I don't like that phrase. Never have. It seems too dismissive, too hateful. Perhaps it is because the word denial has such an ugly connotation. It connotes someone that doesn't see reality...that is blind, stupid... perhaps it's because I don't like to think of myself as stupid...and why would any intelligent gardener go outside of his zones...be in denial...unless of course we're stupid; tempting fate, laughing in the face of nature?
I am not stupid. And I adore nature! So I have come up with a different terminology...Zonal Expansion. Now, doesn't that sound much more grand? More adventuresome? And really, all that we gardeners that try plants outside of our zones are is those kids in school that colored outside of the lines, or saw a palm tree as blue instead of green, or want a plant that we love to grow where we are. Right?
The problem is that some things are just not meant to be, there are what they are, they grow where they grow. Nature itself has evolved, or was created, depending on your personal belief system, to withstand where it is on this planet.
Last year I had a beautiful large specimen of Idesia Polycarpa. This amazing tree had been in my yard for many years. Even my good friend Dan Hiems was stymied by it at a party I had...
"What is this William?".
"Idesia Polycarpa Dan".
Then, because he is a great deal more intelligent then me, he had to ask what family it belonged to! I didn't know then and I still don't...
My point is this. Last summer when we had that terrific heat wave...it died own to the ground. Fortunately, it is growing from the ground again but still, such a glorious trunk, great canopy, beautiful structure...all gone in one week. It is classed from zone 6 to 9. But here is what I think...that heat wave was just too much for it. The stress was more than it could handle, it had become used to our mild, northwest climates. This was an especially brutal loss for me as it had been growing for so many years and had finally reached a size that was needless to say...impressive. I am turning the stump into a place for a bird-feeder...lemons into lemonade.
I ultimately do not know what killed it to the ground. What I DO know is this. Plants are uncanny when it comes to survival. We could learn much from them in this effect. They start, where all good things do, with their base, their roots. Roots are amazing little creatures in nature. They are able to withstand drastic adverse weather conditions, too much or hardly any water, winds, earthquakes and the ridiculous things that we gardeners do to them.
But in each environment on earth, plants have acquired very specific roots for where they are natively located. I mean really, how different is gardening in the west hills of Portland vs the valley floor. Or how about we compare Canby to my neighbor hood; the Rockwood district of Portland? Ridiculously different.
So we try to amend the soil, remove that which the plants we want desire and add that which they require. However, this is time consuming and really never ending. But still...I know I do it!
Lets look at tropical roots. Most of them are formed completely different that those in our area. They are able to withstand heat and water but not cold very well. That is why many tropicals won't survive here. They are very fibrous...not woody like an oak tree. They can certainly handle a few HOURS of cold and wet but not months or even days or hours. My brother Stephen lives in Houston. He lost all of the Queen Palms in his yard this year (and he, like me, loves palm trees) because of the unseasonably cold weather there. Even in Houston, gardeners long for Zonal Expansion.
So will I continue forcing nature to be something it isn't...well...yes. Because I love the tropics. But I can tell you that in the future I will be more selective about what I try. I have a dear friend in Salem. I did her yard about 10 years ago. Valarie still has a Kumquat tree I planted (which I KNEW would die) outside. It's facing south and under an eave but is still going a decade later...who knew??? Sometimes it's about something as simple as finding the perfect spot. Sometimes it's about luck. Sometimes it's about skill. Whatever it is, I know I will keep trying plants that are not hardy here. Why...because I believe in Zonal Expansion!