Jane McGary wrote: "Jane Hendrix in her alpine fastness can obviously grow many plants that low-elevation gardeners struggle to keep," My "secret" is the insulating properties of all that snow I've been writing about. After we get about 6 inches of snowpack on the gardens (in late October to early November), the temperature at the contact point between the soil and the bottom of the snowpack is between +31 and +26 degrees F. --- not matter how cold the ambient temperature is. Even when the air temperature dropped to -15 degrees F., the temperature on the surface of the soil protected by snowcover was +26 degrees. Many climates worldwide have snow in winter (as evidenced by the Alpine-L "hot-stove league" in the past dozen days). But in many of those areas, the snowpack is not persistent, thinning or completely melting during a warm period, possibly in mid-January, or in some climates, the snowpack compacts into ice (my former situation in Chicago, Illinois). It's the air chambers in the snowpack that insulate the soil, just like the air pockets in the wool on a sheep keeps the sheep warm. And Jane M. said, "Cold is only one factor, and you also have to consider moisture, weather fluctuation vs. stability, drainage, exposure, maturity of the plant, and so on. Plants will often surprise you by surviving when and where they shouldn't, and also by dying when and where they shouldn't." Another limiting factor is the number of months of sunshine that may be available to a species from a foreign ecosystem. For example, even though my winter soil temperature would put me in Zones 9 to 10, frost-tender, tropical or desert species cannot survive in my garden because there is no light under a 3- to 5-foot deep snowpack for at least 6 months. The temperature of the soil during the active growing season is one of the most limiting factors. If the soil temperature at the root level becomes too warm, some species will wilt as if they are drought-stressed -- but they are not, and applying water may temporarily perk them up because, if the water temperature is significantly lower than the soil temperature, it will lower the soil temperature -- but only until the sun heats it up again. If that plant isn't moved to a cooler soil microclimate, it may soon die. If the temperature of the soil is too cold for a species that originates in a warm-soil climate (like the midwestern U. S. states), the plant may grow but its growth rate will be slower than in its native ecosystem and its flower production may either be sparse or non-existent. Soil pH can also severely affect the healthy growth of species. Most herbaceous flowering species grow best when the soil pH is between about 6.2 to 7.0 (7.0 is neutral; a lower number is acidic, down to 0; a higher number is alkaline, up to 14). Trying to change your soil pH to accommodate a species that natively grows in a significantly different soil pH can be easy or challenging, depending on your individual circumstances and how large an area you are trying to alter. Some species, such as those in the genus Brassica (cabbage, cauliflower, etc) are more prone to developing clubroot disease in acidic soils. Conversely, species that need acidic soil for proper growth, such as my native Vaccinium scoparium (Grouseberry) will decline and will eventually disappear if it is grown in a near-neutral to limy, alkaline soil. And, as Jane M. points out, plants DO have a way of surprising us. I germinated seeds of the common Anemone coronaria, which is rated Zone 7-10. This species is usually grown as an annual, in my Zone 4, from spring-purchased tubers and, indeed, the plants that arose from my spring-purchased tubers gave a wonderful show -- but for just that one season. The seed-grown plants, however, have continued to return and bloom for 3 years now. You'll never know until you try. Jane HendrixMountain View Experimental GardensPeak 7 Area - Breckenridge, Colorado U.S.A.Elevation: 10,000 feetUSDA Zone 4Website: http://www.picturetrail.com/hendrix
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