I’ve a red oak and a tulip tree in the middle of small, midtown lawns. The oak faces west and was planted by the City of Toronto in the front yard, 5-6 years ago. The tulip tree we planted, in the back yard about 14 years ago. To date, we’ve kept a small circle of open soil at the base of both trees. I’m wondering if we should maintain this practice or whether we can/should let the grass grow right to the tree’s base, or if we can/should consider alternative planting, and if so might you have any good suggestions. I’d be happy to remove/reduce the grass, particularly in the front but don’t know what would grow well under the oak which now pretty much shades the entire area.
Thanks for your expertise!
Look first at the overall garden and its design and plantings. Do you want or need low-growing shade perennials under either tree? Does the area look sparse compared to the rest of the garden, or is the tree in each case a feature all on its own?
I would not recommend grass right up to the trunk , as there is always a danger of trimmer or mower damaging the bark if you accidentally get too close. You could try mulch if the season does become drier, or the heavy oak does not permit rain to keep that open soil hydrated. You could use the bark nuggets under trees.
If you wish to have low plantings, consider ferns and/or hostas, which will tolerate dense shade. As oaks do well with a water level close to their top roots, ferns would flourish. Consider weaving a soaker hose among the plants, and water weekly if there is not a lot of rain.
As with any tree, be careful about the tree’s needs first, and the concerns about adding too much topsoil for the plantings you choose to add underneath. You do not want to cover any roots exposed. Oaks are good in that their roots are not near the surface.
Here is one article that clarifies this concern.
When you search planting under oak trees you will find other advice.