I have a large number of mature buckthorn shrubs in my yard that were there when I purchased the property. This is classified as an invasive in North America. Not only is it problematic in terms of spreading in my yard, it produces copious amounts of berries which birds then carry to other areas. When I go hiking in the area, I see these plants taking over and I really want to eliminate them completely.
This summer I started by removing branches from half a dozen or so and cut them down to low stumps. I then dug out the stump of one. It turns out that cutting them low was a bad idea because these are really tough plants and there were multiple thick roots extending straight down into the heavy clay soil. I really could have used the leverage to get at them. I spent probably 4 hours on the one plant and was exhausted. I have maybe 5, 6, 10 dozen more to go. Meanwhile they continue to drop berries like crazy and all the stumps that were no removed are resprouting. I tried driving some bits of copper wire into one on the off-chance that might kill it but that didn't seem to do anything.
I'm resigned to the belief that I will not able to remove them fast enough. I need to somehow kill these plants to stop the spread. The best resource I've found for advice on managing them is here. It mentions putting a can over them to prevent re-sprouting but I'm hesitant to cut them low and lose the leverage I will want later.
That leaves chemicals. The options listed on that site are:
- Glyphosate (Roundup)
I would really prefer not to use conventional herbicides for various reasons. I'm looking for other options that would be more along the lines of organic methods. If that's not an option, are there any of the above that are considered more safe. I say that knowing that often all that means is that we know less about newer chemicals. I'm just looking for information at this point.
I found a page saying that epsom salts can be used to kill trees. Anyone with experience using this approach? Any risks to this for the soil? There are some other plants in the beds that we would like to keep hoping they will fill in once the buckthorn is defeated.