The last week of July means you can continue to harvest fruits and vegetables, deadhead faded blooms from perennials and annuals and pay close attention to the watering needs of containers and hanging baskets.
This is also Part 2 of how to enjoy hydrangeas, so be happy that this handsome shrub loves to grow in Western Washington. Here are the most-asked questions about hydrangeas through the years.
Q. How does one change the color of hydrangeas? Pink is my favorite color. I have a white hydrangea and for two years I have added lime around the base of the plant but nothing happened.
A. Not all hydrangea varieties will change color. White hydrangeas stay white no matter what you add to the soil. The common mop head or hydrangea macrophylla will turn pink if the soil pH is above 6.5 and turn blue below 5.5. Anything in the middle becomes purple or lavender. In our naturally acid soil hydrangeas planted in the ground stay blue but in potting soil they lean toward pink. Adding sulfur (most often sold as aluminum sulfate) will make the soil acid and the flowers turn baby blue. A few cups of lime around the base of your hydrangea shrubs will slowly turn the soil less acid and more pink. Apply either of these products in fall or early spring and by summer your blooms will take on a different hue. – unless they are white or cream and stick with being neutral.
Q. How big will hydrangeas become? I want to try growing one in a container.
A. New, compact hydrangea varieties are best in a container as they can be pruned to stay less than 4 feet tall and still produce flowers. Most hydrangeas, especially the common big leaf mop head varieties and the Pee Gee varieties grow into giant shrubs up to 6 feet tall and 6 feet wide. Read plant labels at the nursery to discover the new dwarfs. Strawberry Sundae is a creamy white-turning-pink with pointed blooms, Edgy Hearts is a mop head that stays less than 3 feet, perfect for pots, while the Cityline series (Venice, Paris and other city names) will bloom on new and old wood so pruning them down one-third each spring will not prevent these hydrangeas from flowering each summer.
Q. What are the hydrangeas that take full sun? I have the blue variety but it wilts every afternoon when we have sunny weather.
A. Most of the paniculata or Pee Gee hydrangeas do best in full sun and can take the afternoon heat. The climbing hydrangeas and the oak leaf hydrangeas also stand up to summer heat. Perhaps the most impressive of all hydrangeas are the huge blooms of the Incrediball hydrangeas. These come in pink and white and are from a family called Smooth Hydrangeas or Hydrangea arborescens. These hydrangeas are not only sun-loving but great at tolerating super cold winter weather. Look for the Invincibelle series (Wee White, Mini Mauvette) and the much larger Incrediball series with flowers the size of basketballs.
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Marianne Binetti has a degree in horticulture from Washington State University and is the author of “Easy Answers for Great Gardens” and several other books. For book requests or answers to gardening questions, write to her at: P.O. Box 872, Enumclaw, 98022. Send a self-addressed, stamped envelope for a personal reply.
For more gardening information, she can be reached at her Web site, www.binettigarden.com.
Copyright for this column
owned by Marianne Binetti.