I'd definitely go to the effort of removing both the ivy and the vinca. This is not a good situation for either and ivy in the ground in Seattle is just not a good idea, even when restricted in where it can travel, as it appears to be in this case. The hebes can be pruned back quite hard and now is a good time to do so. They won't look great for a few weeks but they are flushing new growth now and will fill in rapidly. In the future, a light trimming on a regular basis should keep them from getting too leggy. Same with the heather, which should be sheared back annually after bloom. In such a small planting area, a groundcover may not even be necessary if you select other plantings carefully for size and spread and mulch around them. What you decide to plant is up to you but I wouldn't pick many different kinds of plants. A few that will remain in proper scale for the size of the planting area, offer a contrast in texture and form and provide some year round interest/color is all you need. And there's always room for a few spring bulbs, but maybe I'm offering that suggestion because they just look so appealing right now after our long winter and cold, late spring :-))

I live in a different climate, but something has always worked for me. Cover the area such that light will not get trough, for over a year. and rarely 2 or 3 years until the roots will die as well. I noticed that it's better to let the plant grow under the cover - as it'll pump the plants resources faster and make them more vulnerable to insects and mice. I'v covered areas with stones, cement, carpets and black nylon. My preferred method is two layers of old carpets and one layer of black nylon. (and some salt), like this side view: [stone] [stone] wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww upper carpet s s s s s s s s s s s s s s s s s s s s s s a little salt wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww lower carpet PPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPP plants the salt (really a little, should be invisible on the carpet) will keep the carpets wet, thus limit gaseous exchanges (may do some burns to the plants), and combined with the black nylon, it's a real oven during the summer. Put something heavy (Like stones) on top and around it. Top view: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX X~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~X X~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~X X~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~X X~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~X X~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~X X~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~X X~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~X X~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~X XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX X are stones or whatever. Make the best effort to prevent light inside. When I need it to look good, I use synthetic grass on top, in this case use only one layer of salted carpets, then put the black nylon layer, and then the synthetic grass on top. I hope it can help in your case

I planted mint in the ground out front about 10+ years ago. I have spent every year since trying to get it out. I tried everything, including Round Up. It doesn't care if you pull it up, spray it, etc. I planted an herb and vegie garden out back last year and wanted assorted mint plants. I put one in a sunken pot in my garden, (I did not cut the bottom out as some suggested, thank goodness!), the roots grew through and it started to pop up all around. I think I got it out, this year will tell. Do NOT plant mint in your garden, unless that is all you want to grow. Get a big pot and it will do just fine. I have had spearmint, orange mint and chocolate mint that have grown for years in a pot. Tried apple mint last year and banana mint new this year, (don't think it is very "banana-y")

I have been thinking about this protein poisoning, and I do believe it can happen. One of the things I remember reading, if the worms ingest food that has not decompose, the food will form gases in the worms' intestine. This will cause bloating, bursting or the string of pearl effect, being such delicate creatures. This will most likely happen with starchy food. I guess that would be things like rice, pata, potato or even banana that is not rotten. Mind you, I am no scientist. I am just guessing. If we eat rice , potato or pasta that is not completely cooked, we will have a stomach ache too. Imagine that happening to such a tiny worm compared to our size. That is also why I don't blend the worm food so they won't be able to swallow particles that are not "worm ready". I do chop, cut or slice them (the food) down to save space in storing and to make it decompose faster. A good thing not to chop or cut the food (i.e. apples and the like) if you are planning to go away. It will push the availability date to the worm further. We know they will not go hungry since they will keep reprocessing the VC and eventually eat the bedding, but ,,,,, My apology to the original poster. This should have gone under a separate thread. Otis