Japanese knotweed has a reputation for rapid growth, but this invasive plant's growth rate does peak and trough over the course of a year.
The growing cycle can vary somewhat depending on what the weather's doing, but there is a reasonably consistent annual pattern. Here's a rough timeline of Japanese knotweed's growing behaviour from one season to the next.
Japanese Knotweed Growing Cycle: Season by Season
- SPRING - Japanese knotweed shoots tend to emerge in April / May, although they have occasionally been observed as early as March. Leaves will appear as the plant's growth begins to accelerate.
- SUMMER - Summer is peak growing season for Japanese knotweed. By June / July, the plant may be growing at a rate of several centimetres per day! The plant's height and density peak in the summertime; it can grow to more than 2 metres tall, creating a dense canopy that blocks sunlight and stymies plant growth below.
- AUTUMN - By late summer / early autumn, you'll be seeing clusters of cream-coloured flowers on your Japanese knotweed. The plant's growth slows down in the autumn, although this slowdown may take longer in the event of an 'Indian summer' (a period of unseasonably warm autumn weather).
- WINTER - During winter, Japanese knotweed dies back and enters its dormant phase. But don't be fooled: the plant isn't gone! Its rhizome root system will remain beneath the soil, ready to re-emerge when temperatures rise and spring returns.
Bear in mind that Japanese knotweed's growing season may be extended in the event of an unusually mild winter and/or a particularly hot, humid summer. Horticulture Week recently expressed concerns that Japanese knotweed may begin to appear earlier in the year as a result of unseasonably warm weather in early springtime.
If Japanese knotweed is running rampant on your property - and we are now heading into the most aggressive phase of the plant's growth cycle - Taylor Total Weed Control may be able to help. Our Japanese knotweed removal service will get this invasive species under control and limit its impact on the value of your property.
Give us a call on 029 2039 7554 to arrange a free Japanese knotweed survey and discuss a suitable treatment plan.
Contact Taylor Total Weed Control
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