Gardening has two branches, the fruiting
and the decorative, so I don't know which you are aiming for. Assuming
the fruity type, one thing that's coming is the super-hot weather and
with that a general (but not total or inescapable) pollen death, and so
keep in mind that there are varieties of plants that fruit without
pollination. Also a smaller plot like a 4 X 4 won't self-shade well, so
you might need to add some somehow if you have plants that can't take
the direct sun..

One quirk about Az: there are many best guesses about last frost
date, and NOAA's is the beginning of April! Tucson got NO frost after
the beginning of January, so if you follow the common wisdom you'd be
running as much as three months late. It often pays to not listen to too
much advice about timing. Of course that could also come right back at
you and bite bad. When it works, you get to do this in April...

Thank u for your advice! Might have helped if I said what I would like to grow! The answer is anything edible, or beautiful! Prefer edible. My family loves all vegetables so my options are endless in that regard. The picture you teased me with makes me even more determined to learn! Are there any vegetables worth planting right now? Any other time I would have loved this, but my backyard has one small area that isn't shaded by other houses and it's right where I wanted to put my garden so it gets enough sun. And shading the area won't be hard because it's up against a fence. Thank u for your help!

melons, but they take up a lot of space, same with watermelon, Armenian cucumber which is really a melon, okra, corn, eggplant, yard long beans, squash etc. tomatoes will have a tough time as far as pollination when the temps get up to 100.

Here's a link to the UofA master garden calendar. It gives you a good idea of what to plant for your elevation. Its getting to be too late for much of anything in the valley, definitely too late for tomatoes, but at least you'll be ready in the fall. Almost anything you do plant will benefit from a shade cover when it heats up.

http://ag.arizona.edu/pubs/garden/mg/vegetable/regions13.html

Thank u for all the advice!