How should you overwinter geraniums?

geraniums
Photo courtesy Marilyn Castle

by Connie Oswald Stofko

I got a question from a reader on how to overwinter geraniums:

Last year I held over my geraniums in the basement in a covered cardboard box. I shook most of the dirt from the roots before putting them in the box. First of the year I started sprinkling them with water while they were still dormant in the box in the basement. Later I brought them upstairs and planted them in potting soil. When they started showing signs of growth and when weather was appropriate I planted them outside. They are doing beautifully outside now. They are blooming very well. 
 
My question is I can’t recall if I put them root down or root up in the box. My neighbor and I want to do the same this fall and would appreciate your recommendation.
 
Marilyn Castle, Jamestown

Since I’m a writer and not a gardening expert, I often get questions from readers that I can’t answer. I often share these with my other readers, hoping that they can help.

I told Castle I would share her question, but I was confused and emailed her back. Why didn’t she just lay the plants down on their side?

In the meantime, I was paging through a book I bought at the Meet the Authors event held in August in Buffalo in conjunction with the conference of GWA: The Association of Garden Communicators. (You can see a list of the gardening books here. Contact Talking Leaves Bookstore— If they don’t have the title in stock, they can get it for you.)

The book I bought was Coffee for Roses: …and 70 Other Misleading Myths About Backyard Gardening by C.L. Fornari. Myth #12 was: Save geraniums by hanging them upside down in the basement.

Fornari says that, as far back as the early 1900s, gardeners have been advised to “shake the soil from the roots in the fall and hang the plants upside down in a cool, dark, damp basement or cave.” She notes wryly that today few of us have caves and no one wants a damp basement, but we’re still hearing this advice.

I agree about the caves and damp basements, and now I understand where Castle’s question is coming from.

It seems that whether the plant is stored upside down or right side up is beside the point.

The geraniums will survive being stored this way, Fornari said, because thick parts of the plant store carbohydrates that keep the plant alive through the winter. Geraniums can also survive being stored in other similar ways, such as setting the pot of geraniums as is in the basement or packing the stems in newspaper and storing them in a paper bag in a cool place.

However, Fornari recommends a different method that she says will give you more plants and bigger plants. She tells gardeners to keep the potted geranium in a sunny window (watering it) through winter. In January or February, take cuttings from the mother plant and you’ll have many healthy geranium starts.

Castle replied to the questions in my email, saying that she had used this method successfully many years ago as well as just this past season.

Last year she put the plants in a cardboard box and closed the lid, while in the past she covered them lightly with newspaper. After thinking about my question, she replied that she now thinks she probably set the plants in the box root down, but she didn’t see any reason they couldn’t be set on their side. She put the box in her basement, then opened the box in January, or even February or March. That’s when she starts lightly sprinkling them with water and leaves the box open to the light. When she begins to see growth, she brings the plants upstairs and puts each one in a flower pot with potting soil and sets them in her bay window. She plants them outside in May when the weather permits.

Have you heard of storing geraniums upside down? What works for you? Please leave a comment.

How to get your questions answered

Readers often contact me with questions that I can’t answer. I’m not a gardening expert– I’m a writer by profession. I interview knowledgeable people in order to provide you with great articles on Buffalo-NiagaraGardening.com.

So when someone asks a question I can’t answer, sometimes I post the question and rely on my readers to share their expertise. If you have advice for Castle, please leave a comment below. If you want to know the answer to this question, check back later to read the comments.

Sending a question to me to post can be helpful if you’re looking for a wide range of opinions and don’t mind waiting for the answer. If you want to try this route, email the question to me at connie@buffaloniagaragardening.com and I’ll pose it to my readers in an upcoming issue.

However, don’t send me questions:

  • To find out what is wrong with your plant
  • To identify a particular plant or insect
  • If you need an answer quickly

To find out specific information like that, ask the Master Gardeners with Cornell Cooperative Extension or turn to your local garden center. They can give you the information you need.

See some of our earlier questions and answers here.

4 Comments on “How should you overwinter geraniums?

  1. I have left my geraniums in pots in a bright glass room over the winter for several years. I plant them outside for the summer. They do fine

  2. I would love to leave the geraniums in their pots but I am always afraid of bringing in critters. One year I saved a plant just to try it. I shook off all the soil from the plant to almost bare root. I let the plant dry out in the garage for a few days and then wrapped it loosely in newspaper and place in a box in my basement. I brought it out in march and planted it in a pot and moved it outdoors after danger of frost. It bloomed beautifully that summer. Hope to do more plants this year but [plan to repot a couple and try the cutting method in spring. Geraniums always take up a big part of my gardening budget every summer. Would be great if I could save all of them. Just love them!!!

  3. I have successfully held geraniums over the winter in a not too sunny heated sunroom. They seem to do fine. I take cuttings starting in January, root them, pot them on as necessary & plant in the garden in May. Love saving plants.

    I also save coleus the same way & have had the same coleus- Dipped In Wine, for many years. Originally I procured (!) a cutting at the Biltmore gardens- AFTER asking permission. The staff was very nice about it & probably figured they wouldn’t have to cut the plant back themselves!

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