The cascade have officially hit the top, about 21 feet of twine. Most of the plants are fully burred. Most sites online say to trim the bottom 3-4 feet and I can see why as they don't really produce any burrs. I trimmed the bottom foot of each plant and left the rest considering it is their first year. I also had some mites on one plant but some soapy water seemed to take care of them. I have been meaning to apply one more application of fertilizer that is high in phosphorus as that seems to be what the burrs need to mature into cones.
The centennial have reached about 8 feet and are starting to sprout laterals, although I'm mainly leaving them alone this year so they can grow their roots.