I meant to say copperleaf. Dave's Garden says that Irish petticoats and Hoffmannii are one in the same. Curly Ruffle might be another name for it too.

Makes perfect sense, Zoom. I'm going on about a more specific meaning for the word "invasive", one which actually has little to do with whether or not a plant grows aggressively, has rhizomatous roots, or what have you. In this usage, it's all about whether the plant in question is or is not native to a given area. So, a very agressive, fast-growing, but native plant, in this conception would never be "invasive", simply because it's "from there", so to speak. Don't worry, I've got little side-arguments all over the web about the use of the term. If it seemed like I was teeing up on you, I didn't intend that. So, in this conception, the issue you seek to know about is whether or not the plant is aggressive. It may or may not be invasive. Good luck! +oM

I live in zone 5, Maine. I'm focusing on flowering native shrubs: Kalmia (Mt. Laurel), native evergreen rhodos, and blueberries. Possibles on my list are a dwarf redbud or a dogwood, clethra Ruby spice and Baptisia. The garden that came with the house has a bunch of lilacs and hydrangeas, a magnificent magnolia and a lovely crabapple. Many of those should work for Colorado and many Maine natives will also be native in CO. You want to check your soil type. When I moved, it wasn't a huge difference of climate, but the soil changed from damp, alkaline clay to acidic soil that is very fast draining. That's one reason for choosing natives --- they are probably going to like your soil. I had to change some of my gardening practices, too. If you make a big move (mine was from a different continent) you discover that many gardening "facts" are actually rules of thumb that work for the climate and soil where they originated and often explanations are based on that. I tried to grow spinach, always called a cool weather crop that bolts in summer heat, outside of Moscow, where the summers were cool. It barely grew and then bolted overnight. It turns out that it bolts when the days get long and so far north, the days got long too quickly.

If you don't want anything to grow taller than 10', you are looking at shrubs, not trees. And there are a fair number of shrubs that will easily exceed 10' as well, so you might need to prepare yourself for some pruning down the road :-) CA has an amazing array of native plants that could work, including a bunch of appealing flowering shrubs - ceanothus, manzanitas, flannelbush, Carpenteria, salvias, etc. A visit to a good local independent nursery would expand your choices significantly. The planting bed depth will need to be sufficient to accommodate the full mature spread of the plants being used plus some wiggle room. If the shrub grows to be 8' wide, than you need at least 8' plus.....so 9-10'