Oldhamii is good for screening since it grows very upright and doesn't lean outward. Others will take up more space. Oldhamii will probably grow closer to 50 feet tall in your area. There are dozens of varieties that will do well and grow tall in your area. Kt

I have to agree with Bahia, here. There is a reasonable level of resolution for these maps. Attempting additional "refinement" would only misinform. First of all, consider the questionable validity of the averaging methods being used: static climate maps are made by doing statistical averaging over different study periods (usually 12 years long). Algorithms are then used to interpolate data and draw isotherms between reporting stations. So the sample size is quite small, both in terms of the tiny amount of territory the reporting stations cover and the reach of time in the study period. The USDA map of 1990, therefore, looks different than the 1960 map because, in part, the 1974-1986 examination period used for 1990 did not include many major freeze events in the West. A more accurate way to show an average minimum temperatures map would be as an animation over, say, a 20-year period. That's how climate really is: it's fluid, changing from one year to the next. Think video, not snapshot. It's common to come across pat declarations of hardiness, i.e., "hardy to 28F," but such statements are laughable. Hardiness is not established by winter only. The nature of the growing season, exposure and soil quality have a lot to do with it. A plant hardy to 22F in Palm Springs where summers are hot and winters are dry, might die at 30F in Eureka where summers are cool and winters are wet. Finally, a map is only useful if there is a significant body of literature that will dedicate itself to its use. Sunset may have only its own Western Garden Book going for it, but what a book! After 30 years of using the Sunset WGB, I am increasingly impressed with its accuracy under periodic revision AND...its VALIDITY (the editors understand the limitations of attempts to pigeonhole climate). Many envelope pushers of zone envy along the northern third of the West Coast who have often complained that Sunset was "too conservative" are eating crow after Old Man Winter decimated their marginal plants last year. Climate maps SHOULD be conservative.

H. scheideana blooms every year for me here in Berkeley, and is certainly evergreen in a wind protected and dappled shade setting, with lots of fertilizer and water as long as it doesn't freeze. It truly is adapted to our cool winter weather, because it pushes both flowers and new foliage for me even when temps get down into the hight 30'sF. There are also several other more commonly available species that will also do as well outdoors as long as the foliage doesn't freeze. These include H. latispatha, H. spissa, H. bourgeana, H. aurantiaca, H. matthiasae. Some of these can be bought online from suppliers such as Aloha Tropicals, or Stokes Tropicals in Louisiana. There are a few other suppliers in Southern California, but they don't ship. For those here in the SF Bay Area, getting the H. scheideana thru Monterey Bay Nursery is probably the easiest solution. Don't count on any of them flowering if you can't get the plant through the winter without freezing, as we just don't get hot enough to get blooms on new growth in less than a year, like they can in south Florida. Anyone growing 30 kinds of Heliconia in California has quite a collection, but I am willing to bet that over half of those varieties need a lot of help to get through a wet/cold winter, and are even less likely to survive year round outdoors here in northern California. If you stick with the kinds from higher elevation cloudforests in Southern Mexico, you can have thriving blooming clumps. Check out the Palmetum at Lake Merritt in Oakland to see a large clump of H. scheideana in bloom now. I do have some friends growing them in Sunset zone 15 conditions rather than 16 or 17, but you risk losing them to frost and never seeing them bloom.

It appears that 3 of the 4 Samoan seedlings sprouts are making some progress with new growth. Don't know why but the 4th one of them seems to be near death, almost completely browned out. :( I've read the strong sun/heat can crack the husk too much and cause the plant to have a reduced resistance to the environment. Maybe sunburn, overwatering, underwatering? Maybe 100% success rate is asking too much. If it dies, I think I'm going to replace it with a Satakentia liukiuensis rather than another coconut palm.