Thanks floral. I have been living with the bishop's weed and I don't actually mind the look of it, but I don't want it to spread everywhere and it's difficult to access it on that slope to trim it or cut off flower heads before they can go to seed.

I don't think seeding is the main method if spread. That's usually from bits of root afaik. I can't see any way of getting rid of one plant without the other.

Oh Dear - this is a familiar nightmare. There is a fix...but not an easy one. In October...or whenever the soil loses its summer heat, you would have to dig out the whole area, pulling the aegopodium rhizomes out of each clump of pachysandra. This is usually a five year task for me when the invading couch grass eventually overcomes my perennial beds...and involves digging up every single plant - pulling the long stringy couch roots (bishopweed is not dissimilar) from every clump. I either heel in the perennials in a temporary holding bed or pot them up until I am certain there are no bits of root left. If done carefully, lifting with a fork rather than a spade, it is possible to pull great long skeins of roots out without breaking and leaving bits behind. This is really only worth doing in order to save precious perennials...and I have sacrificed quite a few and sprayed the whole lot off in autumn and again in early summer in some beds.

You could contain the spread by using a barrier method - overlapping roof slates, corrugated metal, bamboo edging etc.

Campanula, that sounds like a LOT of work! The pachysandra is not so precious to me that I am willing to go to that much effort, LOL. I was hoping that applying Roundup using a gloved hand to the bishop's weed only would work, but I don't know how easy it would to be keep it from dripping onto the pachysandra below.

I didn't make the suggestion to clear it by hand, saving the Pacydpsandra as you go, because you said 'digging it out us not an option'. If you were prepared to dig you could do it.

You could do a hybrid solution where you dig up some clumps of Pachysandra and clean off their roots thoroughly and pot them up somewhere. Then you nuke the whole area, repeatedly if necessary, killing everything, and replant your reserved Pachysandras next year.

But to be honest, I agree with Camp. Pachysandra isn't worth it, unless you really enjoy digging.

get up in an applicator.. like at the link ... fill with undiluted round up ....

get out there.. snip a BW down low ... and drop or two on the green cut ... repeat every 4 or 6 weeks.. when you see them regenerating ... sooner or later.. they will get the idea of who is in charge ...

its still a PIA job ...... but its easier than digging it all up ... lol ...

as you suspect.. its not really a spray type deal.. or you will kill everything ... and you may as well save the pachy.. what else is gong to thrive on that hill ...

ken

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That technique isn't going to work on a serious patch of Aegopodium. It's a perennial which produces hundreds of leaves directly from the ground in dense patches. There are no main stems. If you cut it it will just throw up new shoots. It would take many days to apply herbicide to every individual leaf stem. It would be like trying to kill a lawn by attacking the blades of grass individually. I'd kill the lot off and start again. Or just live with it.

I’d be inclined to live with it for now. Give it a solid border and watch for any escapees at joins and hit them with herbicide. When you have everything else under control with the house and garden, then consider whether it is worth nuking and replanting or just continuing to live with it.

I think living with it is the answer for now - I have much bigger fish to fry, including many more spots where bishop's weed has made an unwanted appearance. I will sink a deep border around the edges, though, to try to keep it from spreading further.

I have it and believe it or not, I was once a novice gardener who thought I could control it. Not! I have resigned myself to never getting rid of it but keep it from invading further afield by mowing the areas around the bed it is in. You could live with it and mow above it (hard to see in the photo if there is a planting or grass). So pretty much agreeing withNHBabs. Not only will it be all consuming to take out or selectively nuke, you the will have to plant and care for a new ground cover planting on a slope, what a headache.

Flippant answer: you don't need RoundUp, Total Wipe-out (not 'regular' wipe-out, that's just 7% vinegar with a 500% markup) might work too!

Slight more but still not too serious, you can buy 'cleaning' (10% acetic acid) vinegar in large quantities fairly cheaply, that will kill many plants, both when sprayed on leaves and allowed to soak into the soil.

Or (pay someone to) roto-till the whole lot and cart everything away.

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I have relatives dealing with similarly invasive plants, changing the environment or just mowing down everything with lawn mowers/weed whackers was all that could keep it in control. Years of pulling stems/vines was not enough.

Unfortunately, mowing anything on that slope is not an option - it's far too steep. The area you can't see directly behind the bishop's weed is a flat spot that I have mulched as a pathway to get out into the middle of the slope, but it's not wide enough for a mower. The weed is definitely trying to grow in there, but luckily foot traffic keeps anything from really growing there for long. However, it looks like those crazy stolons could easily grow under the path and start up the upper section of the hill, so I will definitely sink a border behind the patch to keep it from moving in that direction.

Moving?

Funkyhat, rototilling would not work on Aegopodium. Every snippet of severed root would simply resprout.

Btw, you can mow a steep slope with a hover mower on a rope.

I wasn't entirely being serious, to avoid confusion I edited the line.

Priorities, Biondanonima - keep it all vaguely one sort of length with a brushcutter...or just ignore it. And yep, keep up the barriers...and when/if you can be arsed, nuke the lot - once in autumn, just as the plants are pulling back into dormancy...and again when the new growth has sprouted with a good amount of surface area for max impact. Do it right and it shouldn't need to be repeated...plus you will have time to grow a cover crop - even grass or clover, once the spring treatment has done it's job.

alternative method ... drip or two in the center of each leaf.. and let it run down the petiole ... the leaf stalk ...

btw.. i use kitchen gloves that are chem proof ...

ken

Going to take hours and hours, ken. Pachysandra just isn't worth that imo.