I love your space and would have a great time planting it.* I have little dogs and wouldn't put in grass. I'd figure out where and when shade is needed and plant one or two small trees right there. Then I'd put a flowering vine on another wall to make a nice background. Then I'd fill in with sturdy 3-5' tall and wide shrubs, grasses and perennials that would visually fill the space but allow space for the dogs to move around. Last, rock mulch. I just use cheap 1-2" fill, no fancy colors.

Avoid anything poisonous like cycads and grasses that have dangerous seeds like my favorite Stipa that is only allowed in the front yard where dogs cannot get to it. Thorns too, Bucky pounced and got a Bougainvillea thorn deep in his foot last week.

*10 years ago after my beloved almond tree died I did design just such a garden. Double foreground of southern sword fern and peter pan agapanthus with saucer magnolia as the tree and various good sized shrubs/perennials that needed homes filling in in a 10x20' bed. Theme was dinosaur garden and hiding in the ferns is a ceramic pea green 3' tall brontosaurus that was a gift from dear FIL. I picked out the rock mulch that was there and replaced it. Now I'm in a very dry climate but even so there's never been any mud coming in the house.

You really do not have room for multiple trees. I made that mistake in my tiny yard as well and had to spend money ripping them out.

Right, more a multi trunk planting of something small, something that can even be grown as a shrub. My magnolia is 15' tall and 10' wide after 10 years. It's a smaller variety than the lavender ones that grow 20x20'. If it hadn't been for that ceramic dinosaur I would have put in a couple crepe myrtles in a 3-4' circle. Other small trees in my yard are redbud and toyon. Redbud could work but not toyon, grows fast and doesn't prune very nicely. If the tree is small then it's easy to cut out tall branches at crotches to keep it natural looking and reduced in size. I've just cut out branches extending directly over the patio so far. For years we needed 2 umbrellas on the patio but need only one on the south facing patio.

I hope the wide part of the yard is facing west or south as there isn't room on the narrow side to plant a tree.

Some kind of this idea

Douglass · More Info

Here is nice idea of backyard plan, you can do partially it

LoHi Private Residence · More Info

Here is nice idea too for your backyard .You can have grass instead of gravel

576 15th Avenue · More Info