Hi Jodie, A couple of thoughts. First, please take it easy doing this kind of work in summer. Drink alot of liquids and take breaks. Stay cool. It may be the angle of the photos but I hate to say that the bed area looks too small for the scale of those trees. You may want to come out further around the outer perimeter to make the whole garden look more in scale. Stand way back and take a good look. This may be the time to just work on gradual grass removal and putting down some compost and mulch. Then in fall, you could plant some plants. Fall is the best time for the South, usually. You could take this time to study the sun and shade patterns, drainage, etc. It looks very shady there, however, it may be sunny most of the day or have enough sun due to the high branches and the zone you are in. Also are the trees evergreen or deciduous, if oaks they are virtually evergreen. The plants you will need will be different depending on sun/shade, moist/dry conditions, and whether you can or want to water frequently if the plants you choose need that. It is so exciting to put in a garden, and you are probably very anxious to get it done now that you've started, but I hope you will consider some of my suggestions before going too fast. You might then have to move a bunch of plants or lose them. Also you have to consider covering the tree roots with too much mulch, I think 2-4 inches would be the max, but don't quote me on that. Luckily, you have a wealth of info on plants for DFW on the internet once you know the conditions.

Thank you so much Louisianagal. I will wait until fall to plant. I also need to consider the cost of planting such a large area, and cost is definitley a factor. Do you have any suggestions on how I could make it smaller? Yes, my trees are oaks. I really want to work on the scale of this and do it right for my budget.

Louisianagirl is right about the size of the bed. It looks to small for the size of trees. Maybe you don't want to enclose all the trees in one bed if you are looking at costs. The multiple stems can remain outside of the bed, the shadiest part and just make the bed in the sunnier part because trees will be in competition for nutrients with whatever you plant and against the property line? you might want to consider woodies instead of perennials, like azalea or rhodys to set a backdrop for perennials. I have linked a blog for you to chose perennials and their propagation to cut costs further by leaching divisions from family and friends.

Here is a link that might be useful: Propagating Perennials

maybe I could make the bed in the sunniest spot without enclosing the trees? I have been taking notes on the sunny spot throughout the day. The tree guys left me a huge pile of wood/vine chips, would it be ok to spread that out until the fall while I work on a plan. Bullthistle, when you say a backdrop of azaleas where exactly would I put them? I will be checking out Propagating Perennials. I love azaleas. You guys don't know how much I appreciate the help..thanks again

Pleeeeze don't disturb much soil under the Oak trees...they can be severly injured if disturbed too much. Nothing really grows well this close to trunks anyway...the tree roots strangle the plants and steal all the water...you're fighting a losing battle. (I have a small area under a maple tree that I want planted. Every two years I remove the hostas/perennials, dig out all the roots and replant...what fun!) I'd remove the trim, mulch, put some comfy chairs there or hammock, bring in pots of impatiens, hostas (they survive in pots overwinter quite well) and enjoy the shade...while looking at a sunnier, successful garden lol! Here's some info on planting under oaks....Also, don't know if you have done this or would have but never ever add soil on top of the existing grade within 10 feet of a trunk. It will kill the tree....even 4-6" can do it.

Here is a link that might be useful: planting under oaks

Also hummingbirds and butterflies are only in full sun gardens....never shade. Google for the plants that they love....it is fun!

thanks to all of you for the information. Thank goodness I have not moved any soil under the trees. I understand now the importance of not planting under the oaks. I love love those trees. I definitely need to do more thinking and more planning. Whew, I am so glad I finally had the courage to post here even though I don't know a thing about gardening. I will keep you guys in the loop when I decide what to do.
Jodie