Question from Clyde in Minnesota:

The part of a mushroom that we see aboveground is its "fruit" and may contain thousands of tiny seeds called spores. Each spore grows a threadlike root when it falls to the ground, and the roots from many spores weave a huge underground web. Whenever two roots from different spores meet, they can join to make a new mushroom.

To get rid of your mushrooms, you'd have to remove all the dirt that contains either roots or spores. (By the way, you may be spreading both when you shovel them 'shrooms.')

Even if you found a poison that would wipe out this batch of mushrooms, airborne spores of the same species (or another species) could easily grow more mushrooms in the same spot as long as conditions are favorable.

Your best long-term solutions? Change the environment or build a garden around the mushrooms. The latter might be easier, so let's start with it.

Stop mowing (and shoveling) the area. Put an edge around it to set it off from the "real" lawn. If you have a collection of cement bunnies or gnomes, arrange them artistically among the long grass and mushrooms.

Casually mention to visitors how hard it was to get that colony of mushrooms to establish. Toss out a few fascinating facts about mushrooms (Did you know that the inner flesh of Gyroporus cyanescens turns bright blue when exposed to air?). Any visitors who notice the mushrooms will quickly be convinced that you are not a lazy slob who lets fungi invade his lawn, but rather a connoisseur of unusual plants.

To draw attention from the mushrooms or even hide them from view, plant taller shade-loving plants among them. Here are some planting ideas:

• Sedge Meadow: Try making a meadow with easy-to-establish plants. Scatter shade-tolerant grass seed that has a high proportion of sedges, grasslike plants that grow in shady areas and shouldn't mind the acidity from the nearby pine.


• Plant a few shade-tolerant flowers like Cranesbill (Geranium sp.), which will creep through the sedges, and Coralbells (Heuchera sp.), which will raise sprays of flowers from a clump of short leaves. For more flowers, try overseeding with aster (Aster sp.)—choose hardy varieties that will be perennial for easiest care—and columbine (Aquilegia sp.).


• Cut the area once a year in early spring before trees start to leaf out. Let the mushrooms be part of the meadow, if they choose to stay.


• Woodland Understory: Turn the area into a woodland garden with easygoing spreaders like native ladyfern (Anthyrium felix-femina), Wild Ginger (Asarum canadense), and Jack-in-the-Pulpit (Arisaema triphyllum). Look in a local nursery for other native woodland plants. (Check out this list of Minnesota nurseries.)


• Shrubs and Groundcover: Acidic shade is a great place to grow our native Serviceberries (Amelanchier sp.); they produce edible berries and bright gold autumn leaves. Nurseries offer dwarf varieties if you have limited space. If you want to attract hummingbirds, try coralberry (Symphoricarpos orbiculatus), another native shrub.
  
  Under your shrubs, plant creeping groundcovers, but only if you have edged the area. Otherwise they'll creep right into your remaining lawn. Many nurseries offer these common species:
  • In moist areas, try Sweet Woodruff (Galium odoratum or Asperula odorata).
  • In dry areas try Creeping Thyme (Thymus vulgaris).
  • Lamium species will probably work in either dry or wet conditions; choose L. maculatum rather than L. galeobdolon, which is labeled "very invasive" in my A-Z Encyclopedia of Garden Plants.
  • Ajuga species need some moisture to establish well.

  Bluestone Perennials offers mail-order "six-packs" of groundcover seedlings in spring, and they often have a Buy 2, Get 1 Free deal. I've found them to be reliable and prompt.

• Hostas: Revered by many gardeners for their easy care and bold looks, hostas do best when shaded and can survive in either moist or dry environments. You may want to take a look at all the hostas that are available in a nursery or catalog nowadays; you'll be amazed at the variety of shapes and sizes and colors.

  Visit the Minnesota Landscape Arboretum and stroll through its woodland garden full of hostas for inspiration.

  In this case, you'll want hostas that spread out to cover the ground rather than those that grow up in a vase shape and hold their leaves above the ground. I grow a particularly striking gold hosta with huge leaves called 'Sum and Substance' that people never fail to comment on. One plant of that species would cover a three-foot-square section of mushroom-ridden ground.

  Hostas expand every year and can be divided into new plants. Ask ten friends, and I bet you can get at least ten hostas for free.

STRATEGY #2: "What Mushrooms?"

Now for the other option, changing the environmental conditions of the area to make it less appealing for mushrooms.

Mushrooms often grow on rotting wood, which may be located underground (decaying roots of long-gone trees, etc.). Rather than labor-intensive digging, which will likely damage the roots of trees now living and isn't guaranteed to get rid of the mushrooms, you could try covering the ground to change its conditions. Whether this is feasible depends on the size of the area in question and how close it is to your trees.

Whether it will work is unknown; I'm only speculating here, so don't go to a lot of trouble based on these suggestions.

• Large-sized Gravel: Adding gravel inserts more space between nutrient pockets. Gravel in which the individual rocks are an inch or more across may make it too energy-consuming for spore roots to find each other and create mushrooms. Top the area with a two- or three-inch layer of this type of gravel (make it no deeper than three inches near existing trees). Beware of using limestone gravel, which will raise the pH of nearby soil and stress your pine tree.

  You could go further and add a few boulders and larger rocks for decoration, making a dry garden. You could even build a cairn, a sculptural pile of rocks, as an ornament.

  However, gravel is probably not the best option if you have lots of nearby flowering plants that might self-sow in your gravel.

• Soil: If the area isn't under the canopy of a tree (you don't want to build up the area over a tree's roots), try making either a berm (a shaped hill) or raised bed (a framed planting area higher than the surrounding ground). This is a good option if you have another project in mind that will generate extra soil or if you have access to soil. It's also an option if you want more planting space. On the berm, try ferns and creeping groundcovers. In the raised bed, start a ginseng patch.

  I don't know if the mushrooms will be able to continue growing and reach the new soil's surface. If they do, revert to STRATEGY #1: "I'm Growing These Mushrooms on Purpose."

• Buildings and Furniture: Have you always wanted a gazebo? A garden shed? A hot tub? A patio? Maybe you can site it in the problem area. One caution: the lime in cement could stress or kill your pine tree if it's sited too near the roots.

STRATEGY #3: If You Can't Beat 'Em, Should You Eat 'Em?

You might be thinking you have a smorgasbord on your hands. Though eating them would be a clever way to get rid of them, don't eat the mushrooms unless an expert tells you they're edible. Some edible mushrooms look very similar to poisonous ones and can only be differentiated by things like their spore print (the pattern their spore fall in) or the color of the underside of the cap. You might be able to find a mycologist at the University of Minnesota who will visit and identify them for you. Or take a sample to a meeting of the Minnesota Mycological Society (for readers elsewhere in North America, find your regional mycological society.)

Wise gardeners often say a garden gets its unique character from just such a problem area as yours. Maybe you'll create a beloved garden in that very spot, or maybe growing healthy mushrooms will turn out to be more satisfying (or at least less work) than fussing over an unhealthy lawn.

Whatever happens, be sure to report back about your results!

Best of Luck,

Evelyn Hadden
LessLawn Editor

Do you have a question for the LessLawn editor?