"What! How come there are no zone maps in this catalog?"
It is our feeling that zone information does more harm than good. Most of the things in this catalog are hardy, but that word means different things to different people. Although I do make mention of zonal information, it is scattered throughout the descriptions, not etched in stone next to the name. Hardiness zones are more like speed limits, which most drivers ignore to a greater or lesser extent depending on conditions. Most of what is in print is wrong, and we would rather not perpetuate misinformation.
We mostly look at a plants range in the wild and the altitudes that it occurs in and draw our own conclusions. We also tend to be a bit optimistic, and if there seems like any chance, we try it and see. Look at the number of winter hardy things from South Africa and the southeastern U.S. and warmer regions of China. A number of the very high altitude species winter fine but melt in our summers. Some plants from very cold regions live under a thick blanket of snow in the winter and do poorly with little snow cover and winter rains.
Placement in the garden makes a great difference as well. Some plants will winter fine in one spot but move them a few hundred feet and they die. You need to understand the microclimates in your garden to be successful with some of the tricky ones.
To be successful you often need a few plants to experiment with. Don't give up on the first try. "Been There - Killed That"-- words to live by from Dan Hinkley, who I suspect has killed his share like all the rest of us. Indeed the only way to tell who's best among the elite growers is who has killed the most plants. Around here Dick Punnett leads the race but Fred Case, Betty Blake, Tony Reznicek, Harry Elkins, and Jim Briggs and several others all run close seconds. We're probably dead last but closing fast after the last couple of winters. We ought to have "Been There - Killed That" T-shirts printed for the real master gardeners.
If you are having trouble with a plant, talk to other good growers in your area and see what they grow and how they do it. But don't take their word as gospel. I'm always amazed when good growers come to the nursery, see a plant and insist that they can't grow it in their garden, especially when it seems easy here. On the other hand, it's always amazing to see what treasures are to be found in the Punnett or Case or Reznicek gardens that I was convinced could never be grown around here.
Punnett used to be a purist and would only grow it if it would survive without protection (a very long list) but lately he is fussing over a few treasures and even muttering about a small greenhouse. If it won't survive outside and you really want to grow it, put it under poly. Small polyhouses are cheap to build and heat. Any way you slice it, Tree Ferns and Cycads just don't stand much of a chance in outside Montana. Our best advice to those in denial is to move south or build a bigggg polyhouse.
After a while you develop a sense of what is likely to be hardy, based primarily on where it comes from and what it's related to. Actually, some people never seem to, they insist on trying to grow things that are just plain impossible (to give them their due, they do occasionally find something that is much hardier than anyone ever supposed). A garden of nothing but dead and dieback plants doesn't do much for us. It's important to integrate the plants properly in the landscape and camouflage plants that come out of winter looking a little beat up. Also, be sure to remove all signs of their dead bodies and give them an unmarked grave. (We are talking plants here, not humans. Real corpses in the garden are a whole different problem and beyond the scope of this work. Of course every now and then someone shows up at the nursery and gives everyone the creeps, kind of makes you wonder.)
Plants of Borderline Hardiness
These may require a special site in the garden. The following conditions will often help your borderline plant survive and perform at its best:
Try planting near a heated building foundation.
If planting in the garden, place it under high overhead shade, but where late season sun will shine on the plants in the afternoon.
Pick a well-drained site or plant on a low mound of soil to help with drainage.
Mulch heavily in late fall after the plant is dormant. Avoid mulches that tend to get soggy and wet. Remove 2/3 of the mulch in spring after the danger of frost is past.
Avoid windswept sites and/or protect with a strategically placed windscreen of burlap or evergreen boughs.
Watch out for sun scorch. Plants that are hit by morning sun are often susceptible.
Don't be hasty to declare things dead in spring. Plants killed to the ground often come back and grow on into fine specimens