Origin and Common Names
Crataegus flabellata (Spach) Kirchn. var. densiflora (Sarg.) Kruschke is a species of the Crataegus genus, which belongs to the Rosaceae family. This plant is native to Japan and is commonly known as the Japanese hawthorn or tsubaki-hawthorn.
General Appearance
The Japanese hawthorn is a deciduous tree that can grow up to 10 meters in height. It has a broad, rounded crown and a dense, bushy habit. The leaves of this tree are alternately arranged, simple, and ovate with serrated edges. In spring, the tree produces clusters of small, fragrant, white or pink flowers that bloom along the branches. These flowers are followed by small, red, and edible fruits that ripen in autumn. The bark of the tree is gray-brown and smooth on young branches, but rough and fissured on older branches.
Uses
The Japanese hawthorn has a range of uses and is valued for its ornamental and medicinal properties. This tree is often planted in gardens and parks due to its attractive foliage, showy flowers, and colorful fruits. The fruits of the tree are used in traditional Japanese medicine to treat digestive problems, lower cholesterol, and reduce blood pressure. The tree's wood is also used to make furniture, tools, and traditional Japanese musical instruments.
Light Requirements
Crataegus flabellata var. densiflora requires full sun to partial shade for optimal growth. It can tolerate some shade, but flowering and fruiting might be reduced in shaded areas. Therefore, planting in an open location where it can receive at least six hours of full sunlight is ideal.
Temperature Requirements
The ideal temperature for the growth of Crataegus flabellata var. densiflora is between 60°F to 80°F. The plant can tolerate temperature extremes but prefers to avoid temperatures below -10°C. Therefore, planting and growing in USDA zones 4 to 8 is ideal. The plant can withstand hot summers and cold winters as it is highly adaptable.
Soil Requirements
The soils that best suit Crataegus flabellata var. densiflora are fertile, loamy, and well-drained. The soil type can be slightly acidic to neutral with a pH of 5.5 to 7.5. The plant also prefers a slightly moist soil, but it can tolerate drought conditions. Avoid planting in heavy, compact soil as it can result in root rot.
Cultivation Methods
The Crataegus flabellata (Spach) Kirchn. var. densiflora (Sarg.) Kruschke is an outdoor plant that prefers moist, well-drained soil with full sunlight exposure. It is a hardy plant that can withstand frost and drought. The ideal location for planting is on a slightly elevated site with good air circulation to prevent fungal diseases.
Watering Needs
Young plants require frequent watering, especially during the first growing season. Once established, the plant can tolerate dry spells. The soil should be kept moist but not waterlogged to prevent root rot diseases. It is recommended to water early in the day to allow leaves to dry out before night to prevent fungal diseases.
Fertilization
Nitrogen-rich fertilizers should be avoided as they can lead to excessive growth of leaves at the expense of flowers and fruits. A balanced blend of phosphorus, potassium, and micronutrients is preferred. Fertilization can be done once a year in the spring when new growth is emerging.
Pruning
Crataegus flabellata requires minimal pruning, with dead and diseased wood being cleared throughout the year. Light pruning can be done in late winter or early spring before new growth appears. Pruning should be done to maintain a desired shape, promote air circulation, and encourage blooms and fruit production. Avoid heavy pruning, as it can damage the plant.
Propagation of Crataegus flabellata var. densiflora
Propagation is an important process in growing Crataegus flabellata var. densiflora as it allows for the plant to reproduce and expand. There are different methods of propagation, such as from seeds, cuttings, and grafting.
Propagation from Seeds
Propagation from seeds is a common and affordable method of growing Crataegus flabellata var. densiflora. The seeds can be collected from the plant during autumn, and they need to be stratified for three to four months. This means that the seeds have to be exposed to cold and damp conditions to break their dormancy. After stratification, the seeds can be sown in pots or a seedbed during spring. The seedlings can be transplanted after a year when they reach a height of 10 to 15 cm.
Propagation from Cuttings
Propagation from cuttings is another method of growing Crataegus flabellata var. densiflora that is faster than from seeds. The cuttings are taken from the plant during autumn, and they should be 15 to 20 cm long and have several buds. The cuttings need to be treated with rooting hormones, and they can be planted in pots with a soil mix of peat and perlite. The pots should be covered with plastic to create a humid environment for the cuttings. Rooting takes around two to three months, and the rooted cuttings can be transplanted into bigger pots or outside when they reach 10 to 15 cm in height.
Propagation from Grafting
Propagation from grafting is a method used to propagate desirable cultivars of Crataegus flabellata var. densiflora. The scion, which is the desirable cultivar, is grafted onto a rootstock from a different hawthorn species that has better soil adaptation and resistance to pests and diseases. The grafting should be done during early spring, and the grafted plant should be kept in a humid and warm environment until the graft has taken and new growth appears. After the new growth has appeared, the grafted plant can be transplanted in a suitable location.
Disease Management
Common diseases that might affect Crataegus flabellata var. densiflora are fire blight, leaf spot, and powdery mildew. Fire blight is a bacterial disease that affects a wide range of plants and can be identified by the blackening and shriveling of the flowers and stems. Leaf spots are fungal diseases that create small brown or black lesions on the leaves. Powdery mildew is a fungal disease that forms a white powdery coating on the leaves, stems, and flowers.
To manage fire blight, prune and destroy infected branches and avoid overhead watering. Leaf spot can be managed by removing and destroying infected leaves and avoiding overhead watering. Powdery mildew can be managed by improving the air circulation around the plant and treating infected areas with a fungicide.
Pest Management
Common pests that might affect Crataegus flabellata var. densiflora are aphids, scale insects, and spider mites. Aphids are small, soft-bodied insects that pierce the plant to feed on its sap, causing distorted growth and the excretion of honeydew. Scale insects are small, immobile insects that attach themselves to the plant, sucking the sap and causing yellowing and dropping of leaves. Spider mites are tiny insects that spin webs on the plant and feed on its sap, causing discoloration, webbing, and eventual leaf drop.
To manage aphids, introduce natural predators such as ladybugs or lacewings and wash the plant with a strong spray of water to dislodge the insects. Scale insects can be manually removed with a soft brush or treated with an insecticidal soap. Spider mites can be managed by increasing the humidity around the plant and treating with a miticide if the infestation is severe.
