Deadhead, deadhead, deadhead. That's the best thing you can do to keep any plant growing and looking it's best. If you haven't fertilized do so a week before the show, so you have nice green plants. With hanging baskets trim out any branches that have bare spots, but don't trim too much--two weeks is not a lot of time for them to put out new growth. If you are cutting stems of flowers for show, gather them in the morning when they are plump from the cooler night. Choose one that has nice looking leaves as well as the flower. Cut the stem longer than you'd like, then trim the stem again inside under running water, and put it immediately in your vase of water. Make sure there are no leaves in the water. Just my opinion as I've never been in a flower show, but it's what I would do if I were

You can grow most all annual flowers with the right soil mix. Keep in mind that some plants just don't like our salty soils, salty water, high heat and low humidity. Most of us have used the 'trial and error' method to find the varieties that survive in our planting areas. 1) Your goal is to create a bed that is about 12 inches deep. First, moisten the area well by letting a garden hose trickle for several hours or overnight. Wait 4 - 5 days before digging. You'll want soil that is moist but doesn't stick to your shovel. A great recipe for garden soil is 1/3 native soil, 1/3 compost or composted mulch and 1/3 pumice, coarse sand or perlite/vermiculite. Our clay soils hold moisture but tend to be 'tight' and can restrict water and air - hence the compost and sand/pumice. 2) Till the area with a shovel or garden fork - or you may want to use a rototiller. Add a 4 inch layer of compost/mulch and 4 inches of sand/pumice. Till again. This will give you your 12 inch garden depth. 3) You can add amendments like ammonium phosphate or ammonium sulfate before you till. 4) When you are done tilling, the garden bed area will be higher than the surrounding soil so you may want to use a border of some kind. There are dozens of choices from the standard concrete blocks to more decorative stones, wood or even PVC. 5) To water your beds I'd recommend the 1/4 inch tubing that has emitters built in. Each emitter puts out 1/2 gallon of water per hour and they are spaced either every 6 inches or 12 inches depending on the brand. I'd discourage the use of microsprays because much is lost to evaporation. I'm sure others in the forum will have more ideas for you. Here's a link to a guide on what to plant and when. Good luck. Here is a link that might be useful: Flower planting guide

That kind of mulch is nice, even to till in with dirt. I do it all the time now. (Assuming you're talking about the shredded hardwood mulch.) You'd be surprised, next spring, how much that mulch has composted anyway! Add some compost along with it. Another idea--I've also tried putting cardboard underneath mulch and compost, and even under a couple of inches, the cardboard is gone in about 3 months--worms love it, it just composts away. That would help the weeds. Other people can probably help with bed-making but also have you considered planting something in the fall that grows through the winter? If you're thinking of veggies, you can do some kind of green-cover or if it's ornamentals, there are lots that look great all winter and don't need much care.

If you have nothing on the bed yet, Then cover area with cardboard. Throw 4-6" of soil on top and plant away. Top it with 2" of mulch and apply same amount of mulch yearly to suffocate most (not all) weeds. Cardboard is an organic weed barrier of sorts, cardboard disintegrates and becomes part of soil.You can get free boxes at WM or ant store that recycles their boxes. The stronger wild onions will eventually poke through but it will be a fraction of what you are facing now.