Sunday, March 6, 2016

Tree Circles

I don't quite know what to do about the base of my shade trees in the middle of the lawn. Should I try to maintain a big circle of mulch around them, or let the grass grow up to the trunk? Either way is a maintenance problem.

The large red maple standing in the middle of our back yard had a circle of wood chip mulch around it when first planted. But it was constant maintenance to keep the lawn turf out of the circle, the mulch decayed into the ground at an alarming rate despite refreshing it twice a year, and without my intending it, the grass simply grew over the mulch circle.

It's a mowing problem now. Jim is careful to stay away from the trunk with the string trimmer or mower, but that means hand trimming around the base of the tree, which is completely silly. But we do it.

The same thing has happened with both black gum trees in the front lawn. The planting holes were raised and bermed a bit when both trees were put in, but the grass grew over, the circle diminished, and I could not keep up with maintaining the area grass free and mulched all season.

In the photo above the grass was making its forward attack and spreading all over what remained of the circle at the foot of this tree. I tried to dig out the edges and mulch and re-mulch often but lost the battle.

With the grass all the way up to the trunk, it looks odd, since the original lump of the bermed mulch circle is still raised, but covered with lawn now.

Trees were never meant to grow in grass. Grasslands are one thing, forests are another. They don't naturally grow in the same place. The lawn wants irrigation in summer but trees hate sprinklers splashing their trunks, which opens them to root rot diseases. Trees and lawn are not compatible.

And yet. I want shade trees in my lawn.

I have a young katsura tree that still has its original circle. It too was planted in a raised berm -- not a mulch volcano up against the trunk -- this tree is properly planted with the root flare showing, but the shoulders of the planting hole are above the lawn as it slopes away a bit.

Like the issues I had with my other lawn trees, the mulch under the katsura decays quickly and I can't keep weeds and lawn out of the circle despite reapplying wood chips multiple times a season.

On top of the losing battle with mulch, I actually dislike the look of big brown circles under trees, especially when there are several trees scattered about. Those big rings look so artificial.

Thomas Rainer agrees. Read his article about getting rid of mulch circles here. It's interesting.

A formal boxwood hedge around the trunks might be a possibility. It's artificial too, but at least it's green. It's another maintenance nightmare, though, what with clipping and shearing and the tendency of boxwoods in my climate to get winterburned and break apart from ice.

So . . . no to the boxwood hedge parterre.

An alternative is to underplant each tree with low shrubs. I've done that with each of the three white birch trees in the side yard. It's a challenge to grow anything in competition with thirsty tree roots, but the low junipers and some fragrant sumacs (dwarf 'Gro-Low') do well, and a catmint (Nepeta 'Dropmore') fills out the lower level in summer. This looks cohesive and natural.

I created these plantings when the birch trees were young. There is no way I can dig out lawn under that red maple in the back yard to get any kind of shrubbery in there now.

But I still might be able to underplant the two black gums in the front yard, which are small enough, perhaps.

But do I want a garden of shrubbery or even groundcovers around each tree? I like the idea of the open lawn leading down to the street. I don't want two fussy garden islands in front of the house.  But I do think that black gum tree looks isolated with its clompy bits of grass ringing its feet.

Will it look better if I can even out the lawn lumps with a bit of careful digging?

Will it look better when it's a mature, graceful tree with a big trunk, the way the trees in this park-like setting look in the lawn?
Photo from Thomas Rainer's article on getting rid of mulch rings

Although I like the way my white birch trees rise out of the underplanted junipers and catmint, I don't  think I want more garden beds all over the yard in every spot where a shade tree lives.

But I don't want those brown mulch rings at all.


  1. Just yesterday I was at a talk by Thomas Rainer. I did not know what to expect but as he explained his philosophy I realized I found a friend who thinks like me. So as a good friend I bought his new book today :)
    Personally I think the trees that are underplanted look fabulous. You don't have to have multiple shrubs and could for example try solomon seal with a low clumping ground cover, or try short grasses, or some other mixture that pleases you. Regarding the Black Gum you could also create a larger bed linking the tree to the driveway should you be feeling energetic :) Like you, I prefer the grass as opposed to mulch around a tree. I'd be interested in hearing what you eventually decide to do.

    1. Patty, I would love to hear Thomas Rainer speak! Just finished his book on Planting in a Post Wild World. How lucky that you got to attend his talk.

      I don't know what to do about the front trees, for some reason I just don't want to underplant the black gums in the front yard. You make a great suggestion about simple low groundcovers like Solomon seal, but I keep going back to the idea of a park-like lawn under the trees. Must think on this some more -- not sure what I want.