That spot would be death to a hydrangea, and probably a lot of other things. A 3 foot cutout isn't very big for a plant/tree of any size once the roots start to spread out. So you might want to rethink what you want to use that spot for. Try googling "tough street trees" for ideas.

Larry

Thanks for the input!
On second notice (now that we've had a few sunny days in a row), it appears the spot doesn't get sun all day like I thought it would. Mostly late afternoon/evening sun (there were other parts of my patio area that get it all day).

Anyway some people at the nursery recommended rose of sharon and the limelight (it's a hydrangea that actually likes the sun!) because they said the root structure wouldn't be invasive at all, and if we kept them pruned short, they shouldn't go too crazy.

I don't know... we are still evaluating :)

Thanks!

Both hydrangea and Rose of Sharon would be quite ugly focal points in winter. Think aout an evergreen shrub or grasses (miscanthus) which would look good year round. Or just plant annuals in there for summer and clean up in fall.

I would first try to dig a hole to see how compacted the soil is in the area you want to plant. If it is compacted (due to the installation of the patio), that would be your first thing to consider when selecting plants - what plants grow in that kind of soil you find- how well does it drain.
Next when do you spend the most time in that area. If you dont go out there much in winter, the hydrangae (summer blooming) would be ok It is not the nices looking winter display! But if you not out there ! - The tree form of that hydrangae ie - Limelight would put on a good display in summer and you could plant some annuals around the base.
Conifers like a weeping white spruce would fit the spot, however it would get tall.

Consider making a container out of the block that you used for the patio - open at bottom, elevated about 3ft - filed with great planting mix, then plant unusual annuals with big leaves , some hanging plants and interesting colors. Each year you can make it different. Or -- You could even plant a small flowering tree and now the roots would have a little mor room

Have a good time planning

Mike

Maybe a Windmill Palm (Trachycarpus Fortunei)?