I Can’t Grow Grass Under My Spruce Tree!

Posted by shane - July 3, 2011 - Environmental Disorders, Insects, Diseases & Other Problems, Weeds - No Comments

No kidding!  You know, this is one of the top 5 comments I hear all year, from various would-be clients.  It seems that most people have at least one big spruce tree in their yard, and more often than not, people try to do the impossible.  They attempt to grow beautiful Kentucky bluegrass under the canopy of the spruce tree.  Please stop it.  It’s an act of insanity and futility.  That cute little tree the kids brought home in grade 2 is now 30-40′ tall, they kids are gone, and it’s time for a change.  And no, it isn’t the acidity that is killing the grass.  It’s the dense shade and the drought (ie. the tree is out-competing the grass for water, nutrients, and light.)

Typical 20+ year old blue spruce with declining grass beneath. R.LePage photo.

Nevertheless, the crafty do-it-yourselfer tries a number of different strategies to grow that ever-important, flawless lawn.  They raise up the canopy of the spruce tree.  They fertilize, water, rake up countless bags of spruce cones and needles, pray, or whatever.  Most of the time, these things don’t work, and you’re left with either a mutilated tree, or patchy, weak turfgrass, or both.

My recommendation is always the same.  First I try to help people understand why the grass isn’t growing properly and why it isn’t likely to.  Next I offer the solution:  the mulched tree well, an attractive accent to the landscape that not only helps both the trees and the lawn, but showcases the spruce tree and adds interest to the yard.

So we start by gently stripping out  the old, declining sod, from the tree trunk out toward the dripline (the outer edge of the tree canopy.)  Spruce roots are shallow, so we take care to do as little damage to the tree as possible, knowing that it will recover and benefit from our efforts in the long-term.  I used a sod stripper to assist with this job where it was practical to do so.  Removing old sod is grunt work, and the machinery eases the burden somewhat.  At this point, we’re left with a bare tree well.  We chose a peanut-shaped well that started at the house, linking up an existing shrub bed, and returning to the house near the downspout of the eavestrough.

Sod removed and a clean edge cut. R. LePage photo.

So now, all that was left to do was to select and apply a suitable mulch.  This is largely a decision of the homeowner, the possibilities range from natural wood chip mulch, various bark mulches, and a myriad of stones, pebbles, or lava rocks.  Personally, I prefer a medium grind (1″ chip) natural wood chip mulch.  Why?  Because it looks beautiful, retains a nice colour as it ages, and breaks down over time, which feeds the tree and improves the soil condition.  It is low maintenance and only requires “topping up” every few years.

I avoid rock mulches because, as a maintenance professional, I know that these mulches are high maintenance, and you’ll spend countless hours trying to keep them clean and free of falling debris from the spruce tree.  Don’t waste your time.

Now, a lot of people, conditioned by the drone of endless landscape “professionals”, are wondering why I haven’t suggested that you install landscape fabric to control weeds.  Two main reasons.  It doesn’t stop weeds.  And second, because it inhibits the natural process of mulch breakdown, which improves the soil.  You effectively start to create a “soil” on top of a soil.  I promise you, the weeds will come.  You may have to hand pull a few weeds, or you may have to spot spray a couple of times per season with a bit of Roundup or horticultural vinegar.  That’s life in the ornamental landscape.

Apply your wood chip mulch about 2-3 inches deep and avoid mounding it up against the trunk of the tree.  The mulch should not contact the tree trunk.

Finished mulched tree well. R. LePage photo.

One last note about edging.  I prefer a natural edge with no artificial borders (ie. plastic, concrete, bricks, etc.), but a lot of people like formal edging material, and that is fine.  But please keep in mind that the tree will continue to grow and expand the diameter of its canopy.  A natural edge allows you to simply extend the well as the tree grows.  Permanent edging doesn’t, and over time, you might run into a similar problem of your lawn dying back in spots or becoming patchy.

I love grass and the trees, but I give them their space, so they can perform their best in the landscape.  It is also a lot less frustrating to maintain, which means you can spend more time on the deck enjoying your trees, and less time toiling beneath them.

(c) 2011 Shane LePage, Wild Rose Garden & Tree Service, Red Deer, AB, (403) 755-5899