i think i'll stick with trial and error. thanks robin carrier ----- Original Message ----- From: "Rodger Whitlock" <totototo@telus.net> To: <pbs@lists.ibiblio.org> Sent: Sunday, November 27, 2011 1:35 PM Subject: Re: [pbs] Agapanthus africanus ssp. walshii On 26 Nov 2011, at 14:34, Kirby Fong wrote: > I bought three of these at a University of California at Irvine arboretum > plant sale years ago... One has survived. It is located about 10 feet > east > of the trunk of a camphor tree and within the drip line. It has formed a > small clump with three or four flowering scapes each summer. In my > climate, > it is green year round. This is a Mediterranean climate where it rains in > the winter. I water it in the summer. This is U.S.D.A. hardiness zone 9, > specifically 37°40´18.95�N 121°47´14.60�W at elevation 458 feet. > This > is in northern California. Since UCI is in southern California, I would > imagine most of the Agapanthus africanus ssp. walshii from their plant > sales > are in southern California, in or near Orange County. Stealing ideas from various other people, I've developed a very interesting way to graphically compare climates in different places, and applied it to a comparison of Livermore and Steenbras, where this agapanthus is native. To summarize: Both Livermore and Steenbras are Mediterranean climates, with dry summers and wet winters. Livermore gets a little cooler in the winter than does Steenbras, but the summer temperatures are about the same. Precipitation is another issue altogether. Steenbras has 5-15mm of precipitation monthly, year round, wetter in winter, dryer in summer. Livermore otoh has bone dry summers and extremely wet winters. Taking all in all, Steenbras experiences much less seasonal variation in precipitation. It would seem from this comparison, that in Livermore Agapanthus africanus walshii would need protection from winter wet and enough water in summer to keep it from total drought. Re that graphical method: Find climate data for the location you are interested in. Google is your friend; try googling "climate tbilisi" to find climatic data for the capital of Sakartvelo (to use the Georgians' own name for their country). Set up an X-Y chart, with monthly average precipitation, in mm, along the Y axis and monthly average temperature, in degrees Celsius, along the X axis. Draw the curve using a smoothed line, and mark the months on it. Put two such plots on one chart and you have an instant climatic comparison. For bulb fanciers, draw a straight line from (0,0) to any point where the monthly precipitation is twice the monthly temperature in the units recommended. This line represents, approximately, the boundary between drought conditions when transpiration exceeds precipitation. Credits: for the drought line, Hans Roemer, a botanist here who is a very skilled bulb grower. For the general chart layout, "Hythergraphs" from the 1950s "Climatic Atlas of Canada." I have a 47Kb example of such a chart, comparing Victoria, Algiers, and Batumi (in Sakartvelo), that I am willing to email to anyone who wants a copy. Note that it was prepared using Open Office, not Word. -- Rodger Whitlock Victoria, British Columbia, Canada