Detailed Guide to the Cutting Propagation Method and Key Points of Araucaria heterophylla
Araucaria heterophylla, also known as Monkey Puzzle, Tower Araucaria, Norfolk Island Pine, etc., is often cultivated as a foliage plant in China. Nowadays many gardening enthusiasts make Araucaria heterophylla into bonsai, which also has relatively high ornamental value. Artificial propagation of Araucaria heterophylla can be done by the cutting method.
Araucaria heterophylla, also known as Monkey Puzzle, Tower Araucaria, Norfolk Island Pine, etc., is often cultivated as a foliage plant in China. Nowadays many gardening enthusiasts make Araucaria heterophylla into bonsai, which also has relatively high ornamental value. Artificial propagation of Araucaria heterophylla can be done by the cutting method. The editor will now introduce the cutting method and precautions for Araucaria heterophylla.
Araucaria heterophylla
I. Construction of the Cutting Bed
The cutting bed is built with bricks, 25m high, 10Ocm wide, with the length determined by the number of cuttings. The bed bottom should be level, and the cutting substrate is placed inside the bed, slightly leveled and compacted before use.
II. Selection of the Cutting Environment
The selection of the cutting environment is very important for cutting survival. The suitable rooting temperature for Araucaria heterophylla is 15-25 degrees, the humidity is 70%-80%, and there should be sufficient light, with light shading being preferable. Choosing a cutting site set up under such moist conditions for cutting propagation makes it easy to form adventitious roots and adventitious buds, resulting in a high survival rate.
III. Cutting Method
For root cuttings, row planting is preferable, with a plant spacing of 4cm and a row spacing of 6cm being suitable. Use a strip of board 6cm wide, 1OOcm long and 2cm thick as a ruler, placed on the sand bed to mark the row spacing. Use a small shovel to open diagonal trenches along the edge of the board, with a depth of about 7cm. The cuttings should be inserted into the sand bed to about 2/3 of their length, then placed neatly in the trench at equal distances of about 4cm, making sure the heads face upward, then cover with sand and compact. After planting, water thoroughly once.
Key Points for Seed Sowing and Cutting Propagation of Araucaria cunninghamii
Araucaria cunninghamii (see detailed introduction) is an evergreen tree of the family Araucariaceae. Its leaves are deep green, and the whole plant is graceful and dignified. Nowadays many gardening enthusiasts make Araucaria cunninghamii into bonsai to decorate venues and halls. So how should Araucaria cunninghamii be propagated?
Araucaria cunninghamii (see detailed introduction)
I. Sowing
Araucaria cunninghamii can be propagated by sowing or cutting. Araucaria cunninghamii planted in the north rarely sets seed, so cutting propagation is often used. In spring, collect the upright new shoots or vigorous growing branches sprouting from lateral buds as cuttings (if lateral branches or weak branches are used as cuttings, the crown shape of the cultivated plant will be irregular and lose its ornamental value). The cuttings are 7cm long, and can root when inserted into a greenhouse sand bed at a temperature of 13-16°C and an air relative humidity of 60-80%. Alternatively, truncate the top of a young tree, wait for the lateral buds at the top to sprout upright new shoots, and then cut the branches for cuttings in spring.
II. Cutting
Before sowing, it is best to break the seed coat first to promote germination. Seed-sown seedlings have long taproots and few fibrous roots, and are prone to dying when transplanted. Mastering technical points such as root protection, careful planting, heat preservation and shading can improve the survival rate of seedlings. For seedlings with broken roots, wash them with clean water and insert them into plain sand; at a suitable temperature, they will re-root from the cut surface in 1-2 weeks. For seedlings with broken buds or stems but retaining leaves, they can be planted as usual, and after surviving they will sprout new buds after a certain period.
Araucaria cunninghamii Araucaria cunninghamii Illustrated Guide: How to grow Araucaria cunninghamii / How to propagate Araucaria cunninghamii
Araucaria cunninghamii ProfileAraucaria cunninghamii Araucaria cunninghamii
Cultivation Methods and Precautions of Araucaria cunninghamii Introduction to Araucaria cunninghamii
Araucaria cunninghamii is an evergreen tree native to Norfolk Island, Australia. It has many names: according to its place of origin, it is called English Pine, Australian Pine, Norfolk Island Pine, and Nanyangshan. According to leaf type, it is called Araucaria heterophylla, Small-leaved Araucaria, and Beautiful Araucaria. According to form, it is called Tower Araucaria, Hainan Araucaria, etc. Varieties introduced to China include Araucaria cunninghamii and Norfolk Island Pine. Araucaria cunninghamii has an upright trunk, and the whole tree is tower-shaped, with branches whorled and extending horizontally, with uniform whorl spacing and distinct layers, no thorns, and a dignified appearance. It is a top-grade foliage plant, mostly grown in pots. Norfolk Island Pine is an excellent ornamental garden plant, and when planted in the ground it can reach a height of more than 30m. It likes warmth and sunlight, can tolerate high temperatures of 40°C, and can also withstand low temperatures of minus 5°C. It can survive outdoors around the 27°C latitude line (Norfolk Island is located at 27°C south latitude).
Morphological Characteristics of Araucaria cunninghamii
Tree, in its place of origin up to 60-70m tall, DBH over 1m, bark grayish brown or dark gray, coarse, with horizontal fissures; Araucaria cunninghamii (ink line drawing) large branches flat or obliquely extending, young tree crown pointed tower-shaped, becoming flat-topped when old, lateral branchlets densely growing, drooping, nearly pinnately arranged. Leaves dimorphic: leaves on young trees and lateral branches loosely arranged, spreading, cone-shaped, needle-shaped, sickle-shaped or triangular, 7-17mm long, about 2.5mm wide at the base, slightly curved, slightly four-angled or with inconspicuous ridges on the upper (ventral) surface, with many stomatal lines on the upper surface, stomatal lines on the lower surface irregular or nearly absent, gradually narrowing toward the upper part, apex with a tapering or slightly acute tip; leaves on large branches and flower and fruit branches densely arranged and overlapping, extending obliquely upward, slightly curved upward, ovate, triangular-ovate or triangular, without obvious dorsal ridge or with a longitudinal ridge on the lower surface, 6-10mm long. Cones ovate or elliptical, 6-10cm long, about 4cm wide, broad at the base, gradually narrowing or slightly rounded at the upper part, apex acute or obtuse, midrib obvious or not obvious, grayish green on the upper surface with white powder and many stomatal lines, green on the lower surface with only irregular sparse stomatal lines in the middle and lower part. Male cones solitary at the branch tips, cylindrical. Cones ovate or elliptical, 6-10cm long, 4.5-7.5cm in diameter; bract scales cuneate-obovate, with thin wings on both sides, broad and thick at the apex, with a sharp ridge, with an acute long tail-like tip in the center, the tip obviously recurved backward; the apex of the seed scale is thin, not fleshy; seeds elliptical, with membranous wings on both sides formed by fusion.
Ecological Habits of Araucaria cunninghamii
It likes a warm climate, fresh and moist air, and soft and sufficient light. It is not cold-tolerant and avoids drought. In winter it needs sufficient sunlight, and in summer it should avoid strong direct sunlight. It fears the dry fierce winds of northern springs and the scorching sun of midsummer. It grows best under environmental conditions of 25°C-30°C and relative humidity above 70%. For pot cultivation, it requires loose, fertile culture soil with high humus content and strong drainage and aeration.
Cultivation Techniques of Araucaria cunninghamii Selection of Root Cutting Mother Plants
The root cutting mother plant is the propagation parent that provides high-quality planting material, and must be strictly selected to ensure the retention of the excellent characteristics of the mother plant. Generally, trees 5-10 years old suitable for use as landscaping seedlings are used, specifically robust plants free of pests and diseases, with deep green leaves, tightly arranged whorled branches, and good performance traits.
Collection of Root Cuttings
April-May each year is a good period for landscaping and also the best time for cutting propagation. A large number of landscaping seedlings leave the nursery, and this opportunity can be used to collect the remaining root systems after seedlings are dug up. Parts of the root system of Araucaria heterophylla trees in shallower positions below the soil surface can also be dug up. These serve as materials for cutting propagation.
Treatment of Root Cuttings
The treatment of root cuttings in vegetative propagation is an important step related to the survival and rooting of cuttings. Araucaria heterophylla root cuttings should be treated promptly. The method is: select roots with a cross-section of 0.8-1.2Cm, cut them to about 10cm, arrange them in order from head to tail, bundle 20-30 roots as one bundle, and place them in a cool, ventilated place to promote evaporation of excess water from the fleshy roots to prevent rot. The drying time is generally about one week. Selection of Cutting Substrate and Environment Selection of Cutting Substrate: Choose sieved pure river sand with a particle size of 0.5-1.Omm as the cutting substrate, which has the advantages of good aeration and drainage.
Construction of the Cutting Bed
The cutting bed is built with bricks, 25m high, 10Ocm wide, with the length determined by the number of cuttings. The bed bottom should be level, and the cutting substrate is placed inside the bed, slightly leveled and compacted before use.
Selection of the Cutting Environment
The selection of the cutting environment is very important for cutting survival. The suitable rooting temperature for Araucaria heterophylla is 15-25 degrees, the humidity is 70%-80%, and there should be sufficient light, with light shading being preferable. Choosing a cutting site set up under such moist conditions for cutting propagation makes it easy to form adventitious roots and adventitious buds, resulting in a high survival rate.
Cutting Method For root cuttings, row planting is preferable, with a plant spacing of 4cm and a row spacing of 6cm being suitable. Use a strip of board 6cm wide, 1OOcm long and 2cm thick as a ruler, placed on the sand bed to mark the row spacing. Use a small shovel to open diagonal trenches along the edge of the board, with a depth of about 7cm. The cuttings should be inserted into the sand bed to about 2/3 of their length, then placed neatly in the trench at equal distances of about 4cm, making sure the heads face upward, then cover with sand and compact. After planting, water thoroughly once.
Seedling Transplanting
Araucaria cunninghamii likes warmth and moisture, is shade-tolerant, and not cold-tolerant. Seed-sown seedlings have long taproots and few fibrous roots. When transplanting seedlings, they are prone to dying. To improve the survival rate of Araucaria cunninghamii seedling transplanting, the following technical points should be mastered. I.Root Protection
Because Araucaria cunninghamii seedlings have few lateral roots and fine fibrous roots, they will wither and dry out if not given attention, so protecting the seedling root system is very important. First, they should be transported with the pot and soil, and the original culture soil should be kept moist. Second, after the seedlings are purchased, they should be planted immediately. If planting cannot be done in time, they should be placed in a cool, moist place and not exposed to the sun, in order to protect the seedlings, especially the root system, and keep them fresh. In addition, when the winter temperature is low, the root system is susceptible to freezing during transport, so attention should be paid to heat preservation.
II.Careful Planting
When planting, the seedlings should retain as much original soil as possible. The planting soil should be loose and fine, and too much force should not be used to press the soil at the root. After planting, water thoroughly to settle the roots. In addition, seed-sown Araucaria cunninghamii seedlings have long taproots, so planting should be deeper to prevent root exposure and lodging, which would affect survival.
III.Heat Preservation
Araucaria cunninghamii is not cold-tolerant. If seedlings are purchased and planted in winter or early spring, in addition to paying attention to freeze protection during transport, heat preservation measures should also be taken after planting, such as planting in a greenhouse or covering with an arched plastic film.
IV.Shading
Araucaria cunninghamii is a shade-tolerant flowering plant, and seedlings are even more afraid of exposure to the sun, so shading should be provided immediately after planting.
V.Treatment of Broken and Damaged Seedlings
Araucaria cunninghamii seedlings have tender tissues and are easily broken and damaged. The following methods can be used for remediation. For seedlings with broken roots, wash them with clean water and insert them into plain sand; at a suitable temperature, they will re-root from the cut surface after 1-2 weeks, and can be planted after the root system is well developed. For seedlings with broken buds or stems but retaining leaves, they can be planted as usual, and after surviving they will sprout new buds after a certain period.
Bonsai Making
The process of making Araucaria cunninghamii bonsai is not complicated. Its growth habits are: it likes light, a humid climate and acidic fertile soil. Before potting, first prepare the culture soil, then according to the size of the plant, choose a purple clay oval ceramic pot. In terms of material selection, seedlings grown from seed are preferable. Generally, seedlings about fifty centimeters are used; those with thick and robust growth, short internodes and deep green color are considered top grade.
When starting to pot, first remove the plant from the clay pot, peel away an appropriate amount of soil from the bottom upward, being careful not to damage the absorbing roots. Then cover the bottom of the pot with culture soil 1-2cm thick, determine the viewing side, place the tree blank at one end of the pot, straighten the plant, then add culture soil, gently firm it, and then shape the upper part. Shaping the upper part of Araucaria cunninghamii is relatively difficult; from bottom to top, each layer of branch pads has four to five whorled branches. First cut off the lowest layer of whorled branches, then cut off the upper and lower horizontal branches on the left side of the tree, then cut off one branch each at the front and back, then slightly bend and pull individual upper branch pads so that the branch supports appear natural and orderly. Because the base of the main trunk of Araucaria cunninghamii seedlings is roughly the same thickness, use prepared palm fiber sheets to wrap the main trunk into a tree body that is thick at the bottom and thin at the top, then gently tie it with fine rope twisted from palm silk, not too tightly. In this way, the base of the main trunk has a proper variation in thickness, forming a large-tree-shaped crown. If there are no protruding tree roots at the base root plate, several purplish-brown curved tree roots should be appropriately added to protrude above the soil surface to show stability, thus solving the shortcoming of bonsai trees that have no roots as cuttings. Finally, add a small brownish-yellow elephant stone, which gives a rather southern scenery charm. In this way, a lush, beautiful and elegant Araucaria cunninghamii bonsai is presented before your eyes.
After completing the above work, water thoroughly to settle the roots and place in a shaded place for half a month for maintenance, after which it can be transferred to routine management. To promote vigorous growth, in summer and autumn spray the leaves once a month with a mixed solution of 0.3 percent potassium dihydrogen phosphate and urea, thereby maintaining the deep green leaf color.
Pot Cultivation Management Loosening Soil and Watering
After planting, water in time and loosen the surface soil to reduce water evaporation. Usually watering should be moderate. During the growing season, water frequently, 2-3 times a week, with penetration of 10-15cm being suitable. As the seedlings grow, reduce the number of waterings, and regularly keep the pot soil and surrounding environment moist, strictly preventing drought and waterlogging. In hot and dry periods, water or mist the leaves and surrounding environment frequently to increase air humidity and keep the soil moist. Avoid the pot soil being too dry in summer or the water amount being too large in winter; both too dry and too wet can easily cause the lower leaves to droop and soften. In summer, avoid strong direct sunlight; it can be placed in a shaded place under a shed, and water should be sprinkled frequently to maintain relatively high air humidity.
Shaping Management
Araucaria cunninghamii is valued for its upright and straight plant posture. In the second year of cutting seedlings, or when seed-sown seedlings grow to about 50cm, a stick should be set up and wrapped for support to prevent the plant from twisting and affecting the ornamental effect. Young trees should be repotted once every year or every other year in spring. Plants over five years old should have their pots and soil changed once every two or three years, combined with spraying chlormequat to control the height of Araucaria cunninghamii. In northern regions, move them outdoors at the end of April or early May and place them in a wind-protected, sunny place for maintenance. In midsummer, appropriate shading is needed. During the growing season, rotate the pot in a timely manner to prevent skewed tree growth that would affect ornamental value. Araucaria cunninghamii is not tolerant of severe cold. In northern regions, move it indoors at the end of September or early October (Cold Dew), place it in a place with sufficient sunlight and air circulation, stop fertilizing and control watering, and the room temperature must not be lower than 8°C.
Frequent Fertilization
For potted Araucaria cunninghamii, it is suitable to use a mixture of leaf mold, peat soil, pure river sand and a small amount of decomposed organic fertilizer. The pot soil is preferably mixed with 3 parts loam, 1 part leaf mold, 1 part coarse sand and a small amount of plant ash, with the depth of the soil layer controlled so that the bud points rooting in the upper layer are just exposed on the soil surface. Starting from the sprouting of new buds in spring, apply 1-2 times a month of decomposed dilute organic liquid fertilizer and calcium fertilizer, which can keep the plant posture fresh and the leaf color glossy.
Monthly Management
January: Do a good job of cold protection for overwintering. Room temperature should be above 10°C. Control watering, stop fertilizing, and provide sufficient light.
February: Same management as the previous month.
March: As the weather warms, appropriately increase watering and fertilizing, and do a good job of indoor ventilation. Usually pay attention to protecting the lateral branches so as not to damage them and affect the plant shape. Under normal conditions, Araucaria cunninghamii does not need pruning or shaping; it is best to let it grow naturally.
April: Repot once every 2-3 years. The pot soil can be made from peat soil and leaf mold plus about 1/4 river sand and a small amount of base fertilizer.
May: It can be moved outdoors, with 50%-70% of sunlight shaded. During the growing period, in addition to watering, water should also be sprayed on the leaves and ground to lower the ground temperature and increase air humidity. During the growing period, topdressing should be applied 1-2 times a month. To keep a good plant shape, attention should be paid to frequently rotating the pot position so that light is received evenly and the plant shape remains straight.
June: For cutting propagation, terminal buds must be used, not lateral branches, because seedlings propagated from lateral branches cannot grow upright and can only grow horizontally. Cuttings are about 15cm long and are inserted into a cutting bed made of coarse sand or vermiculite, with about 1/3-1/2 of the cutting inserted into the bed. Maintain 20-25°C and relatively high air humidity, and they can root in 4-6 months.
July: Same management as the previous month.
August: Same management as the previous month.
September: As the weather turns cool, control watering and fertilizing, and provide sufficient light. To prevent the plant from growing crooked, insert a thin bamboo pole beside the seedling for support to ensure a proper and beautiful plant shape.
October: Move indoors, control watering, stop fertilizing, and increase light. To prevent an uneven crown, rotate the pot once every half month.
November: Do a good job of heat preservation in winter. Keep the soil moist. Rotate the pot once every half month.
December: Same management as the previous month.
Disease Control of Araucaria cunninghamii Anthracnose
[Symptoms]: The disease occurs on leaves. Small brown spots first appear on the leaves, then expand and spread, causing local branches and leaves to turn brown and die.
[Pathogen]: Colletotrichum derridis
[Control Methods]: 1. Clean the garden and promptly remove diseased residues, carry them out of the field and burn or bury them deeply.
2. In the early stage of the disease, spray 50% carbendazim wettable powder 700 times solution or 40% sulfur suspension 600 times solution, once every 7-10 days, for 3-4 consecutive treatments.
Leaf Blight
[Symptoms]: Part or all of the affected small needles turn grayish brown to grayish white and dry up, with dense small black grains on them.
[Pathogen and Disease Characteristics]: The pathogen is a fungus of the subphylum Deuteromycotina, mainly Macrophoma sp., and also Phyllosticta sp. and Diplodia sp. The pathogens all survive the winter as mycelium and conidiomata in diseased leaves and diseased residues. Conidia are produced and spread by wind and rain to cause infection. It occurs more in warm and rainy years and seasons.
[Control Methods]: Refer to the control of Podocarpus leaf blight. You can also spray 40% sulfur-carbendazim suspension 600 times solution, or 30% copper oxychloride suspension 600 times solution, or 25% myclobutanil emulsifiable concentrate 8000 times solution, or 40% flusilazole emulsifiable concentrate 8000 times solution, or 50% hymexazol aqueous solution 1500 times solution, or 69% metalaxyl-mancozeb + 75% chlorothalonil wettable powder 1500 times solution, or 65% duokebeng wettable powder 600 times solution. In gardens where the disease frequently occurs, spray once in winter and spring combined with garden cleaning, combining ground spraying and tree spraying for better results.
Scale Insects
Can be controlled with 40% omethoate 1000-1500 times solution.
Yellowing Leaves
The causes of yellow leaves in Araucaria cunninghamii can be summarized as the following 5 points:
1. Too weak light. When maintained in a well-lit place, Araucaria cunninghamii grows well. If kept in a place with relatively low light for a long time, it will show leaf yellowing accompanied by leaf drop. It needs to be moved to a place with better light in time, otherwise the plant will worsen further.
2. Overwatering. The watering principle for Araucaria cunninghamii is to water when dry and not when wet. Never water too much or too frequently. Do not water if the pot soil is not dry, otherwise the root system will lack oxygen and rot, making it difficult to absorb water and nutrients, and the plant will show symptoms of discomfort. [3] 3. Damage from low or high temperatures. When the temperature is below 5 degrees, Araucaria cunninghamii will develop yellow leaves and a small amount of leaf drop. During high-temperature periods, if the air humidity is low, a large number of yellow leaves will appear.
4. Air humidity that is too low or wind that is too strong causes acute dehydration and yellowing of leaves. This requires placing it in a wind-protected place, or frequently spraying or sprinkling water to increase air humidity.
5. Infection by diseases. Generally, carbendazim, chlorothalonil and other drugs should be sprayed for prevention.
Propagation Methods of Araucaria cunninghamii Sowing Propagation
Because the seed coat is hard and the germination rate is low, it is best to break the seed coat before sowing to promote germination. In addition, sown seedlings are susceptible to pests and diseases, so the soil used should be strictly sterilized. The seeds are best germinated in a sand bed or by the above-mentioned shell-breakingsowing method to increase the seed germination rate. Generally, they can germinate in about 30 days. Cutting Propagation
Cutting propagation is relatively easy and widely used. Cuttings are generally carried out in spring and summer, but the main branch must be selected as the cutting; plants grown from lateral branch cuttings are crooked and not upright. The cuttings are 10 to 15cm long. After insertion, under conditions of 18°C to 25°C and relatively high air humidity, they can root in about 4 months. If the base of the cutting is soaked in 200 ppm indolebutyric acid (IBA) for 5 hours before cutting, rooting can be promoted earlier.
To obtain more main branches as cuttings, the young tree can be truncated to make the top sprout many upright new shoots, which are cut in spring as cuttings. This truncated mother plant can still continue to grow terminal buds afterward and be used as a permanent propagation mother plant. For potted Araucaria cunninghamii soil, it is suitable to use a mixture of 40% peat soil, 40% leaf mold and 20% river sand. During the growing period, the pot soil should be kept moist; when too dry, the lower leaves will droop and soften, but in winter a slightly dry state should be maintained. In winter, the room temperature should be kept above 5%, as low temperatures will freeze and kill the growing points.
Renewing Plants by Air Layering
If conditions in the shed or greenhouse permit, after girdling at an appropriate height on the plant, plant the whole plant in the ground with the cut buried at a depth of more than 10cm. After about 1-2 years, when the plant has rejuvenated and new roots have grown sufficiently, lift the plant and pot it. At this time, the original old roots have decayed and can be removed. The new plant is shorter and sturdier and more ornamental.
Distribution Area of Araucaria cunninghamii
Native to the southeastern coastal areas of Oceania. In China, it is cultivated in Guangzhou, Hainan Island, Xiamen and other places as a garden tree, growing quickly. Araucaria cunninghamii - trunk, has already flowered and fruited; north of the Yangtze River it is grown in pots.
Australia and New Guinea, and in China in Guangzhou, Hainan Island, Xiamen and other places
Variety Classification of Araucaria cunninghamii
Araucaria bidwillii Hook.
Araucaria heterophylla (Salisb.) Franco
Uses and Functions of Araucaria cunninghamii Ornamental Value
Araucaria cunninghamii has a tall tree form and graceful posture. It, together with cedar, Japanese golden larch, North American redwood and golden larch, is called one of the world's 5 great park tree species. It is most suitable for solitary planting as a landscape tree or memorial tree, and can also be used as a street tree. However, it is advisable to choose a site without strong winds to avoid crown skewing. Araucaria cunninghamii is also a precious indoor potted decorative tree species. Araucaria cunninghamii is a beautiful landscape tree and can be planted alone, in rows, or mixed in tree clusters. It can also serve as a background tree for large sculptures or landscape buildings. Araucaria cunninghamii is also a precious indoor potted decorative tree species, used to decorate hall environments, appearing very elegant.
Araucaria cunninghamii has a pointed tower-shaped tree form with luxuriant branches and leaves, and leaves that are triangular or ovate. It is one of the world-famous garden trees; it can be planted in rows, alone, or mixed in tree clusters, and can also serve as a background tree for sculptures or landscape buildings. It can also be used as a street tree, but it is advisable to choose a site without strong winds to avoid crown skewing. Potted seedlings are suitable for decorating the living room, corridor and study of ordinary families; they can also be used to arrange various forms of venues and exhibition halls; they can also be used as gifts for relatives and friends on the joy of opening a business or moving house.
Timber Value
Araucaria cunninghamii has excellent wood quality and is an important timber tree species in Australia and South Africa. It can be used for construction, utensils, furniture, etc.
Araucaria cunninghamii Pictures