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Weeds and weed control
Help solve your gardening problem. Here are the answers to some commonly asked gardening questions about weeds and weed control.
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How do I control ground elder?
I would start by digging out as much of the ground elder as possible, removing all the white roots you find. Then I would treat the regrowth with a weedkiller based on glyphosate, such as Roundup.
Glyphosate-based weedkillers are sprayed onto the foliage of the weed, when it is actively growing - usually from April to September. The best time of day to spray is in the evening (as more chemical will be absorbed by the foliage), and make sure the spray doesn't drift onto plants that you want to keep. If you've got lots of ground elder you may have to make several repeated applications as re-growth appears.
The main problem with ground elder is its travelling roots. As a result, no matter how much you kill in your garden it will always come back from surrounding gardens/waste ground. That means you should try and put some sort of physical barrier in the soil; Root Control is very good for this. Or you could try growing a marigold called Tagetes minuta, which excretes a root secretion that helps stop ground elder from growing; it's available from Chiltern Seeds (www.chilternseeds.co.uk).
Around shrubs you can use Vitax Casoron G4 Weedbarrier, which will stop weeds coming through the soil for six months.
How do I get rid of bindweed?
There are two strategies to adopt with bindweed. Either keep constantly carefully digging it out as soon as it appears, or allow it to reach a reasonable size and then spray the foliage with a weedkiller containing glyphosate - such as Roundup.
I would start by digging out as much bindweed root as possible and then treating the re-growth with glyphosate.
The control of bindweed is similar to that of ground elder given above.
Any tips on how to get rid of pampas grass? We've tried killing it with a strong weedkiller, but it continues to thrive. Someone has suggested covering it in a plastic sack, but I'm not sure if this would be effective.
If I had to get rid of a pampas I would first cut it down to about 10-15cm (4-6in) from ground level (wear strong gloves as the leaves are razor sharp) and then either dig it out or treat the remaining stumps with Vitax SBK Brushwood Killer. This is best carried out in spring or summer.
The plastic sack idea revolves around starving the plant of light and so killing it. It would work, but it's a slow process.
I never know what to do with the roots of perenial weeds - especially bindweed and couch grass. Is it possible to submerge them in a container of water until they are dead and then put them on the compost heap?
You could do what you suggest, although getting the rotting/rotten remains out of the water might be tricky - or unpleasant! What I do is lay them out on a hard-standing area (I have an area of concrete) until they're completely dead - this can be as short as a few weeks in hot, dry weather to a few months if it's colder/wetter – and then put them on the compost heap once they're completely dead.
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