If you were stranded on a desert island and were allowed to have one tree, which tree would you pick?  My choice would be the ‘Autumn Blaze’ maple, but I’m sure many of you would pick the flowering dogwood, Cornus florida.
      I base this on the popularity of these trees at our garden centre.  We sell dozens of them each year.  Unfortunately we also have to replace some of them because they don’t manage to make it through the first growing season.  I have a few theories to explain their sudden downfall and I’ll use this column to hopefully prevent further losses, and to help homeowners enjoy the beauty of these trees.
      It’s not difficult to understand why the dogwood is so popular.  A healthy tree in bloom is a treat in the spring.  The bracts, that part surrounding the actual bloom, which give us the white or pink colour, produce a breathtaking cloud-like effect.  A mature dogwood is enough to make you stop in the street to admire it (be sure to check your rearview mirror first!) and then proceed immediately to your nearest garden centre to purchase one.
      The problem is that our Okanagan Valley is not a close match to the native habitat of the dogwood.  Cornus florida is found in the eastern half of North America, often growing under taller trees where it can receive a bit of shade and the benefit of the leaf mould which develops as the leaves fall from above and decompose.  Humidity and rainfall are also higher in these areas and soils are generally acidic.  Are these the conditions in your garden?  They certainly aren’t in mine.  Our growing conditions are more like that of the desert island.
      Obviously we can grow flowering dogwoods here.  What else is causing cars to stop suddenly on the street in May?  So, what do you need to do in order to be successful with this tree?  First, consider the planting site.  Is it sheltered, or exposed to wind and heat all day?  Ideally there should be some protection from the afternoon sun, either from a wall or from larger trees.  Trees which are continually subjected to scorching winds and blistering heat will inevitably decline over time, even if they do make it through their first growing season.
      Secondly, what type of soil is it going into?  We can amend our soils with peat to make it more acidic, and with organic matter to improve the water retention or drainage.  Simply digging a hole in heavy clay or gravelly, thin soils and planting the dogwood will result in mortality sooner than later.  If you’re spending good money for this tree that you want so much, spend a bit more money and put in the effort to make sure that the soil is improved before you install.
      Finally, and most importantly, be obsessive about caring for the tree during its first growing season.  I’m not advocating a complete ignorance of your family, or the Canucks during the playoffs, but you do need to spend time with the dogwood.  Don’t let the tree’s root ball get dry, particularly this summer. The soil must be moist and the roots must stay cool for your tree to be happy, so an application of mulch over the root ball is vital.  Of course, don’t drown the poor tree either.  Watch closely to make sure the water is draining properly as the dogwood is not a strong swimmer.
      Next week I’ll tell you about some of the cultivars available, as well as the Cornus kousa and some interesting hybrids.