The sites are situated on the Cornish (western) bank of the River Tamar, 500 meters west and 700 metres north-east of O.S. Grid Ref: 452690. There were initially three growths along the river bank (map to follow).

It is difficult removing the roots of Japanese Knotweed as the roots can reach a depth of 7 metres.
Each remaining peice of root or rhizome, as small as 1cm, can produce new growth.

Site 2: This is the major area some 10 by 6 metres, abreast the bund, from river to drainage ditch. Data for this below and updates on the web log.

Site 6: In 2002 one plant was discovered and only noticed again in 2004. Since then there has been no regrowth..

Site 9E: (now D) This small patch was right on the river edge, and grew back only in the year of discovery, 2002. There has been no regrowth to date.

Site 2: 2008

The very high tide this winter breached the bund and washed away my stash of old rhizomes and stems etc. I found the bags and hopefully most of the bits ( as if ). -:- 12th May Found 8 rhizomes growing in drainage ditch :(.

The first pull was completed on 18th May. See  summary and/or download details. 

Site 2: 2007

The number in brackets denotes the amount of growths pulled, compared to estimated growth at the time.
    April 28th : 807 (60% of site)
    May 8th : 701 (regrowth and remaining 40%)
    June 16th : 206 (40% of site) regrowth much smaller here than other.
    Aug 27th : 308 (75% of site). Was worried about the long gap since last pulling, but growth overall was very little. The main growth was in the area least pulled i.e the centre by the drain. There are many other plants competeing now and most of the site is covered in other species.

The idea of leaving a small patch is that if the root structure is one rhizome then maybe the remaining part with above ground growth will draw energy from other parts of the rhizome and deplete its energy. Well I don't know if that is happening but it looks that way.
    Total : 2022 (Aug 27th)

Site 2: 2003

• 15th April
  • Main stand in Site 2 attacked.
  • Old stand burnt off, killing much of the new growth
  • Remaining shoots, some with roots pulled and burnt in situ.
  • The growth area, part of the bund, had been rebuilt with plastic netting to hold the soil together, probably as clay was not used. The netting was damaged in the burn. However it would have been very difficult to remove it to dig up the roots, so the damage has the benefit of making it easier to dig when appropriate.
  • Restocking the area with grass may be a good idea.
• 1st May
  • Some work done on site. Decided to bagup and leave until the weather dries to build a good fire.
• 29th May
  • Plants have grown six feet in 4 weeks. Lit big fire and cleared half. Most of the area near the last fire shows little or no growth
• 29th June
  • Cleared 90% of growth and burnt extractions. Dug only about a foot deep as the area is the river bund and soil is very loose, i.e. no clay.
• 23rd Aug
  • All the previously cleared area has growth about 2 feet tall. However other plants have started to co-habit the area, so the removal process is having beneficial results.
  • Pulled about one third which filled two bags. Will leave to burn later.
  • Decided that as a fair bit of root structure comes up with pulling, I'm going to continue this process for this year and see the results in 2004
• 25th Aug
  • Pulled another two bags. Will leave to burn later.
  • Will continue pulling and digging all through the winter

Site 6 and 9E: 2003

Site 9E

• 14th April: No sign of regrowth
• 25th April: Found two small shoots, very thin (3mm) one 6in the other 2 inches high in Site 9E
  • (where some were removed last year - see second bullet point below in year 2002)
  • Am not too happy that there still may be a bit of root as the tops snapped off.
  • Will monitor the site regularly.
  • Burnt pieces in stove.
• 1st May: No sign of regrowth

Site 6

• (1st February, 12th March, 8th April, 1st May)
  No sign of regrowth

Site 6 and 9E: 2002

• At the junction of plots 5 and 6 a single Japanese Knotweed was removed.(March)
• Plot 9E
  • 17th August: At the edge of the bank plot 9E, 10 stems were removed.
  • 31st August: the Japanesse Knotweed has started to sprout again.
  • 14th September the above Japanesse Knotweed was dug up and burnt with the previous stems and rizomeme/root structures.

 Summary 

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