High pH makes hydrangeas pink

Published 12:00 am Friday, July 1, 2011

By Darrell Blackwelder
For the Salisbury Post
SALISBURY — July is poised to deliver the normal heat and excessively high humidity that we’ve learned to expect. Coping with the excessive elements often compounds other problems caused by insects and diseases as well as other general questions. Here are questions posed by local gardeners.
Q: From a woman attending the Salisbury Symphony Garden Tour last weekend, “How do I make my hydrangea blooms turn pink? They have always been various shades of blue.”
A: Generally, an acidic or low pH helps produce the blue color, and a higher pH or alkaline soil helps produce pink blossoms. Research at the University of Georgia indicates that higher aluminum content influences blueness more than pH.
More complete information can be found at www.hydrangeashydrangeas.com/colorchange.html. Newer hydrangea cultivars are bred to retain their color no matter the soil pH or aluminum levels.
Q: All of a sudden I have green June beetles swarming all over my yard. What can I do to control them?
A: The downpour we had Tuesday night loosened the soil and the adults have emerged right on schedule. Controlling the adults at this time is impractical. Controlling the larvae in the fall and spring is the best method of control. Effective control of the beetle larvae is mid-August until early September. Use a granular insecticide designed to kill soil insects and grubs.
Q: I had a total failure with my beets this spring. Is it possible for me to plant a fall planting? When is the best time for me to plant them?
A: Beets and other cool season vegetables can be planted in the fall. Count 10 weeks from the first fall frost which is generally the third week in October and direct-plant your beet seed. The planting date would be mid-August.
Q: My early pickling cucumbers were very bitter and did not taste good. What is the problem and what can I do to correct it?
A: Cucumber plants and their cousins contain a bitter compound called cucurbitacin, which is present in the fruit as well as the foliage. Bitterness and off- taste in cucumbers tends to be a problem when plants are under stress from low moisture and high temperatures, which we’ve experienced over the past few weeks. Generally as the weather becomes stable, there is less bitter taste in the later crop.
Darrell Blackwelder is the County Extension Director with horticulture responsibilities with the North Carolina Cooperative Extension Service in Rowan County. Learn more about Cooperative Extension events and activities by calling 704-216-8970 or online at www.rowanextension.com