Hello - never posted here before.
Reading everything I can about eradicating comfrey.
We didn't know about the sterile variety and we went all in planting two massive rows of the stuff about three years ago. Last year, I chopped and dropped about 6 times over the season and lay all the leaf mulch around fruit trees. I appreciate all the nutrients but I can't stay on top of the harvest and it's spreading into other parts of the garden (seeds) so we want to kill it dead, even if it means we lose that growing space.
I saw the comment about covering with plywood and wondered how long it takes for it to kill the comfrey and, given there is a substantial and strong root underneath, if there is any chance it could come back once the ply is removed? Sadly, we are talking about a substantial area so I need big solutions - we have some scrap metal sheets and silage tarp that we are hoping to use for this endeavour.
Bed 1 - about 30 plants sandwiched between a dense planting of sun chokes on one side and herbs for tea on the other (lemon balm, hyssop, bee balm). (about a 40 foot row)
We had some sheets of old metal roofing so I've covered the row with that and weighed it down with logs. I am planning to leave that row of metal in place for at least a year, maybe two, but would leave it longer if there is a chance that the comfrey will come back from the roots. Thoughts?
Row 2 - this one is trickier. We planted another 12-15 comfrey plants along a row of hazelberts. The seeds clearly dropped and there are millions of baby comfreys coming up all over the bed! The best I can come up with is trying to dig up the hazelberts, shake off all soil, and transplant them (to where I don't know) and cover the entire bed in silage tarp for one or two years. Or, we can try to leave the hazels in place and cover the bed in either black bio plastic or silage tarp and do our best to cover all the comfrey and leave the hazels exposed, but I'm worried about the efficacy of this and whether the heat / solarization of the bed will ultimately harm the hazel roots anyway. This is another massive 'bed' about 5 feet wide and 40-50feet long. It's got grass that gets mowed on one side and sedge/reeds/ marsh grass on the other so I suspect that the comfrey shouldn't have much success outside the bed.
Anyway, thank you for reading. This feels like one of those big and painful gardening lessons that we just had to learn (research varieties and start small!!!) but I would love to tackle it and regain those growing spaces one day if possible. Your advice and insights are greatly appreciated!
JJ
