests.
Aphids- these are small bugs that weaken plants, often transmitting viral diseases and promoting fungal infections. There may be specific species of aphids on juniper -miodownice juniperandlicinek juniperAs a result of feeding these pests, juniper needles deform and bend, needles cover and shoots with white waxy secretion produced by aphids and a general reduction in plant growth.As a preventive measure, it is worth spraying with oil preparations Emulpar 940 EC or Promanal 60 EC in early spring. After noticing the symptoms of pest feeding during the growing season, you can also use the natural Emulpar 940 EC, and if that is not enough, use Karate Gold, Mospilan 20 SP or Polysect 005 SL insecticides.
Juniper shield- is another Chinese juniper pest that causes deformation and browning of juniper shoots, and consequently their dieback. After observing the feeding of the pest, spray the plants with the natural oil preparation Emulpar 940 EC.
MSc Eng. Anna Błaszczak
