I promise you that you don't have enough supports under the stairs. They are going to sag.

If the step treads are 2X6, then the maximum span is 24" for the supports.

What will sag??

I would fill in the space between the deck and the yard with lattice so that it looks like it is part of the yard. Then you could plant perennials. Whatever you plant, be mindful of how tall it will get. If you like to look out onto your yard from your deck, you'll want to be sure that whatever you plant doesn't get taller than the deck.

I prefer the wood slats running verticals then lattice. There are a ton of pics in Houzz show different designs. I would run it under the stairs as well so your home looks finished off.

if you close in your deck with boards or lattice, consider building in doors to take advantage of all that wonderful under deck storage area, purchase large rubber bins to hold seasonal items.....gardening, outdoor pillows, toys, etc, just make sure you get ones with tight fitting lids.

@beverly thanks for the vision look!! I love that!!! How did u do it?

I'm not crazy about the lattice work.. We have underpinning that we are waning to finish under the deck that matches the underpinning of house.

I just cut and paste in Microsoft Paint.

I'm not done but I planted 2 gardenia bushes and in the middle is the crepe myrtle