bboy, the information I provided indicated certain strains of buddleia will survive zone 4. That's not my opinion, it's information about them from those who know. The best advice is always to consult with a reliable local nursery/horticulturalist before purchasing/planting. I disagree with your opinion that fertilizer spikes are an ineffective and expensive way to fertilize buddleia. Possibly where you are? Certainly not here. It depends what you want,I guess. We want - and now have - a 20' tall, full, reliable screen that produces countless deep purple 1-foot-plus-long blooms all season and is also a hummingbird and butterfly magnet. In the wild (without fertilizing) they look weed-like with sparse, small blooms. Considering the fertilizer spikes we use are 20 cents apiece (we use five of them) and we have a 100% privacy screen covered in blooms to block an unsightly yard across the road, I don't feel that is either expensive or ineffective. BTW, we live rurally and the specimens I'm talking about were dug up for free(with the owner's permission) from a lot about to be bulldozed to build a house. They grow wild here and we like to naturalize as much as possible . I wouldn't dream of putting them in my rose garden or other more cultivated areas. As a perimeter screen, they have worked perfectly. I guess what constitutes a "pest" is in the eye of the beholder. Best wishes, Sue

What about a Bradford Pear Tree, Vitex Trees, Crape Myrtles, Robinson Crabapples, Southern Magnolias, Powder puffs (mimosa, Royal Empress', pink dogwoods or cherokee chief (beware of the diseases it can obtain) and lastly the one featured as #1 in DC Cherry festival, the Yoshino Tree ( I reccomend this )

If in western WA, I'd add Doug fir to the mix as well. Grows like a weed in much of the area and rather rapidly at that. It can certainly become sparse and bare at the base over time but it's hard to ignore the native species for very adaptable and tough trees suited to this location and it mixes well with the others to create a very natural looking screen. Not as tolerant of wet soil conditions as the cedar. Local DNR and native plant nurseries often offer these as seedlings at very inexpensive costs for reforestation and woodland landscaping projects. Worth checking out.

i agree with jakkom. Rhamnus "John Edwards" trained as a column from 5 gallon can, will grow quite fast. Acca sellowiana Pineapple Guava, especially if you buy it already trained as a standard . I have Prunus compacta as well, and it was been much slower growing than rhamnus. Pittosporum heterophyllum, or tobira. Arbutus grows slow unless you start with specimen sizes, you might be waiting for screening for a while. If you are willing to wait, there is also manzanita, arctostaphylos "Dr. Hurd."