Heavenly bamboo. It has it's good points. I remember a long time ago walking around an elegant section of town and admiring the tall stems and bright red berries on clumps of Nandina domestica near the front door or steps of many of the houses. I enjoy the lush clusters of berries, bronze in the fall and lipstick red in winter. I like that they are evergreen and also often have red leaves in the winter.
They require no fertilizer or supplemental water. It's nice, in a way, that you can cut them down to the ground and they will grow back again as full as ever. They're great for something like hiding the utility cap on your cable TV access point. If the cable guy needs it cut back, it'll recover quickly.
But the biggest strength of Nandina is also one of its biggest drawbacks: it is very hard to kill. You can have too much of a good thing. I have basically a solid wall of Nandina six feet tall and 90 feet long that was planted by previous owners of my house.
It's partly my fault. They were more spaced out and not this big when we moved in, but they spread slowly and steadily, and I have been all but helpless in the face of the behemoth until only a year or two ago. I had tried pruning it, then hacking it, but it kept coming back. I had tried digging it up, but could only make a dent on small isolated clumps. "Making a dent" in fact, is what the Nandina did to my square-tipped spade when my husband tried to dig some up a few years ago. The blade was bent badly enough it had to be replaced.
Now I have developed a system. I wish I had figured this out a long time ago, because the Heavenly bamboo hedge is going to take a lot of work to vanquish, but at least now I know how to attack it.
Here are my weapons:
Step 1: I cut off all the berries on the clump I'm going to work on. This is going to be a violent battle and if I knock off a ton of berries, I'm just going to end up with clumps of seedlings. I usually do find a small number of seedlings a few months after removing a clump anyway, from the years-worth of berries that have already dropped, but it makes me feel better to think I'm not sowing the seeds of my enemy. I don't put these in the compost bin either; I throw them in the trash. I don't know if this is overly cautious or not.
Step 2: I cut off the tops with long-handled loppers down to about a foot tall. This is enough to remove most of the leaves and small branches, so I can see what I'm doing without getting leaves in my face, and enough is sticking out of the accumulated leaf mulch so I can see where the stumps are and not poke myself in the foot with them. I pile the stems up either behind my compost pile or behind my shed. The do a pretty good job of suppressing weeds in these spots while they break down. The leaves fall off and mulch the ground after a while, and I sometimes retrieve a few stems later to use as plant stakes.
Step 3: Now for the real heavy-duty work. I rake up the mulch and dig up the Nandina by the roots a little bit at a time. This is a bit of work, but not nearly as hard as trying to dig up a whole clump. I have no desire to replant this stuff so I can go after bite-size pieces. First I cut around a small section on the edge of a clump. Generally, it's easy on the outside: I just use the spade to loosen the soil around the edge. On the inside of the section, it takes a good tool to cut. I don't do it with the spade, because I don't have that kind of back strength. Instead I use either a mattock (if there's room to swing it) or the drop bar shown on the right edge of the group of tools. The blade on this tool is relatively small and easy to get into a tight spot, but instead of using your foot and your body weight to cut, you are mainly using the weight of the tool. It sometimes takes three or four blows to cut through a typical Nandina root, but it's not too hard on my back. On the first pass, I don't worry about cutting every root, since I can't see what I'm doing anyway. But I'm trying to loosen the clump enough to lift it with the spade (without damaging the spade or my back). It turns out that Nandina roots are not very deep at all, just a few inches, so once I have things loosened up, I can slide the spade underneath and start lifting. This makes it much easier to see where to make the next cuts. Now it's a straightforward matter to cut the rest of the roots to remove the first segment, and start targeting the next segment. Working around the edges of the clump, each segment is easier to get out as the roots are all being lifted and loosened.
Here are the roots of a patch I was able to remove in about 30 minutes of work.