I think it is important NOT to use the terms "naturalized" and "invasive" interchangeably :-) They are not the same. A great many plants have the ability to naturalize or self-sow to some degree yet never become invasive. Certainly a plant that naturalizes wildly or over a large area has invasive potential, yet it is not a valid conclusion to assume it is or even likely to be so. For example, common privet, Ligustrum vulgare, which is most likely the hedge plant referred to above, is not considered invasive - or a defined ecological threat - in many areas of the country. Location and climate play a huge part in any plant's invasive characteristics and what may be considered invasive or potentially invasive in one particular area may be a perfectly well-behaved plant elsewhere. There are other species of ligustrum that offer a much more threatening nature over a far wider area and those should certainly be avoided. But being evergreen, they are far less likely to be successful or even hardy in colder climates and their threat is typically limited to mild winter climate areas. And while I endorse the use of native plants for many cases - localized hardiness and suitability for various climate and soil limitations, attraction for wildlife, native area reclamation - limiting one's gardening choices to only or even primarily native plants is unnecessarily restricting. Many of these are also considered weedy and while not technically "invasive", they are sometimes overly aggressive spreaders also and often not very ornamental. There are huge numbers of non-native or 'exotic' plants that are not the slightest bit aggressive or invasive that add considerable color, interest and ornamental value to our landscapes and should not be discounted simply because they are not a native species.

The pH makes a tremendous difference - you guys are further north then us in Chi town and get colder temps but it sounds like the soil is a bit lighter and the pH is in the correct range. You most likely also have more reliable snow cover then us as well. For us here in N. IL, my feeling is there's too many factors going against to have any notable success with azaleas & rhodies even the 'Northern Lights' series. The soil in general is very heavy black clay except along the very edge of Lake Michigan and certain other isolated pockets; it tends to be wet and gummy over the winter (a plant killer), along with unreliable snow cover (which is an insulator) and add to that a high pH and the added stress of cold temperatures usually results in near failure or marginal success. For Virtuosity, I've seen your place over in the Design forum - a new subdivision probably means you have not much in the way of topsoil so I'd recommend skipping some of these so called bargains from the box stores and taking a trip down in the spring to Natural Gardens for some colorful tough native shrubs or good cultivars. You'll pay more but you'll come away with expert advice from the staff and plants that will work for you in your environment. Limestone bedrock occurs naturally in many areas under the subsoil in N. IL and no amount of ammendments is going to permanently alter the existing pH to any significant degree.

Do not worry about Oleanders toxicity. my aunt has been a veterinarian in PHX for 30 years and has never seen or heard of a case of oleander poisoning. We decided against Oleanders because of the proximity to the pool, they are very messy. We instead planted a Japanese Privet hedge, total of 65 5-gal spaced 3 ft. The only main drawback is the water consumption during their first summer. Each received 5 gallons of water 5x/week. Heavy water schedule on a reliable drip is an absolute must in their first summer. Otherwise they will fry. Even with consistent deep watering, about 20% did not survive. Another tip that will greatly enhance survival and thrive is proper soil amendment. Privets do not like high PH soil (too much salt) which is very prevalent in AZ soil. Prior to planting, treat the soil w a sulfur product. this will loosen the soil and allow for maximum nutrition uptake. Ensure to continually treat the plants w products that will lower PH levels. Many synthetic fertilizers will increase PH, so look for a local organic compound meant for trees and shrubs. Our hedge has grown 4 ft in 2 years. and will grow faster now that they're established. Good luck!

'Puget Blue' was selected at the Seattle arboretum sometime prior to 1945. It is thought to have been grown from seed of Ceanothus papillosus sent by Lester Rowntree (of California). A plant labeled 'Puget Blue' grew for years at the entrance to the old arboretum offices, however the late J.A. Witt (arboretum curator) felt that this specimen was not the true item. So stock originating with people helping themselves to cuttings of this prominently located plant may have been circulated erroneously as 'Puget Blue' in the past. The original 'Puget Blue' may have been selected, grown for a time at the arboretum and then lost (to the arboretum) decades before the one at the offices was present. I bought C. thyrsiflorus 'Oregon Mist' recently, it originates with Xera Plants wholesale nursery in Oregon. From their web site: Very odd that a genus cherished in California and Europe- with many native representatives in Oregon has NO selections made from this state. WeâÂÂve decided to change that by selecting a form of Blueblossom from near its northern native limit. From Coos County we chose this variety for its deep green leaves and striking turquoise blue flowers. Large growing evergreen shrub that should provide superior cold hardiness. Also, it is a great representative of this species in the wild. We took cuttings of this plant where it grew simultaneously with a salmon flowered variety of Rhododendron occidentalis inbetween California Bay (Umbelluaria) and blue flowered Iris douglasiana. Interesting that this shrub grew in heavy clay soil where running water flows during winter. To 8â tall and as wide very quickly. May grow larger in optimum conditions, tip prune to limit size, increase density and blooming wood. Flowers late April to late May. Excellent shrub for low water native gardens. Underplant with Pacific Coast Iris which bloom concurrently and have the same cultural requirements. May also be used as a small garden tree Most of the interesting dry climate shrubs and related items appearing at local garden centers in recent years are being supplied by Xera Plants. See their web site for photos and descriptions. Note that the hardiness zone designations they make are too optimistic, as is often the case with commercial sources. As with other nurseries if you add a zone to the one they give you will often be closer to the true picture. This post was edited by bboy on Thu, Mar 28, 13 at 15:19