Don't trees plug tiles?

Yes trees do plug tiles.

There are two solutions to the problem. The first is to replace the perforated or clay tile with solid tile through the buffer. The second is to modify the planting design over the tile. This design would include a 6 foot wide zone of cool season grass centered directly over the tile.

On either side of that is a 12 foot strip of native grasses followed by shrubs and trees. While native grass roots grow to great depths they have few lateral roots so backing them off 3 feet from the tile will keep them from plugging it. The key to shrub and tree placement is to keep them as far away from the tile as the mature tree height, as this is the distance their roots will grow.