I have used Miscanthus giganta (Roseau de Chine) - which is one of the tallest growing grasses. Currently it is at about 3m high. You have to plant them fairly compactly (so I staggered them) and I leave them over the winter and cut them mid-Spring. This has worked as a great hedge. At the beginning they don't look so good but as they thicken up they are lovely green in the spring and summer turning to a golden straw over the winter. Non-rampant. This image shows their height but not how pretty they can be. Where I live farmers grow it in fields very close together and it is stunning! http://www.visoflora.com/photos-nature/photo-roseau-de-chine-miscanthus-x-gigant.html

I think the tree and the grass are different dilemmas. I think your tree is one that has leaves that turn purple - there are crab apples with purple leaves - did you have a pink blossom in spring?The straw was probably used to keep the seedlings moist after seeding. Is your grass a St Augustine? Sometimes a bout of cold can turn the leaves purple - either they revert back or go yellow and die. If they start to die call the landscaping company. It is already unusual so worth giving them a call.

I have lots of big trees in my backyard and we have re-sodded the grass 3 times in the last 10 years. So, I have spent a lot of time looking at ideas myself to find a replacement for the grass. We have a very large deck that takes up a lot of the backyard, but the trees have gotten so big that they now block light and the roots compete with the grass. I have been re-doing my yard and we have trimmed the trees to thin out the canopy for more light. But, I LOVE my green trees outside my big windows, so they are staying. I have decided to enlarge the corner bed around one of the big trees and edge with tumbled flagstone all around. This bed has hosta, hydrangea, sweet woodruff and lamium groundcover. They all do well in the shade. In the areas along the fence and where it will not grow I have planted vinca with the purple flowers. I also have two mature clematis vines in locations with some sun that are doing great. I have decided to limit the grass to a smaller area that gets some sun and prep it well and put down sun and shade sod. From looking at your yard, I would suggest a combination of solutions as well. How about enlarging your sitting area with pavers to create more entertaining space and remove a that portion of dead grass. Then pick an area to have a much smaller rectangle or circle of grass that has some sunlight coming through. Really prep the soil with the 4 way type top soil mix before you put new sod down - and buy the sun and shade sod that only needs 2 hours of sunlight. You have to water 3 times a day to help the sod set roots. Plant it in the summer so it has time to set roots before winter. Keep the dogs off it for first two weeks until it starts to grow. That way you have less grass to take care of and water, but in a space the dogs can use. The areas that are just walkway, just mulch around the existing pavers. Regular inexpensive mulch that you can replenish cheaply every year or two with a $4 or $5 bag. I am not a big fan of loose rock because of the all the leaves we have. Too difficult to rake over. Pavers are much more useful than pea gravel.

@keako--finally remembered to snap a picture of the roses for you! It's pouring rain today so it shows up the green of the 2 Ginkos. The Knock-outs are hot-pink, but look red in the pic. The 2 rose trees are a light pink. Below the Ginkos (hard to see) are hot pink dianthus, mauve campanula, and dark blue/purple agapanthus (not blooming yet). Those plants alternate ×2 in the boxes. In other words, 2 boxes are planted the same, 2 are different. The yard is currently a dog's breakfast. We are raising the level of the yard, so don't care about the lawn at the moment. It will be re-done after the addition to the retaining wall is finished. (You can't see it in the pic.) Also, there is currently 1 tonne of boulders sitting there for our water-feature that we are re-doing from scratch. Previously we had a smaller one with river-rock. The old gazebo is a work cover for some painting projects we are working on. It's temporary and will be replaced. We haven't decided with what yet. The other mish-mash of pots is a bunch of Easter lilies waiting for a spot in our front raised beds once those are done and a large tree is lifted and re-planted in them. The strawberries are coming out of their plastic pots and going in a spot in the ground. The empty rounded planting area is a holding area until we re-work the lighting for the water-feature and finish the yard. The saw-horses are for a wood project we are doing, but it's raining today and hubster is under the weather. I will go move those and his garbage can back in. The misc. patio furniture is from an old set. Our new set we just got is waiting to be unpacked from it's box in the garage. Along with new cushions. The golden cedar is leaning because its rock base is no longer level. Also, we are trying to find a spot not in a pot. And that's how the diy stuff is right now, lol. Along with our other big projects elsewhere outside the home (charity stuff). I'm looking forward to the next 2 months when it will be almost all done!! The guys are working on the yard in between their real jobs. And for the moment I am free from hauling loads and buckets of gravel and rocks!P.s. Our yard (and everyone else's) is sloped, and yes the fence is level.