Well, I've been thinking about this. I think for lilacs and hydrangeas, you might do better with chopping out the concrete. But many smaller or shallow rooted plants to very well indeed in raised beds and boxes. You can even grow small trees in large boxes.

And boxes means less bending over to tend the plants!

I found this on the Pennsylvania forum! Looks like lilac will do well in a container!

Here is a link that might be useful: Lilac in Container

I also have a concrete pad back yard in Virginia, but much smaller than your place. I'd think that light would be a big factor for you, if I am understanding that you are surrounded by other buildings. For that reason, before you start chopping concrete (a BIG job!), I'd suggest you try container gardening to see what type of plants are successful under the light conditions. (containers are easy to move around!) For example, I've had good luck with a small dogwood tree in a big Oak 1/2 keg. Hydrangeas would be ok in a shady spot -- and they, too, do well in a large container. Lilacs like SUN! Do you have enough? Good luck! Concrete back yards can be fun.

Why bother chopping up the concrete? Maybe consider inexpensive, black plastic container planters. You can buy various sizes....and do clusters of small plants in front of the bigger ones...and totally hide the containers...so all you see are the plants. You can buy them pretty cheaply at Home Depot.

Here is a link that might be useful: Compact Garden

Sounds like my former situation in Philadelphia. Shade and wall aesthetics were my biggest issues in the downstairs 18x18 ft space. I built beds against 3 of the walls using PT 4x4s and 6x6s, filled with compost, sand and perlite or vermiculite. Vines will grow up the walls if you have supports (like lattice). I caution against ivy types that can glue themselves onto your neighbors' walls. Also, perennial vines lose their leaves in winter will need trimming off the utility wires at a minimum once a summer. Containers (incl. a half barrel) and garden furniture for relaxing in the early evening breezes filled the middle.

I have two small patios all concrete...NOW I have a lovely container garden small rock garden small table and two chairs..Sue

Boy, I'd love to see pictures!

Janet's Garden