Aside from what is good or not good over tree roots, there are a couple of competing issues--what kind of "look" is most important and what kind of maintenance. Questions include, does the idea of a bit of straggly grass just offend you 'cause it's not neat and tidy;, could it just look best somewhat natural; or does the area really look quite shabb;, are you interested in creating a specific garden area and tending it? "Mulch" can give a uniform (though dull) appearance, but it then becomes a substrate for weed seeds; and also the grass will like to grow into it more than it did the bare ground--more so if you have an invasive grass species. It can be fairly easy to pull a few weeds out of mulch, but that depends. It depends on what's going on elsewhere on the property and in the neighborhood as to what seeds tend to crop up (?nearby maples? birds bringing specific seeds? ). Re: the grass, have to determine if need an impermeable, or nearly so, barrier between mulch and lawn. Then you have to think, mow-strip or weed-whack the edging. similar but not exact for a ground cover--barrier issues, some weeding. These chores then contrasted with the upkeep of weed-whacking the lawn grass and how it looks on its best day. The more the area is VERY inhospitable to plant growth--say because of root competition and dryness--the more you might be able to have a lightly mulched area that doesn't grow much. Also these issues are bigger or less big depending on the area you are dealing with--if a small area, you could try most anything and not lose too much. If a very large under-tree area, then more planning required.

The soil under large trees is often too dry to grow grass due to the sheltering aspect and also because trees take all the moisture to grow. The soil is also often devoid of nutrients because the trees have taken it over years. One can replace the soil as much as possible and water but it's a continuing problem. I have an island of spruce, fir, and aspen in my front yard and have amended the soil, planted shade plants on the north side and perennial ornamental grasses on the south side. Not a perfect solution but easier than trying to grow lawn grasses in a difficult situation. Every fall I rake the available leaves into that area and continue to amend the soil with whatever I can get and water as necessary.

The other crops are pretty boring like number one in beets, we have a sugar industry here. 6th in peaches I guess my point any place you live is what you make it. I have an orange tree, a black peppercorn plant, cacti, and fig trees. I can grow anything I want. I have a limited season, but the plants don't know that. Peppers and tomatoes are tropical plants yet grown everywhere. Both originating from South America. I hate our winters, but we don't have poisonous spiders or snakes, no hurricanes, or earthquakes, just an occasional tornado. Cost of living is really decent here too. I own waterfront property but am middle class, hard to do in CA or FL. Everyplace has it good points and bad, it is what you make of it. I have often thought of moving but many of the things mentioned changed my mind. I'm excited this week I have all kinds of new plants coming. Spring is at last here, and after the hard winter, the roses never smelled sweeter! I have Nadia the cherry-plum hybrid tree coming. It's like a huge cherry! Developed in Australia. You couldn't grow that in FL, not enough chill hours. Two elderberries new cultivars from the Netherlands that are pruned like raspberries, making management and harvest rather simple. Two new currants, a pink, and a red one. Again cannot be grown in CA or FL due to these cultivars not taking the heat. I picked up three more blackberry plants, and a tropical fruit tree, that produces the sherbert berry. I will have to overwinter inside. This cultivar is from India. I added two plum trees Satsuma, and a weeping Santa Rosa plum. Both are very good Japanese plums. My raspberry crop is going to be huge this year, as is my strawberry and blackberry crops. I have garlic, and onions planted out already and have 15 tomatoes, and 15 pepper plants ready to be planted out. My Spice Zee nectaplum has swollen blossoms, about ready to bloom, As does my pluot tree, and Indian Free and pf-Lucky 13 peach trees. Also my Arctic Glo nectarine is loaded with fruit buds. The blueberries are going to produce a large crop, as our my currants too. Getting ready to plant beans, cucumbers, melons and watermelons. I'm growing orange, yellow and red watermelons this year. Have a good spring everybody!

if the goo is labeled for this as a proper use.. knock yourself out ... dont take any guilt trip over such ... IMHO .. a few inches of dirt is NOT going to kill nor harm this tree ... crikey.. 95% of its roots are probably way beyond the spot you are working .. but that said.. ITS A TOTAL WASTE OF MONEY ... to buy the dirt ... as i swear.. within minutes.. the maple will have grown feeder roots into it.. to re-establish its dominance... you are not going to fool this bat turd with a little paper or card board ... if you want to TRY ... just dig out small holes.. in native soil .. bare root your plants.. insert.. and water the devil out of them until they have a chance to compete with the monster ... ALWAYS broadcast water.. and NEVER fert just the babe ... else guess where the tree will grow new feeder roots .. which will choke out your plants ... the idea is that you are trying to fool the tree.. into not knowing you are trying to plant other stuff under it ... and with the experience of growing 1650 hosts under trees ... i kinda have some experience with such ... since i have the generic RU ... i would spray now... wait a few weeks.. to see what i missed ... [mostly because the grass isnt even greening yet in MI] ... then respray.. and just cover with 3 or 4 inches of good bark chunks ... the extra inch.. so that when it settles .. i will have the requisite 2 to 3 ... you can.. immediately.. plant in the dead grass .. [do try not to walk thru your killer.. get your shoes all wet with such.. and then walk across lawn you want to keep.. been there done that ... and with a garden tractor .. weeks later.. wondering what the heck all those lines in the lawn were.. lol] and anything that pokes thru i would spot spray with a windex type hand spraying during the growing season ... again .. the added soil.. is a waste of time and money.. and will only stimulate the tree to attacking whatever you plant in it ... ken