July 11, 2009

1 - Plant hollyhock seeds as they mature on the plant.

Yard and Garden July 11, 2009


You helped me a few years ago when I asked about pruning my holly shrub. Now, I have a question about how and when to plant hollyhock seeds. Some neighbors have beautiful flowers that I would like to grow. It seems to me I heard years ago that they would not bloom the first year, is that correct? Any suggestions about how and when to plant the seeds would be appreciated?

- Glen P.



Your friends are (almost) correct. Hollyhock plants are biennial plants that do not bloom in their first growing season. In their first growing season, like most biennials, they grow as short, rosetted, plants. Then during the winter they stop growing, but biochemical activity continues. The hormone giberellic acid accumulates in the dormant bud causing the formation of flower buds. After the weather warms, this hormone also causes the stem to elongate and flower. So, they require two growing seasons (within a twelve month period) to induce flowers. This provides us the information needed to plant the seeds so that the plants will successfully form flowers.

Hollyhocks are now maturing seeds in central New Mexico. Many gardeners just let the seeds fall to the ground and start new plants after they mature on the plant. July and August, when the seeds mature, are good times to plant hollyhock seeds. You can start the seeds in pots and transplant the seedlings as soon as they are large enough, or you can plant them directly in the garden. They sprout when there is moisture in late summer, and then grow as short, non-blooming plants until they go dormant in late fall. After they have overwintered in the garden, they should flower the next summer.

In our climate these plants (and some others) that are usually considered biennial plants may actually survive subsequent winters and live as a short-lived perennial, flowering for several summers.

The hollyhock is one of those old plants that "went out of fashion" for a while and is now again stylish. In many parts of New Mexico it never lost favor, but was less common. I am glad to see it back with its spectacular and colorful profusion.

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.


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