Reynoutria japonica, synonyms Fallopia japonica and Polygonum cuspidatum, is a species of herbaceous perennial plant in the knotweed and buckwheat family Polygonaceae. Common names include Japanese knotweed and Asian knotweed. It is native to East Asia in Japan, China and Korea. In North America and Europe, the species has successfully established itself in numerous habitats, and is classified as a pest and invasive species in several countries.Japanese knotweed has hollow stems with distinct raised nodes that give it the appearance of bamboo, though it is not related. While stems may reach a maximum height of 3–4 m (10–13 ft) each growing season, it is typical to see much smaller plants in places where they sprout through cracks in the pavement or are repeatedly cut down. The leaves are broad oval with a truncated base, 7–14 cm (3–5+1⁄2 in) long and 5–12 cm (2–4+1⁄2 in) broad, with an entire margin. The flowers are small, cream or white, produced in erect racemes 6–15 cm (2+1⁄2–6 in) long in late summer and early autumn. Related species include giant knotweed (Reynoutria sachalinensis, syns. Fallopia sachalinensis, Polygonum sachalinense) and Russian vine (Fallopia baldschuanica, syn. Polygonum baldschuanicum).
Japanese knotweed has strong resistance to disease and is usually not vulnerable to illnesses. However, it can be affected by pests and diseases present in its surroundings. These infections are typically mild. In terms of care, the plant requires a moderate level of maintenance. It should be pruned regularly to maintain a pleasing appearance and support healthy growth. Fertilizing can also help encourage flowering. Japanese knotweed is suitable for anyone with outdoor space, such as a garden or patio, and does not demand extensive gardening experience. It may require additional care when grown indoors.
How to keep Reynoutria Compacta.
Light
Despite its ability to survive in less light, Japanese knotweed prefers a habitat where sunlight is plentiful for optimal growth. This plant originated from regions with ample sunlight and flourishes more in those conditions. Both excessive and inadequate sunlight can hinder its development. The requirement for sunlight by this vegetation remains consistent throughout all stages of its growth.
Temperature
Originating from Japan, where the yearly average temperature ranges from 59 to 64 ℉ (15 to 18 ℃), Japanese knotweed adjusts its growth and energy conservation according to the temperature. It thrives best in a temperature spectrum of 41 to 95 ℉ (5 to 35 ℃). During summer, the plant can adapt to temperatures that surpass its preferred range by slowing down its growth and preserving energy.
Fertilizer
For Japanese knotweed, one application of fertilizer in the spring is commonly adequate, though monthly or every one and a half month feedings could boost its growth. Fertilizing improves the look and performance of the leaves, fostering uniform color and ideal texture. Moreover, it encourages the development of roots and the absorption of nutrients, ensuring the plant's health in the long run.
Botanical profile.
- Plant Type
- Herb
- Life Cycle
- Perennial
- Genus
- Reynoutria
- Family
- Polygonaceae
- Hardiness Zone
- 4-10
- Mature Height
- 0.91 m to 2.13 m
- Mature Spread
- 0.91 m to 6.1 m
- Leaf Color
- Green, Blue, Red
- Leaf Type
- Deciduous
- Flower Color
- White
- Flower Size
- 2.54 cm
- Bloom Time
- Mid spring, Late spring, Early summer, Mid summer
- Planting Time
- Spring, Autumn
- Harvest Time
- Mid summer
- Native Area
- Russia, Vietnam, Japan, Koppen, South Korea, China
Other names.
