Hmmmm (rubbing hands together). Now, that's a bit of a challenge. Not much space, not much light, not much money, and not a lot of gardening experience -- and it will be winter for at least part of the time. I love it!

I can imagine that being a nice little place to sit in the evening, a cool breeze but with a lot of privacy. This isn't actually below ground level, is it?

I'd definitely get rid of the AstroTurf. That stuff only works in a dry, sunny area outdoors, and it doesn't look like this space is either. Does the ground drain away thru the fence at the back of the picture? Hope so, 'cuz I know it rains a lot in the spring in that part of Michigan.

I assume it's soil underneath, but probably not very good soil for growing. You could lay down several bags of mulch -- pine back is pretty cheap and it's less prone to funky-looking molds than the hardwood. Look for stuff that comes in fairly small pieces, not the nuggets.

Lay down some concrete 24" x 24" pavers, maybe 4-6, in the foreground, against the building on the left, and put out a little bistro table with 2 chairs. You can buy sets pretty cheap, or you can put together something from thrift store finds. A can or two of spray paint and -- voila! -- you have a set.

You don't want to mess around with planting stuff in the ground -- focus on containers. For cheap, big planters, you can't beat big plastic totes from the Big Box stores. (I'm talking about the 35-50 gallon Rubbermaid jobies that are 3-4' long and about 2 1/2' tall. Around here, those go for a little over $20.) You can raise them up on some cinderblocks if you like, and you can dress them up with a wood surround made form old pallets. I'd put two of them along the wall on the right, facing into the apartment, and another perpendicular to the wall on the left, marking the end of the space.

Keep an eye out for smaller containers you can group around the base of the tubs. And keep your mind open -- do a search on creative planter ideas nd you'll be amazed what you can plant in!

Don't forget the walls! You can place lattice panels behind the tubs, to encourage vines. A can of spray paint in a bright color makes them a focal point even in the winter. An outdoor mirror (plastic, not glass) would also add some life and movement.

For plants -- think shady, understory things. Varigated leaves, rather than bright flowers. Coleus, hosta's, ferns. Shady groundcovers like ajuga or creeping jenny spread fast and look nice as a background for other plants.

It's a daunting space, but I think it's great your brother is thinking about spreading out and taking advantage of it. I'm sure you'll make it great!

Lot of good suggestions above.

Definitely get rid of the moldy astro-turf! Agree with container plants too, just choose evergreen shrubs that can withstand snow.

You might want to start a Houzz.com Ideabook (or Pinterest Board) to collect possible inspiring photos.

This article on Houzz might give you some additional ideas:

Spring Patio Spiff-Ups: 12 Doable DIY Projects for Your Outdoor Space

https://www.houzz.com/magazine/spring-patio-spiff-ups-12-doable-diy-projects-for-your-outdoor-space-stsetivw-vs~9000069-Patio-Spiff-Ups--12-Doable-DIY-Projects-for-Your-Outdoor-Space

Alison - Thank you so much for all of that wonderful information! I wish I could answer your questions, but unfortunately I've only been there once and we won't have the keys until a little later. I know that the space may be about 1/4 beneath ground level, but I don't know if the soil drains well or not. That being said, your ideas are more helpful than you know, and we will definitely be taking your advice!

DJ - Thanks for the great links! I think those will be very helpful to both of us. I'm heading over to houzz.com right now to sign up!

We really appreciate your help!

-caseyface (& Jamie)