My friend Steve has urged me to periodically write about my experiences in the Denial Zone…so here’s a little something: We all know you can only go so far with the whole tropical thing in Portland if you’re not going to invest in a greenhouse. Those of us who try to mimic the tropical look realize that we have to seek out the temperate and a few sub-tropicals that give us that ‘feel’. Bold foliages are key. Architectural plants, and just as important strong foliage contrast. This is not the place for subtlety. Strappy, fuzzy, split and dissected, compound pinnate and palmate, glossy, drip tipped, bold variegation and wild patterns…over the years observant nurseryman and plant hunters have brought us a smorgasbord of unusually foliaged plants. Plant breeders have pushed the limits crossing hardy species in ways that mimic their tropical cousins, I’m thinking Hibiscus here. But still there are certain plants, certain forms and silhouettes, that are hard to replace.
Palms are one of these. Many of us grow various palmate forms like genus Trachycarpus, T. fortunei, most commonly, while others have used T. wagnerianus, T. takil and T. princeps. There are many others but of unproven hardiness. Another form of Palm are those with costapalmate fronds, of these I have a Sabal minor doing fine at home slowly getting bigger in the ground for the last four years, (It’s more than ten years old. I’m of the age now where I just say something is ten years old because it’s easier than checking. It may actually be 12-15.) and a Sabal x ‘Birmingham’ I have high hopes for probably destined for a few more years in the pot before I try it out in the ground. (The genus Sabal includes the Palmetto Palm native to the coastal southeastern US. They tend to be slower growing than Trachys, preferring more heat, often with larger more deeply segmented fronds. For those of you who don’t know, costapalmate are intermediate between palmate and pinnate. The stem extends into the frond where the segments separate and fan out. This extension may be slight as it is in Sabal minor. Instead of having the segments radiating evenly from one point at the base, the ‘base’ is slightly elongated stretching it as if it were briefly considering being pinnate. A casual look might leave the observer thinking that something is slightly off with what appears to be a palmate leaf.) Perhaps others will be found growing in the extremes of their home ranges that can take zn7 and 8 consistently with smiles. I planted the aforementioned Trachys over the last several years in and near Waterfront Park’s bowl. (Actually, the T. princeps is new this spring. Cross your fingers.) They are consistent and durable performers…even through last winter.
At home, at the top of my front stairs, it slopes rather steeply to the south facing sidewalk, is a Butia capitata, the South American Jelly Palm. One of the hardiest of the ‘feather’ type Palms, you know, like Coconut and Date Palms. I planted it out around 8 years ago after it had started to caliper up. My notes are vague here, but I think I set it out after the base had reached 5″+ in diameter. It was hard. I’d lost a couple other palms, one a Trachycarpus latisectus and the other a Jubaea chilense after planting them out at 3″ caliper and burying them in leaves. For those of you who don’t know, all Palms, are very slow to grow when young. Palms are monocots unlike all of the temperate trees we are familiar with. They don’t branch. They grow from one bud at ground level and for the first several years spend their energies growing roots and calipering up, growing the bud, and the tissues that protect it. At that point they begin to grow vertically and add caliper for just a few years longer. They don’t have bark, cambium, phloem or xylem tissue, at least not in they way with think about it. Their trunks don’t grow thicker with age. There are no growth rings. They do not attain their full hardiness until they reach their maximum caliper…which insulates the bud, the meristematic tissue, that produces all of the palms growth. This is why you don’t plant them out too small, even T. fortunei. The bud may lack the protection it needs during sustained cold periods. So, I planted my Butia at home and each winter wrapped its tapering trunk in fiberglass insulation and a tarp to keep that dry. Not the stiff bulky foliage. I did this for about three years.
Then we remodeled the front of our house. I dug it…and agonized…worried that it would never recover from the disturbance. I did this in May. It stayed in a very large pot all summer, somewhat shaded, until I could put it back in the fall. This would be the last winter that I protected the trunk. It sulked the next summer, probably regrowing roots and has grown with vigor ever since. (Many Palms shed their roots when dug and disturbed regrowing them from the base of the tree. Most other woody plants have woody roots that branch when cut. A common practice with many field grown woody plants is to root prune a plant with a spade the year before digging it to encourage root branching so that there is more root in a given root ball). While some winters have damaged some of the foliage, it quickly (Quickly is a relative term as it doesn’t grow near as fast as T. fortunei) grows healthy new fronds. I remove heavily damaged fronds and the others that are in decline (Remember, evergreens aren’t ‘forever-greens’. They hold their still functioning leaves through the following winter and for one to four and five years). You can see this Palm today from the street. It’s base has a 16″ caliper. The trunk quickly tapers down to just the stems of the fronds at 3′ high, while the fronds reach up and arch out at 9′. It seems very happy here.
Watching my Butia over the years and also being aware that these are often unsuccessful in Portland, it would be interesting to see how big the ‘failures’ were when they were planted out, what was done to protect them during their early years and what were the conditions on their particular micro-sites. When you are talking about plants that may be borderline it is very important to pay attention to the particulars and to make every accommodation that you can for the plant. Thinking of all these things when Eric Blaser, then of Evolving Gardens, approached me a couple of years ago about trying out a large, one brought in by lowboy trailer, Jubaea chilense, I was intrigued and nervous. He had told me California growers were very interested in finding new markets for their palms and were willing to go so far as to make some very good deals. A crated Jubaea with a 3′ thick trunk planted in a very prominent spot in downtown Portland. That’s what they wanted. I couldn’t find the necessary support within Parks. The Palms I had been planting were too much of stretch for many. So that idea fell by the waysides.
But I kept thinking about it. Did some more internet research. Visited Eric and his collection of Palms and decided to try a Butia x Jubaea cross he’d brought up from San Diego (Unwrapped in the back of his pickup is the story). It’s a beautiful little bluish feather Palm with fronds that arc much like a Butia but having a twist more characteristic of a Jubaea. Jubaea chilensis is the largest growing palm in the world, to 100′ tall or so with massive trunks. This should be considerably smaller as the Butia parent will slowly get to 20’…, but who knows. I bought one in a 24″ box and planted it in Jefferson Circle in Waterfront Park at the south end of the sea wall last October.
In late November I packed the trunk with leaves and wrapped it. Then I built a tent over it to keep off rainwater, which otherwise might find its way down along the new spears towards the bud and freeze. My tarp/ tent disappeared a couple of nights later, probably to a homeless person and then the week of freezing weather hit. I worried and fretted to the plant gods. I got no sign. Then it got real cold again in February. I began to lose my faith. I saw signs of death and rot as we moved into March and April everywhere. After removing the wrap and leaves I purposely stayed away. Then I retired.
In late May I came by the circle and saw the Palm still standing. It looked good from a distance. I worked my way into the center of the bed and gave the center spear a tug. It was solid. (When the buds freeze or rot, the spear, the newly emerging growth, can be easily pulled vertically away from the plant. This indicates that the bud is dead. The remaining growth will gradually decline. The plant, in that case, would be dead.) I was almost shocked. I’ve visited it several times since and it seems to be ‘happily’ growing.
Would it do okay for you? Do a critical site analysis before you invest. Downtown Portland is a heat island. Out along the seawall it is very exposed. If it’s blowing anywhere in Portland it usually is there. In other beds nearby there is Choisya and Gardenia that bloom consistently, and while their foliage may not always be pristine they perform well enough to stay. A few feet from the Palm is a very vigorous Pittosporum tobira ‘Variegata’ with nice foliage that blooms fragrantly each year. The soil in this planter is two feet of a blended sandy/loam, with compost and pumice. The old soil, clay and blue clay, had been excavated. So at this point I’m willing to bet, that with minimal protection during its early establishment years, this Butia x Jubaea will be successful into the future. We can all keep an eye on it.