Prolly not. Do you know what kind of grass? I have Bermuda, but fortunately it is a not-too mutant strain and does die with Roundup. You may have created a paradox of sorts--the landscape fabric of course can't really kill the grass, but protects it from your Roundup. So all the healthy roots are just there waiting to poke up here and there. Either you will have to be super aggressive with the Roundup and spray each twig as it appears, every day for weeks, and even then you may have lots going on underneath and just waiting for the right moment to grow, so you may have to re-prepare the entire bed. You're hoping, I guess, you can smother it. There aren't any real smothering products for sale for your purpose. Depending on what you've got planted, you might be able to remove (and save) the mulch, remove the fabric, Roundup what you can see, place thick layers of cardboard or newspaper over the grassy areas, and mulch over that, and hope it is not the super-aggressive Bermuda or something that grows through wood! So you can read and search about smothering grass, lasagna gardening, no-till gardening and lots of related things. People will tell you things will work or not work, but it all depends on what your actual garden area, plants, grass and so forth are like. So, I have no idea whether you've got a grass disaster or something salvagable. And it depends on whether you just missed a few roots or whether you just put your stuff over living sod of an aggressive grass. How did you actually prepare the bed?

A picture would be worth a thousand words here. Bringing in soil might be good if you suspect the original soil has been washed away for some reason. Some trees will react to hard soil by sending their roots out at the surface. Then as the tree ages, the roots become larger and expose themselves above the surface. If that is what has happened, then adding soil on top of the natural grade will cause you drainage problems and could cost you extensively if water pours into your basement (worst case). Adding soil should be done with considerable forethought as to the consequences. Another thought on adding soil is to keep it lower than the root bark on the trees. Tree roots flare out from the base of the trunk. If you bury the root flare completely, then you are burying tree bark. Tree bark will often rot when it is below the soil level. It is best if you leave some root flare above the soil level to be sure you are not burying tree bark. Tilling is a bad idea for many reasons. One of the obvious ones is that you have roots everywhere. You can't till tree roots. A much less obvious reason is that tilling destroys soil structure by fluffing it up. Once it is fluffy it has to settle again. That process takes 3 years. When it finally settles it will settle unevenly leaving your surface bumpy. Grass seed should never be mixed in with surface soil. It always goes on top of the surface. Many people recommend "scratching" it into the surface but that is not necessary. Nor is covering it with straw. All you need to do is loosen the soil at the surface (1/16 inch deep) before you apply the seed, then apply the seed, and finally roll the seed down with a water filled roller (rented). Seed should remain at the surface. If you insist on straw, as goren said, be careful not to use hay. Hay is forage for animals and has seed in it. Straw is the left over after the seed is threshed out. New seed must be watered 3x per day at breakfast, lunch, and dinner for about 10 minutes. The idea is to provide enough consistent moisture for the seed to swell and open (germinate). Unfortunately these are the exact conditions that crabgrass seed needs. For this reason grass seeding is most successfully done in the fall after crabgrass has stopped germinating. Also grass sprouted now will have weak roots that cannot stand up to the summer heat and dry weather. That might not be that much of an issue in your area. Don't assume you have clay. Fill a mayonnaise jar half full of dirt. Then fill the jar completely with water and a drop of soap. Swish it around and let it settle. You will see rocks and sand settling immediately to the bottom of the jar. In an hour all the silt will have settled. At that time if you have clay, the water will be cloudy. Let it sit another day and see if the water clears up. If it clears then you do not have clay. Clay will cloud the water for days and days. There are several conditions of minerals that cause soil to seem to be clay when in fact there is no clay at all. Don't be too surprised by this. Adding gypsum without doing this test and a soil chemistry test can be a mistake. I disagree with goren on mowing height. The only grasses that need to be mowed lower than 3 inches are bermuda, centipede, bentgrass, and some zoysias. Kentucky bluegrass (which you can't grow in shade) should be no lower than 3 inches. Fescues and all the other grass types should be mowed back to 4 inches. Usually this is a mower's highest setting. Grass grown in the shade needs to be longer simply so it can photosynthesize. Can you post pictures showing the tree roots and one from a distance showing the trees with the canopy?

Hi - I too am a 'newbie' to NC gardening and after living in/around Chicago for 50 years, this red clay has ALMOST done me in... I am convinced that whenI first moved here that FIRST I should have enrolled in 'pottery classes', invested in a Kiln and got rid of alot of this clay BEFORE I began bringing in mulch (14 square yds.) and top-soil (12 square yards of questionable 'dirt') and peat, more peat and MORE peat... ;-) It HAS been a very interesting 4 years since I have moved here. This is virgin soil that has NEVER been improved (I live in a mobile home park). I have even found a lot of arrowheads in the soil. Apparently people do NOT believe in 'improving' soil in trailer parks... ;-) I am the talk of the entire park for 'wasting' my time/$ on my yard, but I consider it MY home so I pay them no mind ;-) I even save all my coffee grounds to work into the soil. The three plants that seem to do very well for me (even in this red clay) are Irises, Daylilies and Cannas, but I too am having a lot of difficulty with GRASS. Or the 'lack' of grass. That 12 yds. of 'top soil' that I got turned into a nightmare as it contained a lot of dark grey/black CLAY!!! I have learned that I prefer RED clay over the dark clay. At least you can 'see' it ;-) What else(besides coffee grounds) can I just toss on to help break down this soil? Any help would be much appreciated. Do any of you have web pages/sites from your gardens as you worked on them? Links would be appreciated by me as I feel very much like a pioneer in this endeavor to 'get the best' of virgin/native soil... Here is a link that might be useful: 4th year of winning Red Clay war...

"As for landscape cloth, most people think of it as a barrier to keep things from growing through from underneath, however it's real purpose is to keep weed seeds from rooting into the soil from above." However, most applications of landscape fabric are covered with a mulch. And weed seeds will germinate quite readily in most mulches, which will tend to break down in time to a soil-like texture anyway unless routinely refreshed. And even rock mulches will collect plant debris (unless blown off weekly) that will also provide a base for weed seeds to germinate. So the landscape fabric is really only a very temporary deterrent to weeds appearing. A decently thick layer of mulch will accomplish the same thing and without the potential for weed roots to grow through and get tangled in the cloth/fabric, so far easier to remove If you search these forums and elsewhere online, you will find countless negative reports about the use of landscape fabric. It all boils down to the essential concept that it is more trouble than it is worth and does not effectively stop weed development. Most professionals that do routine landscape maintenance tend to avoid it like the plague. I too have been landscaping professionally for several decades and I only use it as a underlayment for a hardscape installation........and not always then.