Origin
Polygonum ×bohemicum, also known as Bohemian knotweed, is a hybrid plant that belongs to the family Polygonaceae. It is a cross between Japanese knotweed (P. cuspidatum) and Giant knotweed (P. sachalinense). It is native to Asia but has become naturalized throughout Europe, North America, and other regions of the world.
Common Names
Bohemian knotweed is also commonly known as Atlantic knotweed, hybrid knotweed, and Bohemian bamboo. In German, it is referred to as Bohemian Knöterich.
Uses
Bohemian knotweed is considered an invasive species in many parts of the world, including Europe and North America. As such, it has limited value in terms of traditional medicinal or culinary uses. However, some research has suggested that the plant may have potential as a biofuel feedstock due to its high cellulose content.
General Appearance
Bohemian knotweed is a perennial plant that can grow up to 10 feet tall. It has hollow stems that are covered in a reddish-brown sheath and bear long, lance-like leaves. The leaves are arranged alternately along the stem and can be up to 8 inches long. The flowers are small and inconspicuous, and are borne on upright panicles in late summer or early fall.
Growth Conditions for Polygonum ×bohemicum (J. Chrtek & Chrtkovß) Zika & Jacobson
Polygonum ×bohemicum (J. Chrtek & Chrtkovß) Zika & Jacobson, commonly known as Bohemian knotweed, is a perennial herbaceous plant. It is a cross between two other species of knotweed -Polygonum polystachyum and Polygonum persicaria.
Light
Bohemian knotweed grows best in full sun but can also tolerate partial shade. Ideally, it should receive at least six hours of direct sunlight daily.
Temperature
Bohemian knotweed can thrive in a range of temperatures. It can withstand frost and temperatures as low as -20°C (-4°F). However, it grows best in areas with a temperate climate, with an average temperature range of 15-20°C (59-68°F).
Soil requirements
Bohemian knotweed prefers moist, fertile, and well-draining soils. It can grow in a variety of soil types, including sandy, loamy, and clay soils, as long as they have a pH range of 5.0-8.5. The plant is also tolerant of mildly acidic to mildly alkaline soils.
Overall, Bohemian knotweed is a hardy and resilient plant that can adapt to different growth conditions. However, to ensure optimal growth and development, it is crucial to provide the right amount of light, temperature, and soil conditions.
Cultivation methods
Polygonum ×bohemicum, commonly known as Bohemian knotweed, is a perennial plant that can grow up to 1.5 meters in height. It prefers well-draining soils with sufficient organic matter and full to partial sun exposure. The plant can be propagated through root division or from seed, although division is recommended due to the low germination rate of the seeds.
Watering needs
The plant requires regular watering, especially during the growing season, to establish deep roots and promote healthy growth. However, overwatering should be avoided as it can lead to root rot. The frequency of watering should be adjusted according to the climate and soil conditions.
Fertilization
Fertilization is essential for the healthy growth of Polygonum ×bohemicum. A balanced fertilizer with an NPK ratio of 10-10-10 or 14-14-14 can be applied in early spring and mid-summer. Alternatively, organic fertilizers can be used to improve soil fertility.
Pruning
Pruning Polygonum ×bohemicum is not required, but it can help to shape the plant and control its spread. The plant can be cut back in the fall after it has gone dormant, or in the spring before new growth appears. Dead or damaged stems can be removed at any time of the year to promote new growth.
Propagation
Polygonum ×bohemicum (J. Chrtek & Chrtkovß) Zika & Jacobson is a hybrid plant that can be propagated through division, cuttings, and seeds.
Division
The easiest and quickest way to propagate Polygonum ×bohemicum is through division. This can be done by digging up the entire plant and carefully separating the clumps or rhizomes. Each division should have a portion of the root system and several stems. Replant the divisions immediately in a prepared bed or container filled with nutrient-rich soil.
Cuttings
This plant can also be propagated through stem cuttings taken in the spring or summer. Select a healthy stem and cut it just below a node or leaf. Remove the lower leaves and dip the cut end in rooting hormone. Plant the cutting in a pot with well-draining soil and cover it with a plastic bag to retain moisture. Keep the cutting in a warm area with bright, indirect light until new growth appears.
Seeds
If you wish to propagate Polygonum ×bohemicum from seeds, it's important to use fresh seeds for the best result. The seeds can be planted in a seed tray or directly into prepared soil in the spring or fall. Cover the seeds with soil and keep the soil moist. The germination process can vary, but typically takes two to eight weeks. Once the seedlings have developed several sets of true leaves, they can be transplanted to individual pots or directly into the garden.
Disease Management
Polygonum ×bohemicum, also known as Bohemian knotweed, is relatively resistant to diseases. However, it is prone to leaf spots, rust, and powdery mildew, which cause the leaves and stems to turn yellow and eventually die. These diseases can be managed through cultural practices such as crop rotation, regular pruning, and sanitation. It is also essential to ensure that the plant is planted in well-drained soil to prevent waterlogging, which favors the growth of fungal diseases.
Pest Management
The most common pests that attack Polygonum ×bohemicum are mites, aphids, and caterpillars. These pests cause stunted growth, yellowing of leaves, and distortion of plant parts. To manage pests, it is advisable to consider cultural and mechanical methods such as removing and destroying infected plant parts and controlling weeds around the plant. Biological control methods such as introducing natural predators like ladybugs, lacewings, and parasitic wasps can be effective in managing aphids and caterpillars. It is also possible to use insecticidal soap and neem oil to control mites and aphids effectively.
