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How long does Roundup last in the soil?
FAIRBRJU
Posts: 3
Hi - There's a potentially lovely rockery in my garden (newly acquired) that was hidden under a log-pile. Now that the logs have gone, the earth is full of ground elder roots that are difficult to remove. If I put round-up down and cover over for the winter, will it be OK plant up next year as I'm not sure how long round-up lasts in the ground?
Many thanks
0
Posts
The active ingredient in Round up is glyphosate which becomes de-activated on contact with the soil, so you can replant immediately.
However, glyphosate works when applied to actively growing foliage - it won't work if applied to roots at this time of year.
I would leave it until the spring, when the weeds are growing rampantly - apply the Roundup and leave for a few weeks until the weeds are brown and dead. That will show the roots are also dead. You may need to have a couple of goes at it but it will work.
Then you can get on with re-planting the rockery - it will take longer this way, but it will work.
Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.
Thank you - so should I just cover up the rockery for the winter and plant up next spring?
No point in covering it. Leave it as it is until spring and apply the Roundup when the weeds are growing vigorously.
Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.
Roundup is supposed to break down in contact with the soil - and I've never experienced any problems replanting after using it. I know some people on this forum think it encourages moss, or damages soil organisms, but I've never found this to be the case. Make sure you read and follow the instructions and recommended dosage; it's actually a bit late for maximum effectiveness this year I think, but might be worth a go... Presumably there are plenty of ground elder leaves still looking healthy and green? The weedkiller is absorbed through the leaves, and transfered down to the roots in time. I'd apply the roundup to the leaves and then leave it a couple of weeks before covering the whole lot up with black plastic or similar.
Sorry Dove - overlapped with you. On reflection, you're probably right about waiting until the spring. Roundup is expensive...
Covering the rockery will stop other weeds but the ground elder roots will survive and you need to uncover them in spring, wait for them to produce lots of foliage and then spray with Roundup and wait for them to completely die before pulling up the dead foliage. Ground elder is a tough weed and usually not killed by the first treatment either, so you need to wait for a few more weeks and then treat the new growth again. It usually takes a whole season to be completely rid of it. Don't be tempted to try and dig-out the roots after the first treatment as each broken piece left may grow into new plants and you'll be back to square one!
Many thanks everyone
Now is actually a good time to buy round-up!
Wilkinsons have are got lots of various weedkillers on offer. I was there today and saw stuff on offer but didn't pay too much attention to the price because I wasn't looking to buy any.
Nowt wrong with buying cheap now to use later on
Thanks Fruitcake
I've found it quite hard to find concentrate to mix lately. I don't want readymix, it's much more expensive
In the sticks near Peterborough
Not totally convinced about the complete safety of Round up. I carefully spot treated celandine, one of my bugbears, and I am pretty sure it saw off bulbs under the soil. Would hate to be dragged into court by Monsanto, tho'.