The fence delusion

Where I live, a lot of yards are fenced. We found a cedar stockade fence enclosing our fifth of an acre lot when we moved in. Now that we have a small fish pond, we’re legally obligated to maintain the fence to keep people from drowning. That fence can sometimes fool me into thinking my garden is separate from the rest of the neighborhood. The enclosed yard feels like a separate ecosystem, even though it’s not.

            The tendency to put faith in fences reminds me of the day when we first brought our dog Nadia home from the shelter. We opened the hatchback and let her jump into the far back of our station wagon, imagining she’d know to stay there. Of course she quickly jumped over the back seat and landed in our laps, happily oblivious to our idea that the seats were for humans.

            Only humans recognize our property rights. Like Nadia jumping into the front seat, the wild animals in my yard don’t let artificial boundaries deter them from roaming free. To a raccoon, the fence is probably like any other geographical feature, less interesting than a tree or a pond. When male chickadees maintain and defend territory with their song, they don’t set boundaries by my fences. And fences don’t keep wind-borne seeds from leaving my yard.

            In suburbia, good fences don’t make particularly good plant neighbors. If I grow invasive plants, imagining that I can keep them under control, it’s unrealistic to think they’re going to stop at the fence line. I’m growing a silk tree (Albizia julibrissin), a species from the Middle East and Asia listed as invasive in the Southeast US but so far not in my home state of Massachusetts. I’m attached to that tree because I grew it from a seed that I got at a propagation course. It’s at the edge of its hardiness here, but it has grown steadily, and a few years ago it added bottlebrush pink summer flowers to its attractive feathery foliage.  

Silk tree--the view from below

It also started producing lots of seed pods, and I started pulling its seedlings. 
            With climate zones creeping northward, I may be acting as my neighborhood’s Johnny Appleseed for silk trees. I can say I’ll track the seedlings and pull them all out. I can actually do that in my garden, but local custom doesn’t permit me to barge into my neighbors’ yards even for purportedly neighborly weed pulling. And if I dropped dead tomorrow, the silk tree would have reproductive free rein.

            So it probably doesn’t make sense to keep the silk tree. Right now, my goal is to add native plants to my garden and invite in native insects and birds. The nonnative silk tree is a beautiful zero in that regard. Eventually it may have to give way to a native. This could be my chance to try growing a persimmon tree.