If there's anything you want to know about gardening - get in touch

Professional services
My professional horticultural services

Need a speaker?
For horticultural societies & clubs

Garden Answers FAQ
Answers to commonly asked questions

Question time
How do I cope with flooding?
How do I prune clematis?
Why aren't my daffodils flowering?

Pest Watch
Vine weevil control
Whitefly control
Clematis wilt

Links
Links to useful websites

My blog
View my blog

Garden answers

Weeds

Here are the answers to some commonly asked questions about weeds and weed control.

If you are unable to find the answer here, then why not send me an e-mail

How do I control ground elder?

I would start by digging out as much as possible, removing all the white roots you find. Then I would treat the regrowth with a weedkiller based on glyphosate, such as Roundup. The best time to spray this is in the evening, and make sure the spray doesn't drift onto plants that you want to keep. If you've got lots of it 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 Weed Blocker, which will stop weeds coming through 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 root as possible and then treating the re-growth with glyphosate.

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 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, having removed as much soil as possible, to submerge them in a container of water for a certain period 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. 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.

Back to GardenForum Horticulture homepage

GardenForum: Somewhere to discuss horticulture & gardening