Weed clearance
By Sewerby
United Kingdom 
My son has just adopted a good size allotment site with good soil that has been cultivated in recent years. It is currently completely covered with early growth of Rosebay Willowherb. What is the best way to tackle this?
9 Apr, 2009
Answers
yes, the roots which are runners are a nightmare and if you snap them when digging up can just make them spring up somewhere else
unfortunately it'll have to be a systemic weedkiller(like roundup) or lot's of patience and contiuously diging out the new shoots, it will eventually die but will take some time
9 Apr, 2009
Double dig from one end to the other, it will take you about 3 days but will be worth it.
9 Apr, 2009
Previous question
As a gardener who prefers to grow by organic means as much as possible I hate to say this, but quietly now, roundup.
Rosebay Willowherb has strong, rampaging roots that can be the devil to dig out competely. I would suggest roundup now, leave it for a month or two to let the herbicide get right into the system and then dig the plot over to remove as much of the root as possible. This area can then be sown with some later season crops.
It is probable that the whole of the site is not covered in willowherb so he could start working the clean areas right away.
9 Apr, 2009