Hydrangeas perform well in the St. Louis area and the variety to choose from can be overwhelming. Most newer varieties of hydrangea bloom on both old and new wood, so pruning can be done whenever it’s convenient. Hydrangeas range in height from Bobo and the Let’s Dance series (2-3 ft. tall) to Limelight and Pinky Winky ( 6-8 ft. tall). With the wide selection of colors and heights, there’s sure to be a hydrangea that will suit your garden. The smaller varieties are even great in pots. These can be brought up close to the house, mulched and over wintered just fine. Hopefully this information will simplify your selection and narrow your choices.
Flower Color- Blue Verses Pink
All hydrangeas undergo some color change as their flowers mature, but only the bigleaf or mophead varieties can be manipulated from blue to pink or from pink to blue. Blue flowers are the result of a low ph or acidic soil, whereas pink flowers occur in high ph or basic soils. Hydrangeas in our area tend towards pink. Getting them to bloom blue requires soil amendment. We prefer Espoma’s Organic Soil Acidifier, which with time, will safely and effectively produce bluish flowers. You must apply the acidic feed on a regular basis, once a month during the active growing season, to maintain blue blossoms.
General Growing Tips
- Plant hydrangeas in moist, but well-drained soil.
- Contrary to popular knowledge, most hydrangeas benefit from some morning or late afternoon sun.
- The panicle hydrangeas, like Bobo and Limelight can tolerate the most sun but should be well mulched to maintain moisture and a cooler root environment.
- Hydrangeas have shallow roots, so they dry out quickly. Watch carefully during periods of high temperatures and/or drought.
- 2-3 inches of mulch benefits all hydrangeas when the summer approaches.