Suppressing invasive weeds

[Cheryl]

Hi, I have recently purchased a property which backs on to land on which giant hogweed has been growing. This has been reported to the landowner who has treated it, although apparently he did the same last year and it has returned. My problem is that the previous owner of my house (who wasn't a gardener!) allowed seeds of this plant to grow on this property. He seems to have tried to solve this by digging up the weeds and turning over the soil leaving a very untidy, uneven surface and more plants were starting to come up this season. I treated the whole garden with total weed killer (it is very small, only about 30 sqm in total), cleared the dead plant material and then laid a weed suppressing membrane and covered it with bark, just to try to make the area look reasonably tidy. I am now noticing that the soil appears to be raising up in some areas even though I did my best to level it before putting the membrane down. It is becoming quite uneven. Do you think this could be due to rain washing soil away in some areas and not in others. I have lifted a bit of the membrane but can't see anything growing underneath that may be causing this but I am reluctantly to take up the whole lot and re-level. Has anyone else ever had similar experience?

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Or any advice on getting rid of giant hogweed in general would be much appreciated. Thanks.

[SueA]

Hi Cheryl & welcome to the forum. I've never had to remove Giant Hogweed & think it's an awful task, we see a lot of it along a river not far from us & they have been trying to get rid of it for years. Apparently summer is the best time to treat it with weedkiller when it's started to throw up flower spikes but before they actually flower & produce seeds so maybe there wasn't enough topgrowth when you treated the garden? Other than that digging out the roots should get rid of it so it's possible that some roots were left in the ground & are now starting to grow again & pushing the soil up underneath your membrane? It's such a shame that you've got to deal with this when you've moved somewhere new & were probably looking forward to planning your garden, the landowner behind you could be reported if they haven't cleared it properly. I know if there's Japanese Knotweed around somewhere you're buying it has to be cleared before you can even get a mortgage on a property - this happened to a friend of ours & she ending up buying elsewhere as it was taking so long. I hope the uneven ground settles for you otherwise I'd try raking the bark mulch off to one side if poss. & lift the membrane, dig around a bit to see if there are any obvious roots, if not try & flatten the ground & put the membrane back. Good luck.

[sweetpea]

I have hogweed, not the GIANT hogweed in the 'Wild' part of my garden. When in flower it attracts many insects and so I leave it. however I cut down the seed heads as it would seed everywhere. occasionally I dig some out which is not too difficult a task even for me (I'm an old git)
Wear protective clothing when dealing with giant hogweed as some folks get a bad reaction if coming in to contact with skin.
I would agree with sue about what to do.
ps welcome to forum.