Hello! I planted wildflower seed in a small area of my back yard lawn in mid April 2015. Most of the annuals are blooming, some of the mid to late summer bloomers have buds but haven't opened yet.

In having an issue with flopping, especially in the back of the wildflower garden. The front seems to be okay for the most part. The rain and our sprinkler only makes the problem worse. The taller bachelor buttons are flopping... some of the poppies.. some cosmos.. it seems like they are so tall with skinny stems.. the stems aren't supporting their weight. Any idea why this is happening or how to fix it? I bought a delphinium plant and put it in this area.. it's flopping, too! Such a shame. I'm new to gardening so all advice is welcome. Also wondering the proper way to stake plants. Thank you in advance ..