Hydrangeas are the number one googled flowering shrub on the internet. I’m not surprised, given their captivating beauty, but also because of the confusion that prevails concerning their care and pruning. No wonder my PowerPoint on Growing Honkin’ Hydrangeas is so popular. But a helpful resource available right now at your fingertips is on Espoma’s web site (Espoma is one of the largest manufacturers of natural and organic gardening products in the country). Their blog features two terrific pieces on caring for Hydrangeas. Tutoring includes site assessment, pruning, fertilizing, controlling insect and disease problems, adjusting flower color, and more. All from an organic perspective! Espoma offers the organic products to bring about the results you crave. (photo Hydrangea serrata ‘Tuff Stuff, Proven Winners)
Here is a timely tip for those of you with bigleaf or mountain Hydrangeas (Hydrangea macrophylla and Hydrangea serrata). If the flowers were not the blue or pink you hoped for (these are the only species of hydrangeas where the color can be adjusted with soil amendments), late summer or fall is a good time to correct this.
First do a soil pH test. You can buy easy-to-use testing kits at garden centers or take a sample to your county cooperative extension office. Many garden centers also offer this testing service. Blooms are rich blue/purple in acidic soil (pH in the 5’s, or a tad lower) and pink in neutral or alkaline soil (7.0 or higher). Lower pH with elemental sulfur; raise it with lime. Apply the appropriate mineral to the soil at the recommended rate (check the label for directions) to adjust the soil’s pH. It takes three to six months for a correction to occur.
A great reason for starting the adjustment now is so that next summer the blooms will be more to your liking! Learn more about adjusting soil pH on Espoma’s blog. (photo Hydrangea m. Cityline ‘Rio’, Proven Winners)