Posted On: July 2, 2015

Hydrangeas In Bloom

Our Hydrangea collection will reach full bloom in the coming week. These blue and pink beauties are an American garden classic. While most are small shrubs, some vining species exist. Hydrangea is a genus of about 75 species of flowering plants native to China and the Americas. There are two flower arrangements in hydrangeas: mop head flowers — large, round flower heads resembling pom-poms; or lace caps, which are airier flowers surrounded by loose bracts.

In most species, flowers are white, but some species have colorful florets that are blue, red, pink, light or dark purple. Their particular pigmentation is affected by soil pH. For H. macrophylla and H. serrata cultivars, the flower hue can be determined by the relative acidity of the soil: an acidic soil will usually produce flower shades closer to blue, whereas an alkaline soil will produce pinker flowers. This color change is caused by the presence of aluminum ions, which can be taken up by the plants.

While most people are familiar with the Hydrangea macrophylla and H. serrata varieties, the Oak leaf Hydrangea, Hydrangea quercifolia, is a beautiful native species. These plants are able to tolerate significant bits of draught, and adopt remarkable coloring in the fall. Our two favorite Oak leaf varieties are the ‘Snow Queen’ hydrangea, which has incredibly large flowers, and the ‘Snowflake’ hydrangea, gifted with amazing double blooms. Another favorite is the H. macrophylla variety, known as ‘Lady In Red,’ for its distinct red petioles, and bright, autumnal shade.

Hydrangeas can be pruned all year long, since dead wood and tip dieback can be clipped at any time. However, it is recommendable to trim them, for size and shape purposes, only once the plants have flowered. Typically, H. macrophylla, H. serrata and H. quercifolia varieties bloom on old wood, while Hydrangea paniculata and Hydrangea arborenses bloom on new wood.