The following was received via email: Hi, I have been much inspired by my visits to the Asian Garden in developing a woodland garden here on Salt Spring. Would someone be able to tell me about which hydrangeas are doing the best under the conifer canopy that you have there? My reading leads me to think that H. aspera and H. serrata might be fine in that much shade, and perhaps H. arborescens too. I would greatly appreciate any comments or advice. The rest of the message is here.
hydrangeas You are right, many Hydrangeas seem to do well in some shade, locally; however, the issue is more likely one of water availability. Like so many non-native plants, hydrangeas don't tolerate summer drought well, and require supplemental irrigation once our thin coastal soils run out of moisture (usually May to October). Under summer droughty conditions, any available shade is an advantage. Remember, too, that our native conifers are well-adapted to summer drought and are particularly good at extracting available moisture when it is available. In other words, an established conifer is a fierce competitor, so make sure you plant away from the roots. Hydrangeas are a pretty shade-tolerant bunch. Broad leaves held parallel to the ground usually indicates a shade-adapted plant. Any of the hydrangeas you mention would work well, but the H. arborescens cultivar usually sold is 'Annabelle', which has oversized flower heads. In the shade, this plant tends to flop badly.
