Conifers Gardening

“Cedars” Doing What Comes Naturally

Thuyas with maturing cones.

By Larry Hodgson

Question: I had a cedar hedge installed in June 2020 and the plants all passed the winter without any damage. However, the summer was very dry in our region and we had to water less than usual due to the watering restrictions that the city imposed.

Our cedars made beautiful young green shoots over the summer, but now they are drying out and dying. Am I going to lose them? I’m including a photo so you can see.

Josée Lavallee

Answer: No, you’re not going to lose your “cedars” (Thuja occidentalis), better called arborvitaes or thuyas. In fact, they are perfectly healthy.

Young cones on tbuya.
Young cones on tbuya. Photo: H. Zell, Wikimedia Commons

What you see are not dead stems due to drought damage, but simply cones. They may not look much like the pine cones you may be more used to, given their much smaller size (only 0.3 to 0.5 in/8 to 13 mm in length), but they serve the same purpose: cones produce the seeds that will give birth to the upcoming generation. After all, thuyas are conifers and the word conifer means cone-bearing.

Brown cones on thuya.
The cones will turn brown and open to release seeds. Photo: Sten Porse, Wikimedia Commons

The cones will turn fully brown when they reach maturity later this fall, then split open to release their seeds. They’ll hang on over the winter, but will eventually drop off, their job done.

Also, you probably won’t be seeing this phenomenon next year, as thuyas usually only produce cones every 2 to 5 years.

Preventing Fruiting

Female flowers on a thuya.
Female flowers appear discretely in spring. You can prune them off to prevent cone production. Photo: Hans, pixabay

If you really do want to prevent cones from forming in future years, study the plants in the spring (April to June, depending on the region). In years in which you see pinkish tips appear on the branches (these are female flowers), when you prune your hedge, got at it a bit more heavily than usual and remove them. Obviously, if you prune off the female flowers, there will be no cones that year.

That said, I suggest learning to see cone formation on thuyas as an added if minor attraction rather than a problem and just letting nature run its course. After all, thuya cones are an important source of food for many birds and animals, including chickadees, grosbeaks, pine siskins, nuthatches and red squirrels. Wouldn’t you want to invite them to your garden? 

Live and let live: an excellent motto for laidback gardeners!

Larry Hodgson is one of Canada’s best-known garden communicators. He has notably been editor-in-chief of HousePlant Magazine, Fleurs, Plantes et Jardins, À Fleur de Pot and Houseplant Forum magazines and is currently the garden correspondent for Le Soleil and radio garden commentator for CKIA-FM Radio. He has written for many garden publications in both the United States and Canada, including Canadian Gardening, Harrowsmith, Horticulture, Fine Gardening and Organic Gardening. He also speaks frequently to horticultural groups throughout Canada and the U.S. His book credits include The Garden Lover’s Guide to Canada, Complete Guide to Houseplants, Making the Most of Shade, Perennials for Every Purpose, Annuals for Every Purpose, and Houseplants for Dummies, as well as nearly 60 other titles in English and French. He is a past president of the Garden Writers Association (now Garden Communicators International) and the winner of the prestigious 2006 Garden Media Promoter Award offered by the Perennial Plant Association. He resides in Quebec City, Quebec, Canada.

1 comment on ““Cedars” Doing What Comes Naturally

  1. Redwoods do the same. I get questioned about it annually.

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