As another gardener growing plants on clay composed of Mississippi River silt, I can tell you that the quickest way to turn things around is to put about a foot deep layer of pure compost on top of your clay and then plant in the compost. This approach combines instant gratification with long term soil improvement. The best of both worlds. I have a long line of those stately old 100+ year old live oak trees lining the front of the yard. I can testify that the 'soil' under those trees was a tangled mass of roots that you about needed a jackhammer to dig in. Now I can just push the soil aside with my hands to get a hole to plant in. The problem is getting your hands on enough compost to do the job right. One big plus in our area is an abundance of sources of all the free compost you care to cart off. Cotton Gins produce mountains of organic waste. (finely shredded cotton hulls, stalks, leaves) If they don't pay someone to haul it off, they would be buried in the stuff. If you show up with a pickup truck, the guys here are happy to grab the front end loader and load you down. Look around your area for a cotton gin and see if they don't have a mountain of free compost for you. It's smelly stuff so water it in well after you put it down, but the combination of compost and clay makes the best soil you can imagine after a couple of years worth of earthworms plowing it up. If you can't get it free, then the next cheapest thing would be to see what the area garden centers charge to deliver compost in bulk. The bagged stuff is way too expensive in comparison. Have fun!

I just bought the biggest plain old terracotta pots they had available at my local big box store. They don't need to be fancy at all. Eventually, the Rudbeckia will get tall enough to hide the pots from view. The more potting soil that fits in the pot, the less often you'll have to water. Adding in some of those water absorbing polymer crystals to the pot before you plant will also save you from having to water the pots as frequently later. If I had it to do over, I might even buy some of those lightweight faux clay pots that don't dry out in the blazing sun quite so fast. Interestingly, when I moved one of my pots, I discovered that over the years the Ruellia had rooted into the ground through the drainage holes. As far as I can tell it hasn't made any attempt to spread out into the surrounding bed through those holes. It just seems to have kept me from needing to water the pots as often. If you want to put down a barrier that will stop Bermuda grass from growing from your neighbor's yard back into your new bed, it's quite a little undertaking. Rosiew has already mentioned digging and leaving a trench around the bed so it can't tunnel it's way underground into the bed without you noticing it growing across the trench. Another option which is a lot of work up front and then less work later is to place a wall underground to act as a barrier to keep the Bermuda grass out. Google for "Bamboo Barrier" and you'll find the sort of durable plastic products you would need to be successful. Thankfully, the shortest, thinnest, cheapest, material sold to be used as a bamboo barrier should be more than sufficient to keep Bermuda grass at bay.

Aimee: You helped me a lot with the own-root vs. Dr. Huey dilemma, so I share with you my experience with a new house's heavy hard clay in Illinois. When our house was built 12 years ago, the builder put less than 10" of hard clay topsoil. I did research on breaking up clay soil: the experts recommend coarse pavers sand (NOT fine playsand). That did it nicely for my 4 white pines. The peat moss works better in your dry climate, and will lower pH by 1 point (1 to 2" of peat moss worked into the top 6"). Michaelg is right: it's easier to add bagged topsoil on top, like Scotts' Premium topsoil with peatmoss. We used a heavy-duty rototiller to work the sand in, and must had hit a limestone and broke the rototiller. Lowe's sells soil kit for $11, but I would find a more accurate separate test for pH alone. I got stuck with a big bag of alfalfa meal from the feed store, and it worked nicely in breaking up heavy clay (it separates soil like peat moss does). We could not use much peat moss in the low part since there's a lot of rain here, but with your dry climate, you can use more to lower the pH and makes your soil holds moisture better.

I have since gotten another Trachycarpus Fortunie, and planted in my native soil and it is doing fine now, I will add some fertilizer along side of the bed before adding mulch for winter, but, I think the new palm is doing better because of me putting it in the ground in "real soil", and the fert doesn't hurt, that's for sure, I just added some fert and some limestone with magnesium in it as a top dressing. I have used a umbrella to shade the new Trachy. Fortun, right after planting it, which I hadn't done for the new 1 right after planting in a pot and putting in full sun. So I know I've babyed the new Trachy. Fortun. well enough, I planted it in the ground, shaded it and provided any nutrients it could need right after planting, and I've watered it about every other day after planting. So I know that the Windmill palm is in the best state it can be. I just need to protect it in winter. I already have info on building shelters for it, so other than some questions for those who have made shelters, care for these palms should be okay now. If someone mentions a certain nutrient they need that i don't know, go for it, but, I did purchase A 'pALM FERT" I DO need to get a "time release palm fert", but the 1 I have now is good to use for now.