Mow grassy areas, use glyphosate (Roundup) in non-grassed clear areas, and hand pull the few that come up right beside other plants as soon as they are noticed.

"We also learned that the potting mix the JM's arrived in was heavy on the bark side.This is commonplace with all growers and grafters of JM's. It ROTS within 6-12 months, so the bark must be removed from the JM's whenever you up-pot...... Remember this: Growers don't ship plants with sustainable soil. It only lasts 6 months." I am going to disagree with this :-) While I don't do it commercially, I grow all my JM's in containers and have for many years.......my oldest is approaching 30 y.o. And my potting mix is and has always been heavily barked-based as it produces a very freely draining, textural and extremely durable media. With this barked based mix (the 5-1-1 discussed intensively on the Container Gardening forum), I do not need to repot or refresh the soil for 3-5 years depending on the container and the size of the tree. Even at that point the soil is still in reasonably good condition. The location and depth of the perched water table is entirely dependent on the soil media being used, not the size/depth of the container. It is quite possible to maintain a small seedling or 1 year graft in a 4" pot or a larger, 7" deep trade gallon for as long as necessary before up-potting provided you are using a highly textural soil that allows for fast drainage. Due to the vagaries of soil physics and water movement, there will always be a PWT in the base of the container but the better the potting mix, the lower/thinner the PWT will be. The reason growers focus on bark-based mixes is for this very reason. They hold up well long term yet provide the aeration and very necessary fast drainage but the degree of moisture retention JM's are happiest in. And also maintain a low PWT. Although it would not be my first choice, your perlite based mix should offer a similar situation. However, I would encourage you to disavow yourself of the notion that a barked based potting mix deteriorates rapidly. 30+ years of using it and growing a large collection of containerized trees (a variety but primarily JM's) has adequately proven that to be inaccurate :-) I would also encourage you to read this thread on container soils and water movement thoroughly to educate yourself on the many qualities of a bark-based mix.

I know this is an old thread, but I came across it today because my lawn is covered in thousands of tiny maple tree sprouts. I have a large lawn (about 1.5 acres), and I am wondering if I were to "quarantine off" a section of the lawn far from the house to not be mowed, what is the chance that any of the maple seedlings would survive? This seems unlikely, but my wife I thought it would be pretty cool to allow a section to become forested with these maple trees. Does anyone have a ranging guess as to how many might survive in a 100' x 75' section if the ground is covered with trees? I live in northeast TN. Thank you for any wisdom/thoughts!

Barring creative chemistry, you can dig them out or simply mow them down (I'm not sure how mowable your incline is) and keep mowing them down if they re-sprout. Which they probably won't, but with hundreds somebody's going to manage. If limited creative chemistry is OK, put on latex gloves. Wet a sponge in Round Up and go swipe the sponge on the maple leaves. You'll use a minimal amount and still kill the tree (we tend to over-use the stuff, it really only takes enough to make the leaf shiny). With that small an amount, you will need to hit every leaf on the tree to assure that enough gets absorbed to kill it. And a few will survive and need to be done a second time.