Issue: May 10th, 1999

Hydrangeas in New Mexico

I was given five hydrangea plants [potted] that were used at a wedding. They were not watered for several days and looked very bad. I took them home and gave them a good drink of water with Miracle Grow. The next day, except for the leaves, they looked as good as new. The leaves were very dry on the outer edge. As I touched them, they crumbled. I have kept the potted [1 gal] plants well watered. Now the blooms are deteriorating.

Will they bloom again? If I put them in my garden, will they winter-over? What does one feed hydrangeas?

The hydrangeas should continue to grow and flower. The flowers look bad now because they had dried out. By the way, the flowers are really the little things at the center of what look like flowers. Those things that appear to be flowers are really bracts, modified leaves. These bracts wilted when the other leaves wilted and were dry long enough to dry out. They will probably not recover but, in time, new blossoms with the pretty bracts will form.

The plants may be kept in containers (but that is probably the more difficult way) or they may be planted in the soil. I have seen them growing well in Albuquerque on the east side of a home. A protected outdoor location, such as a courtyard or a location near the house (east side if protected from east winds or a partly shady location on the south side of the house) should be chosen if you plant them outside.

Perhaps you will choose to plant them outside but may want to keep some in pots for insurance. If so, you will need to watch them carefully so that they don't dry out. Plants in containers dry much more rapidly than those in the open ground. A light-colored container will reflect heat from the roots and prevent root damage from overheating.

The plants in pots will need to be transplanted every few years to avoid salt damage. Salt from our water accumulates in the soil each time we water the plants. The calcareous (high pH) nature of our soil will also affect the plants, both those in containers and plants in the ground. Hydrangeas grown in acid soil have blue bracts on their flowers, while those in alkaline soil (such as ours) tend to be pink. If you like the pink, you should have no problem. If you want blue bracts, you will need to work continually to acidify the soil by adding copperas or other sulfate materials that increase the acidity of the soil Be careful to follow the directions written on the package. These materials can burn the plants if not used properly. In addition to acidifying agents, a good flowering plant fertilizer will help, but select those which acidify the soil if you want blue flowers. If you like the pink, any good flowering plant fertilizer should be satisfactory.

Marisa Y. Thompson, PhD, is the Extension Horticulture Specialist, in the Department of Extension Plant Sciences at the New Mexico State University Los Lunas Agricultural Science Center, email: desertblooms@nmsu.edu, office: 505-865-7340, ext. 113.

For more gardening information, visit the NMSU Extension Horticulture page at Desert Blooms and the NMSU Horticulture Publications page.

Send gardening questions to Southwest Yard and Garden - Attn: Dr. Marisa Thompson at desertblooms@nmsu.edu, or at the Desert Blooms Facebook.

Please copy your County Extension Agent and indicate your county of residence when you submit your question!