That would be an excellent way to kill your trees. DO NOT BURY SURFACE ROOTS. They're roots, not your knickers. The tree really doesn't mind -- and in fact probably prefers -- that they're exposed.

Tree rings are widely derided in landscape design circles (I think the Renegade Gardener does a send-up) but embraced by many ordinary people whose objective is to make their yard look nice as opposed to achieving a certain design standard for the big picture. I have to say that my reaction to them varies, in that there are some very ridiculous looking exemplars, others where I have to drop my snobbery and also say, gosh, that's pretty. And I mean, it isn't always obvious what else you can do to make a tree grow attractively out of a lawn, independent of whether the tree is well chosen for the site or well placed on the lot - either you can't mow right up to the trunk so you have unmowed grass and weeds, or the roots/tree debris cause an uneven and sickly bare patch under the canopy. So yes, the rings often do look neat and beautiful. I think your circle will be fine for the tree. I doubt the amount of foot traffic you describe will affect the tree. I suspect too that the roots will grow further down into the ground than the one layer of brick, and if they do encounter that obstacle, they will grow under it (if you have plastic or landscape fabric, which you should not have, the roots will stay closer to the surface in a desperate quest for water, and will lift the brick - this may happen anyway if it is a very surface-rooted tree). Mostly, your roots will go down far enough to be undisturbed, and a five foot circle certainly gives the tree enough room to compensate a bit for any excess trampling that does occur outside the circle. Just keep an eye on your tree and see if it looks happy and healthy. Trees have ways of letting you know if the conditions aren't right - you just have to train yourself to recognize what they are telling you. KarinL

i recently built a dry stack circular stone wall around a large pin oak in my yard the wall is 32 inches at its highest point. I am worried about the roots of the oak pushing upward on the wall and destroying it, although i did do some intense labor around the areas where the roots were the most visible. I purposely postioned the rocks in these areas in such positions that there is room for the roots to grow before touching the stones........... time will tell.

There is one more item to be aware of. Many landscape trees are grafted onto a rootstock. Where this graft was done, there is typically a swollen portion of the trunk which can be mistaken for the root flare. If this mistake is made, the root flare will still be buried too deep. We've had B&B trees come in that had as much as twelve inches of soil piled up on top of the root flare. Some times, roots have grown into this soil and need to be removed when planting, again so that correct depth is achieved. Truth is, I'm really tired of B&B trees. All you're really buying is some dirt from the nursery. There aren't more roots retained when trees are handled this way. Usually fewer, actually. One advantage though, is the ability to plant B&B stock throughout the growing season rather than just when the tree is dormant, as is the case with bare root stock. In all other respects though, I believe bare root to be a better choice when available. And yes, tis true that most of our beloved conifers are only available in B&B or potted, with the exception of seedlings. +oM