Sometimes I get so excited when I learn about a new plant that maybe beneficial to the garden. I can get carried away at times and want to plant them everywhere. However, there are certain plants that you should be very careful about planting in ground or in your garden beds.
I've planted 4 out of this list and boy do I regret it. Especially the comfrey!
1. Mint - I know from experience that mint can be a noxious weed and is very hard to get rid of. So unless you want to be spending the rest of your days pulling mint. I suggest not plant them in ground.
2. Penny Wort - I've always thought of penny wort as a pond plant. I've used it in my fish tanks and grown them submerged, so I figured they'd by more like a annual grown in ground. Well pennywort are quite hardy here. They are a very healthy plant to eat and drink but can throw runners out from long distances.
3. Comfrey - When I read about Comfrey, I was like wow how cool is this plant and I was immediately in love. It's a perrenial that acts a green fertilizer when you chop and rop. Well I've fallen out of love with this plant. It throws out think tap roots that go deep. And quite hard to dig out. Any small remnant will come back big and strong. I probably pulled out 50 lbs of plant material just this month alone.
4. Sunchokes or Jerusalem Artichokes - Another difficult tuber to get rid of. Do not grow these in ground or compost any part of it in your compost. It has a sneaky way of hiding in your garden bed and growing back the next year even though you may have pulled every single tuber out.
5. Bamboo - I do not have any bamboo in ground but I see this constantly at people's homes. Bamboo grow very quickly and can be quite invasive. They make for great privacy plants and can be useful support sticks when cut and dried but be careful about plant them in ground unchecked.
6. Creeping Jenny - Luckily I did some research on this on before I planted it. It is quite useful if you prefer not to constantly rebark every year in an area away from other plants.
7. Lemon Balm - I do not have any lemon balm but much like mint can get out of control in ground.
8. English Ivy - In general I hate Ivy. In highschool in San Jose I remember these were all over the base of the trees. I would always see little mice scurry from ivy to ivy. Those were not good memories.
9. Invasive Blackberries - I have a strong hate for invasive thorny blackberries. They grow rampant in every empty lot here in WA. Luckily this blackberry killer does the job reall well. It will kill them to the roots.
Learn more about WA state knoxious weeds here