Spring Hydrangea Facts

When the first daffodil opens up, it’s a sure sign that spring is just around the corner. For gardeners, this is the season we’ve been waiting for all winter, but now it’s time to get outdoors and see what has happened whilst the green slept... And one plant that stands out all summer with vivid color is the Hydrangea.

Garden hydrangeas are dependable and forgiving so they are a good “starter” plant for a new gardener. It is said that fossils of hydrangeas have been found in North America that date back some 40 to 70 million years; and that those found in Asia date back at least 25 million years. Accordingly, hydrangeas can survive just about anything. All you need to do to continue this tradition is duplicate hydrangeas’ natural edge-of-forest growing conditions. Plant in sun or up to half-shade, with well-drained soil with good organic matter, and give them at least average moisture, more in full sun. They are fairly drought hardy but do best with adequate moisture.

Although it’s tempting to get the pruners and start snipping your hydrangeas, it is important to first learn a bit more about these plants because their maintenance can be tricky. It is important to know the individual requirements for the many types of hydrangeas to achieve maximum bloom and plant health.

• Two native hydrangeas are found in the eastern United States Hydrangea arborescens and Hydrangea quercifolia. H. arborescens, or smooth hydrangea, has small flowers and can be cut back because it will bloom on current season growth. Hydrangea quercifolia, or oakleaf hydrangea, blooms on old growth but may have dead wood as a result of winter damage. Cut back this dead wood below the winter injury.
  
  
• Early spring or fall are good times to plant your hydrangea. These plants require lots of water and do best in partial shade, although they can withstand morning sun if they receive shade in the afternoon. Be sure to mulch generously to conserve water.
  
  
• To change the color of your French hydrangea, or H. macrophylla, apply treatments in the fall several times and again in the spring before blooming. Remember, color is partially dependent on soil pH, although certain other environmental conditions can change it. Generally, a French hydrangea will produce blue flowers in a soil with a pH below 6.5 and pink flowers in a soil with a pH of 6.5 or higher. For blue flowers, add ¼ ounce of aluminum sulphate and ¼ ounce of sulphate of iron mixed in 1 gallon of water. Water your plant using no more than 2 gallons per plant, once in the fall and again in the spring before blooming. If you want a pink or light red hydrangea, sprinkle agricultural lime around the dripline of the shrub in the spring and fall. Lime will make a neutral or acidic soil more alkaline.
  Note: These applications may change the pH slowly, so be patient.
  
  
• Florist hydrangeas or French hydrangeas, Hydrangea macrophylla, are a major greenhouse crop that has been rapidly increasing. These hydrangeas are forced for spring blooming and sold in garden centers. While they are beautiful, they may not make the best outdoor plant. Due to their confinement in a small pot, the root system may not be well developed, and they may not be winter hardy. Hydrangeas have high water needs and unless the tin foil they generally come wrapped in is removed, they can sit in water, rotting the roots. If you choose to plant your florist hydrangea outside, remove all the blooms and plant as usual.
  
  
• New shoots may not be clearly visible in early spring, so be careful when clearing debris or mowing around them so they are not damaged.
  
  
• Hydrangeas need plenty of water so plan to water thoroughly once per week. More frequent watering may be necessary during hot dry weather.