Shrubs will establish best in the cool, wet weather of spring. Frost has no meaning for them unless, as the previous poster mentioned, they have not been hardened off or have been shipped from a more southern zone and the leaves are way ahead of where they would be if they had been growing in your zone. I still would put them out and protect them if you have frost. As for perennials, I (zone 5b) start dividing them in late April and through March as soon as I can see them. If they're up, they're ready for it.

Thanks for the help Dan. One other question, I need help with. Since in the past I have seem a lot of propagating failure at the point just after I have managed to get my cuttings to root. So since my Mahonia cuttings will need to be cut this fall from this years growing season's hardened off wood, and since they will have been so difficut to root; could anyone please advise me on how to mix up the potting soil I will need to prepare for planting any of the cuttings that sprout? Also, if the answer to that is a soil-less mixture like periolite or something else similar, How will I know when they will needed to be transplanted into regular potting soil? Or would it be better not to transplant them into potting soil, but instead to simply plant them outside in a southern facing landscape bed?

The funny thing is that several large reputable nurseries advertise the height and spread at 4'. Bailies Nursery says 3'-4' mature height! McKay Nusery says 4' mature height and spread! Its just crazy that I planted them last spring and they were maybe 2ft tall. Now they are 5ft tall, caliper of stems went from pencil thick to 1" thick.

why dont you mail order them???? ... see link .. btw.. you are talking about conifers.. not shrubs ... anyway .... obviously.. for $3.50 you are going SMALL!!!! call girards ..... and see how much bigger they can mail and still be price efficient ... and.. keep in mind... EVERY conifer has an annual growth rate ... and most.. will continue to grow at that rate forever .... w/o researching.. i am going to guess this one is about 3 to 6 inches per year... MOST SIZE ESTIMATES ARE AT 10 YEARS .... and from 10 years on.. they will continue to grow at the annual rate ... [or... divide 3 feet (your est.) .. 36 inches by 10 years.. and your growth rate is about 3.6 inches per year .. go figure on that .. lol ] so its a matter of what size you buy them.. how well they prosper [might be questionable at a school] .. and how fast you can run away from the project.. lol ... i bet.. even with shipping.. you can mail order cheaper than buying local ... good luck ken PS: note that they have a secondary name for the plant at the link ... so search both names Here is a link that might be useful: link