Buckthorn oblivion

We put up the fence in our backyard 17 or 18 years ago, when our two oldest kids were little and the other two hadn’t come along yet. Our property extends to the bottom of the slope behind the fence, but since the fence went up I’ve mostly ignored the horticultural goings-on back there.

So, there’s this plant called buckthorn, Rhamnus cathartica, an ecological threat in Minnesota and much of the rest of the midwest. You may have heard of it. I’d certainly heard of buckthorn, too, but most of what I heard mentioned its invasiveness in natural areas. I don’t usually think of my suburban yard as a natural area, so I didn’t pay much attention.

Fast-forward through several clueless, happy years to 2016, when I realized that all of those little seedlings I was weeding out of my flower beds were buckthorn. Where were they coming from? Probably from the 15-foot-high buckthorn thicket that was steadily growing behind the fence.

Buckthorn-layer

About 80% of the lovely greenery visible behind the fence is buckthorn. Here’s what it looks like up close:

Buckthorn-behind-fence

If there was ever any sort of vegetative ground layer, it’s gone for now. I’ve spent some time over the past few days beginning to cut back this thicket. I’m using this method (scroll down to the subsection entitled “Light weapons and a long timeline”). I already had Trimec in the shed. I ordered the blue dye and sponge applicator bottle from Amazon. [Update 6/15/18: The smaller stumps treated with Trimec are dead, but many of the larger-diameter stumps have re-sprouted. Glyphosate (Round-up) might have done a  better job killing the larger plants. I ordered some Buckthorn Baggies to try on the vigorous sprouters. I’ll let you know how that goes once I get around to putting them in place.]

trimec.jpg

Treated buckthorn stumps (the dye faded quite a bit in last night’s rain):

Treated-buckthorn-stumps

Here’s my brush pile so far (plus more waiting to be retrieved from behind the fence):

Buckthorn-pile

It’s a big chore, but I’m looking forward to seeing what shows up (besides lots more buckthorn seedlings) once some dappled sunlight can reach the ground again. [Edit 10/19/17: Did I say “dappled shade”? Now that the buckthorn is gone, it’s a sunny south-facing slope!] I’ll probably also toss some native savanna/woodland seeds back there to help things along. I’ll post an update or two down the road.

 

Why “Cannon Avenue Savanna”?

The title of this blog, “Cannon Avenue Savanna,” tells you the name of my street and reflects my personal goal to gradually replace most of the non-native plants in my yard with plants native to the Twin Cities area (east-central Minnesota). The Twin Cities and surrounding suburbs exist on what used to be a mosaic of tallgrass prairie, oak savanna, and maple-basswood forest. We have two maples (one native, one not) and no oaks, but because of the amount of tree cover on our property (plus the shade provided by the house itself), we’ve got more of a savanna landscape than pure prairie or forest.

We have an established wildflower garden on the east side of our yard, but much of the rest of the yard is filled with non-native plants. Some are innocuous, like hostas; others tend to escape cultivation and show up where they’re not wanted (barberry1, buckthorn, orange daylilies2).

An older friend observed the other day that it seems like there aren’t even half as many butterflies as when he was a boy. But when he was a boy, there was a lot less hardscaping and turf grass. More land was covered by woodland, orchards, unkempt meadows, and farm windbreaks. Pesticides and herbicides were used, but not to the extent they are today. There was more tolerance for yards to be a little weedy and disheveled, at least around the edges. With bagging mowers, leaf blowers, and pump-sprayers in every shed, our standards have risen.

Most of us go with the flow, planting whatever catches our eye at the garden center, maintaining our lawns, cleaning up yard waste every fall. But did you know that cleaning up leaves and dried stems in the fall is yet another blow to butterfly populations? I wasn’t aware until recently that many butterflies overwinter in garden duff as eggs, chrysalises, and even caterpillars. In my zeal to get things cleaned up in the fall, I’ve likely been sending baby butterflies to the compost site along with the fallen leaves and dried plant stems.

Goldfinches eat the seeds of my cornflowers, and some bees and maybe even a few hummingbirds visit my hostas. But do these plants host the native insects and the moth and butterfly larvae that provide food for animals higher up the food chain, especially birds? We know that monarchs need milkweeds, but many of us don’t realize that other species also have what are known as “obligate larval host plants”; Karner blues depend on wild lupines, fritillaries need violets, skippers utilize wild grasses, and several species need oaks, ashes, wild cherries, or willows.

See this post for more information on wildlife host plants and whether cultivars and “nativars” are as beneficial as “straight species.”

A little history (with before and after pictures!)

We bought our house in Arden Hills, a suburb just north of St. Paul, in 1998. Here’s what it looked like when we moved in. (We had already cut back the shaggy bushes on top of the retaining wall.)

Front-before

Back-before

Within the first few years, we had buried the power lines in the back yard, pulled out the overgrown bushes in front, and had the gray rocks from the retaining wall hauled away by someone who saw our ad on Craigslist. We had new rocks installed to create a rock garden by the driveway, and this is what things looked like somewhere in the early 2000s.

Front-2001a

Front-2001b

As time went on, we had the warped board-and-batten siding replaced, put up a fence, put in a boardwalk on the west side (where it’s always soggy in spring), made some adjustments to the back deck, and smothered the lawn and put in wildflowers on the east side.

Continued tweaking over the years brings us to the present day.

Front-2017

Back-2017

Side-2017

Getting better, and it only took 19 years! In addition to swapping out some of the non-native plants, I hope also to expand planting beds, add structure with more shrubs and native grasses, and continue to reduce the size of the lawn. I’ll share more about projects past, ongoing, and future in upcoming posts.