Hydrangeas include shrubs that are mostly deciduous with the exception of the stunning white climber. They come mainly in shrub form from miniature to large shrubs/small trees and feature showy white, pink or blue flowers made up of dozens of small blossoms in a variety of shapes. These eye-catching plants also have large, dark green leaves that, depending on variety, take on a really nice burgundy color in fall. Flowers and stems can be cut for fresh or dried arrangements.
With some varieties, most notably Hydrangea macrophylla including mophead and lacecap flower types, you can manipulate their color based on soil pH. The more acid that is available in the soil, the more blue their flowers will turn. Low acid (or heavily basic) soil will result in more of a pink flower color. You can achieve a variation of colors by alternately adding aluminum sulfate (acid) or garden lime (base) to your soil. Not all hydrangeas will change color depending on soil content. Plants that start off white in color cannot turn blue. These lighter varieties tend to take on a pink hue as the flower matures.
EXPOSURE – Part shade to full sun (6–8 hours or more) for best blooming.
WATER – Water regularly in the first season to establish a deep root system. After plants have become established, water thoroughly during dry periods
SOIL – Well-drained soil with plenty of organic matter will help the plants mature.
FLOWERING – Spring to summer, depending on species.
FERTILIZE – A general fertilizer such as Miracle-Gro in early spring will be sufficient. Amend with aluminum sulfate or elemental sulfur to achieve desired pink or blue color.
SPECIAL INSTRUCTIONS – Hydrangeas are especially spectacular when mass-planted. They are salt tolerant and therefore well-suited to seaside locations.
Some of the most frequent asked questions that we encounter at Briggs are “When do I prune my hydrangea?” and “Why isn’t my hydrangea flowering?”. These questions can be answered by finding out what type of hydrangea you have and how it blooms.
The best time to prune hydrangea is after they flower and before they set buds for next year. On some species, such as Hydrangea paniculata and arborescens, you can prune very heavily and it won’t affect next year’s bloom because they bloom on new growth. For most Hydrangea macrophylla, it you prune in early spring or late fall, you will cut off the bloom buds for next year’s flowers. These varieties bloom on old wood. There are newer, more improved types of hydrangea such as Endless Summer and Penny Mac on the market that bloom on old and new wood, resulting in long bloom seasons and not requiring such strict prune times.
If you are having problems getting your hydrangea to bloom, make sure you are pruning at the proper time according to species. If it still doesn’t bloom, the problem could be related to the soil, not enough light or the plant isn’t hardy enough for its environment. In some of the older macrophylla varieties like Nikko Blue, the flower buds freeze too severely in the winter to come through in the spring. Severe die back ensues and you end up cutting back all the flower buds and just having a green plant. You can try moving your plant to a sheltered location or wrapping it in burlap for extra protection. If this still doesn’t work, replace it with Endless Summer or Penny Mac.